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<front>
<journal-meta>
<journal-id journal-id-type="publisher-id">Front. Sustain. Food Syst.</journal-id>
<journal-title-group>
<journal-title>Frontiers in Sustainable Food Systems</journal-title>
<abbrev-journal-title abbrev-type="pubmed">Front. Sustain. Food Syst.</abbrev-journal-title>
</journal-title-group>
<issn pub-type="epub">2571-581X</issn>
<publisher>
<publisher-name>Frontiers Media S.A.</publisher-name>
</publisher>
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<article-meta>
<article-id pub-id-type="doi">10.3389/fsufs.2025.1735427</article-id>
<article-version article-version-type="Version of Record" vocab="NISO-RP-8-2008"/>
<article-categories>
<subj-group subj-group-type="heading">
<subject>Original Research</subject>
</subj-group>
</article-categories>
<title-group>
<article-title>How effective is the quality constraint mechanism of agricultural socialized services?&#x02014;Evidence from 1,138 farmers in Shandong, China</article-title>
</title-group>
<contrib-group>
<contrib contrib-type="author">
<name><surname>Yu</surname> <given-names>Lianghong</given-names></name>
<xref ref-type="aff" rid="aff1"><sup>1</sup></xref>
<role vocab="credit" vocab-identifier="https://credit.niso.org/" vocab-term="Writing &#x2013; original draft" vocab-term-identifier="https://credit.niso.org/contributor-roles/writing-original-draft/">Writing &#x2013; original draft</role>
<uri xlink:href="https://loop.frontiersin.org/people/3160596"/>
</contrib>
<contrib contrib-type="author">
<name><surname>Zheng</surname> <given-names>Shan</given-names></name>
<xref ref-type="aff" rid="aff2"><sup>2</sup></xref>
<role vocab="credit" vocab-identifier="https://credit.niso.org/" vocab-term="Writing &#x2013; review &amp; editing" vocab-term-identifier="https://credit.niso.org/contributor-roles/writing-review-editing/">Writing &#x2013; review &#x00026; editing</role>
<uri xlink:href="https://loop.frontiersin.org/people/2630721"/>
</contrib>
<contrib contrib-type="author" corresp="yes">
<name><surname>Zhang</surname> <given-names>Ying</given-names></name>
<xref ref-type="aff" rid="aff3"><sup>3</sup></xref>
<xref ref-type="corresp" rid="c001"><sup>&#x0002A;</sup></xref>
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<aff id="aff1"><label>1</label><institution>School of Advanced Agricultural Sciences, Peking University</institution>, <city>Beijing</city>, <country country="cn">China</country></aff>
<aff id="aff2"><label>2</label><institution>International Business School, Qingdao Huanghai University</institution>, <city>Qingdao</city>, <country country="cn">China</country></aff>
<aff id="aff3"><label>3</label><institution>School of Management, the Institute of Marine Development, Ocean University of China</institution>, <city>Qingdao</city>, <country country="cn">China</country></aff>
<author-notes>
<corresp id="c001"><label>&#x0002A;</label>Correspondence: Ying Zhang, <email xlink:href="mailto:yzhang@ouc.edu.cn">yzhang@ouc.edu.cn</email></corresp>
</author-notes>
<pub-date publication-format="electronic" date-type="pub" iso-8601-date="2026-01-08">
<day>08</day>
<month>01</month>
<year>2026</year>
</pub-date>
<pub-date publication-format="electronic" date-type="collection">
<year>2025</year>
</pub-date>
<volume>9</volume>
<elocation-id>1735427</elocation-id>
<history>
<date date-type="received">
<day>30</day>
<month>10</month>
<year>2025</year>
</date>
<date date-type="rev-recd">
<day>30</day>
<month>11</month>
<year>2025</year>
</date>
<date date-type="accepted">
<day>30</day>
<month>11</month>
<year>2025</year>
</date>
</history>
<permissions>
<copyright-statement>Copyright &#x000A9; 2026 Yu, Zheng and Zhang.</copyright-statement>
<copyright-year>2026</copyright-year>
<copyright-holder>Yu, Zheng and Zhang</copyright-holder>
<license>
<ali:license_ref start_date="2026-01-08">https://creativecommons.org/licenses/by/4.0/</ali:license_ref>
<license-p>This is an open-access article distributed under the terms of the <ext-link ext-link-type="uri" xlink:href="https://creativecommons.org/licenses/by/4.0/">Creative Commons Attribution License (CC BY)</ext-link>. The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.</license-p>
</license>
</permissions>
<abstract>
<p>Constraint mechanisms of agricultural socialized services have been widely established, but how effective is the quality constraint mechanism remains unclear. However, the existing literature has not provided an answer to this question. Therefore, this study theoretically analyzes the effect of quality constraint mechanism on agricultural socialized service and propose the hypothesis, then applies MESR model and 1,138 farmers survey data, empirically examines the impact of constraint mechanism. The study finds that: (1) The constraint mechanism has a positive impact on the quality of agricultural socialized services. Based on contract theory, the intermediary mechanisms focus on two aspects: implicit contracts of trust within familiar societies and explicit contracts of risk-sharing. (2) Under the consideration of counterfactual hypothesis, if farmers with low constraint do not construct constraint mechanisms, the quality of agricultural socialized services will decline by 22%. If farmers with high constraint do not construct constraint mechanisms, the quality of agricultural socialized services will decline by 33%. (3) The results of heterogeneity analysis show that the effect of quality constraint mechanisms on different farmers is in the order of part-time farmers, small-scale pure farmers, and large professional farmers. The influence of quality constraint mechanism on different crops is in the order of vegetable, corn, and wheat. Accordingly, the government should guide farmers in signing service contracts, optimize the service standards system. This study can provide both theoretical and practical guidelines for the construction of constraint mechanisms of agricultural socialized services.</p></abstract>
<kwd-group>
<kwd>agricultural socialization</kwd>
<kwd>agriculture</kwd>
<kwd>constraint mechanism</kwd>
<kwd>endogenous switching regression model</kwd>
<kwd>service quality</kwd>
</kwd-group>
<funding-group>
<funding-statement>The author(s) declared that financial support was received for this work and/or its publication. This study was supported by National Natural Science Foundation of China (72503011) and China Postdoctoral Science Foundation (2024M76012).</funding-statement>
</funding-group>
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<equation-count count="9"/>
<ref-count count="61"/>
<page-count count="13"/>
<word-count count="10195"/>
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<custom-meta-group>
<custom-meta>
<meta-name>section-at-acceptance</meta-name>
<meta-value>Agricultural and Food Economics</meta-value>
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</article-meta>
</front>
<body>
<sec sec-type="introduction" id="s1">
<label>1</label>
<title>Introduction</title>
<p>In a principal&#x02013;agent relationship, the agent may have its own interests and motives to take advantage of the information asymmetry, harming the interests of the principal, thus giving rise to the principal&#x02013;agent problem (<xref ref-type="bibr" rid="B13">Forges et al., 2024</xref>). Agricultural socialized service is a typical principal&#x02013;agent relationship between the farmers and service organizations. To save operation time and reduce fuel consumption and machinery depreciation, service organizations will take opportunistic behaviors (<xref ref-type="bibr" rid="B48">Xiao and Fang, 2025</xref>), such as replacing deep plowing with shallow plowing, sowing seeds at uneven densities, or allowing excessive leakage during harvest. These practices result in poor quality of agricultural socialized services and seriously harms the interests of farmers (<xref ref-type="bibr" rid="B43">Sui and Yu, 2025</xref>). In practice, constraint mechanisms are constantly being established to prevent the problem of low quality of agricultural socialized services. The contract is an important constraint tool in the principal&#x02013;agent relationship. Its clear and explicit terms can regulate the behavior of both parties and reduce potential disputes. If there are loopholes, unclear terms or lack of completeness in the principal&#x02013;agent contract, it may lead to disputes between the two parties in the implementation process (<xref ref-type="bibr" rid="B30">Luo and Su, 2023</xref>). Especially in the case of a complex principal&#x02013;agent relationship that involves multiple interests and multi-task execution, the importance of a complete contract is more prominent. Currently, the agricultural socialized service contract clearly agrees on the normative code of conduct and work standards that the service organization should abide by <xref ref-type="bibr" rid="B49">Xu et al. (2022)</xref>. It establishes a penalty mechanism for breach of contract, which punishes the service organization&#x00027;s misconduct, to ensure the quality of agricultural socialized services. So, how effective is the quality constraint mechanism of agricultural socialized services remains unclear. Has it effectively improved the quality of agricultural socialized services? This is the key scientific question that this study tries to answer.</p>
<p>According to the classical principal&#x02013;agent theory, the principal&#x02013;agent problem can be solved by means of incentives mechanisms (<xref ref-type="bibr" rid="B10">Dirzka and Acciaro, 2021</xref>; <xref ref-type="bibr" rid="B36">Monios and Fedi, 2023</xref>), supervision mechanisms (<xref ref-type="bibr" rid="B53">Yu et al., 2023</xref>), and constraints mechanisms (<xref ref-type="bibr" rid="B23">Liang Y. et al., 2025</xref>; <xref ref-type="bibr" rid="B29">Luo et al., 2025</xref>). However, in the practice of agricultural socialized services, it is difficult to implement incentives, because farmers are often unwilling to give extra agricultural surplus to motivate service organizations. Moreover, the supervision mechanism is also difficult to implement, because farmer&#x00027;s supervision capacity is weak (<xref ref-type="bibr" rid="B43">Sui and Yu, 2025</xref>). Farmers are more willing to choose to constrain the agricultural socialized service behaviors of service organizations. But, there are few studies on the constraint mechanism of agricultural socialized services. So, the existing studies do not provide a reasonable answer to the scientific question of the effect of quality constraint mechanism on agricultural socialized services.</p>
<p>Based on the above practice issues and theoretical gaps, this study theoretically elaborates the impact of constraint mechanisms on the quality of agricultural socialized services and proposes a theoretical hypothesis, applies the multinomial endogenous switching regression (MESR) model, empirically tests the impact of constraint mechanisms on the quality of agricultural socialized services based on the survey data of 1,138 farmers, then carries out the analysis of heterogeneity and robust test. The innovations of this paper are as follows.</p>
<p>First, research on agricultural socialized services typically relies on theories of division of labor, principal&#x02013;agent relationships, property rights, and transaction costs. In contrast, this study employs contract theory to analyze the effectiveness of constraint mechanisms in agricultural socialized services and their mediating variables. Second, existing studies focus on the cost-saving and income-generating effects of agricultural socialized services, but few studies pay attention to the quality issue of agricultural socialized services. This study focuses on how to improve the service quality and conducts theoretical and empirical analyses on the effectiveness of the constraint mechanism of agricultural socialized services to realize the innovation of research content. Third, academics commonly use propensity score matching (PSM) and difference in difference (DID) methods to solve the endogeneity, but the PSM method cannot correct the selectivity bias of unobservable, and the DID method cannot be used for cross-sectional data. In this study, we adopt the MESR model, which eliminates the effect of endogeneity by switching endogenous variables into exogenous ones, and also enables parameter estimation in counterfactual situations, making the estimation results more accurate and robust.</p></sec>
<sec id="s2">
<label>2</label>
<title>Literature review</title>
<sec>
<label>2.1</label>
<title>Research on the quality of agricultural socialized services</title>
<p>The literature on agricultural socialized services is relatively abundant. Scholars have studied the antecedents of agricultural socialized services (<xref ref-type="bibr" rid="B20">Li et al., 2023</xref>), the development status (<xref ref-type="bibr" rid="B55">Zhang et al., 2022</xref>; <xref ref-type="bibr" rid="B47">Wu et al., 2023</xref>), and the economic consequences (<xref ref-type="bibr" rid="B38">Qing et al., 2023</xref>), which include the impacts of agricultural socialized services on crop yields, and the transfer of agricultural labor (<xref ref-type="bibr" rid="B51">Yang and Li, 2023</xref>), farm household income (<xref ref-type="bibr" rid="B3">Baiyegunhi et al., 2019</xref>; <xref ref-type="bibr" rid="B40">Sang et al., 2023</xref>), and the impact of agricultural green technology adoption (<xref ref-type="bibr" rid="B26">Lin et al., 2022</xref>; <xref ref-type="bibr" rid="B42">Shi et al., 2024</xref>). Research indicates that agricultural socialized services exert significantly different impacts on various types of farming households (<xref ref-type="bibr" rid="B35">Mi et al., 2020</xref>; <xref ref-type="bibr" rid="B51">Yang and Li, 2023</xref>) and different land management scales (<xref ref-type="bibr" rid="B52">Yang and Zhang, 2023</xref>). Similarly, the effectiveness of agricultural socialized service constraints is influenced by multiple factors. The same constraint measures may yield varying outcomes across different crops and different service link, necessitating a categorized analysis.</p>
<p>However, there are insufficient research on the quality of agricultural socialized services. The quality of these services reflects farmers&#x00027; subjective assessment of service organization (<xref ref-type="bibr" rid="B43">Sui and Yu, 2025</xref>). Service providers often fail to deliver satisfactory services to clients. In agricultural socialized services, service organizations may exploit information asymmetry to engage in opportunistic behavior, thereby creating service quality risks (<xref ref-type="bibr" rid="B48">Xiao and Fang, 2025</xref>). Agricultural risks cause serious hazards (<xref ref-type="bibr" rid="B9">Ding and Xu, 2023</xref>; <xref ref-type="bibr" rid="B2">Bai et al., 2024</xref>; <xref ref-type="bibr" rid="B6">Chinnannan et al., 2024</xref>); therefore, preventing and controlling the risk is particularly important (<xref ref-type="bibr" rid="B16">Hui and Yong, 2023</xref>; <xref ref-type="bibr" rid="B33">Mastenbroek et al., 2024</xref>). So, constraining service organizations&#x00027; conduct is particularly crucial. Research on service quality in other industries provides insights for this study. Examples include taxi service quality and customer satisfaction (<xref ref-type="bibr" rid="B18">Kester et al., 2024</xref>), and e-commerce customer service quality (<xref ref-type="bibr" rid="B57">Zhang et al., 2024</xref>). However, these studies did not validate the effectiveness of quality constraint mechanisms. It should be noted that while agricultural socialized service constraint mechanisms can enhance service quality, the trade-off between constraint costs and benefits remains an important research topic.</p></sec>
<sec>
<label>2.2</label>
<title>Research on the constraint mechanisms</title>
<p>The principal&#x02013;agent problem can be solved by means of incentives, supervision, and constraints mechanisms. Existing research is also carried out from these three aspects. First, the principal&#x02013;agent problem is solved through incentives mechanisms (<xref ref-type="bibr" rid="B41">Schosser, 2019</xref>; <xref ref-type="bibr" rid="B10">Dirzka and Acciaro, 2021</xref>; <xref ref-type="bibr" rid="B36">Monios and Fedi, 2023</xref>). For example, public transport authorities in the UK use incentives to get bus operators to provide more and better public transport services (<xref ref-type="bibr" rid="B34">Mctigue et al., 2020</xref>). Superiors use incentives mechanisms to make subordinate units disclose their minimum operating costs (<xref ref-type="bibr" rid="B1">An et al., 2023</xref>). Stimulate agents to increase their efforts through reasonable incentive contracts to increase the proportion of high-quality primary products in the supply chain (<xref ref-type="bibr" rid="B28">Liu S. et al., 2024</xref>). A reasonable benefit distribution mechanism can help to solve the multiple principal&#x02013;agent relationship in China&#x00027;s collective construction land market (<xref ref-type="bibr" rid="B50">Yan et al., 2021</xref>). Incentivize employees with weak currencies to achieve work goals unrelated to wages (<xref ref-type="bibr" rid="B7">Corgnet et al., 2018</xref>).</p>
<p>Second, solving principal&#x02013;agent problems through supervision mechanisms (<xref ref-type="bibr" rid="B44">Viaggi et al., 2009</xref>; <xref ref-type="bibr" rid="B53">Yu et al., 2023</xref>). For example, the central government can address the inaction of local governments in environmental governance through environmental protection inspections (<xref ref-type="bibr" rid="B11">Dong et al., 2024</xref>) and rent-seeking behavior of local polluting firms (<xref ref-type="bibr" rid="B25">Lin and Xie, 2023</xref>). Alternatively, incentives and supervision mechanisms can be used at the same time. Studies have shown that incentives and supervision mechanisms developed by the central government can increase the motivation of local governments in responding to rainstorm warnings, and that the two mechanisms can be substituted for each other (<xref ref-type="bibr" rid="B31">Ma et al., 2024</xref>).</p>
<p>Third, the principal&#x02013;agent problem is solved through the constraint mechanism (<xref ref-type="bibr" rid="B54">Zhang and Li, 2025</xref>; <xref ref-type="bibr" rid="B14">Hao et al., 2025</xref>). Beyond the agricultural sector, scholars have conducted extensive research on constraint mechanisms, providing valuable insights and inspiration for this study. For example, constraint mechanism in taxi and ride-hailing services (<xref ref-type="bibr" rid="B19">Laeeque and Ali, 2025</xref>; <xref ref-type="bibr" rid="B17">Jaydarifard et al., 2025</xref>), digital platform economy (<xref ref-type="bibr" rid="B58">Zhang and Liu, 2025</xref>), service outsourcing industry (<xref ref-type="bibr" rid="B22">Liang W. et al., 2025</xref>), collaborative project delivery (<xref ref-type="bibr" rid="B37">Nwajei et al., 2022</xref>), bottom-up public complaints (<xref ref-type="bibr" rid="B11">Dong et al., 2024</xref>), and enterprises&#x00027; rent-seeking behavior (<xref ref-type="bibr" rid="B25">Lin and Xie, 2023</xref>). In the agricultural sector, constraint mechanisms can take the form of formal constraints such as institutional regulations or contracts. For instance, beef farming contracts constrain farmers&#x00027; environmental behaviors (<xref ref-type="bibr" rid="B23">Liang Y. et al., 2025</xref>), while corporate low-carbon disclosure systems impose constraints (<xref ref-type="bibr" rid="B60">Zhu et al., 2025</xref>). They can also take the form of informal constraints such as social norms and education or training. For example, the role of social norms in constraining farmers&#x00027; low-carbon behaviors (<xref ref-type="bibr" rid="B12">Feng et al., 2025</xref>) and the use of ecological protection education to constrain college students&#x00027; environmental behaviors (<xref ref-type="bibr" rid="B15">Hou et al., 2025</xref>; <xref ref-type="bibr" rid="B29">Luo et al., 2025</xref>). Research indicates that agricultural cooperatives should be regulated to prevent them from becoming tools that serve only a select few members (<xref ref-type="bibr" rid="B27">Liu G. et al., 2024</xref>). So, the principal can constrain the agent by constructing an optimal contract (<xref ref-type="bibr" rid="B4">Banerjee and Chakraborty, 2023</xref>), or constrain the agent by other technical means (<xref ref-type="bibr" rid="B37">Nwajei et al., 2022</xref>). Furthermore, the effectiveness of incentives and constraints may differ, raising the question of which approach is more effective&#x02014;a topic warranting further research. <xref ref-type="bibr" rid="B21">Li and Zhao (2025)</xref> found that both incentives and constraints mechanism can motivate farmers to protect farmland, but incentives proved more effective than constraints. Therefore, determining whether incentives or constraints mechanism are more effective in agricultural socialized services requires additional research.</p>
<p>In the practice of agricultural socialized services, it is difficult to implement incentives and supervision mechanisms such as the share of excess production. Farmers are often unwilling to give extra agricultural surplus to motivate service organizations to refrain from opportunistic behavior, and their own supervision capacity is weak (<xref ref-type="bibr" rid="B43">Sui and Yu, 2025</xref>). Farmers are more willing to choose to regulate the agricultural socialized service behaviors of service organizations through service standards, service evaluation and other constraint mechanisms, so as to prevent the problem of low quality of agricultural socialized services. However, there are few studies on the constraint mechanism of agricultural socialized services.</p></sec>
<sec>
<label>2.3</label>
<title>Research gaps</title>
<p>The existing literature on agricultural socialized services and their regulatory mechanisms provides a foundation for this study, but there remain several areas for improvement:</p>
<p>First, risk and return go hand in hand, and most existing studies focus on the cost-saving and income-generating effects of agricultural socialized services, but few studies pay attention to the quality issue of agricultural socialized services.</p>
<p>Second, research on agricultural socialized services typically relies on theories of division of labor, principal&#x02013;agent relationships, property rights, and transaction costs. However, research analyzing the quality of agricultural socialized services based on contract theory remains scarce.</p>
<p>Third, academics commonly use methods such as PSM and DID to solve the problems of selection bias and endogeneity, but the PSM method cannot correct the selectivity bias of unobservable, and the DID method cannot be used for cross-sectional data.</p></sec></sec>
<sec id="s3">
<label>3</label>
<title>Theoretical analysis</title>
<p>In the principal&#x02013;agent relationship, the inconsistency of interests between the principal and the agent is the root cause of the principal&#x02013;agent problem (<xref ref-type="bibr" rid="B13">Forges et al., 2024</xref>). The inconsistency of interests refers to the dissimilarity or mismatch of the interest objectives of both farmers and service organizations. In agricultural socialized services, farmers pursue agricultural output maximization, while service organizations pursue service profit maximization. When the interests of the principal and agent are inconsistent, the principal&#x02013;agent problem will inevitably arise (<xref ref-type="bibr" rid="B5">Bogle and Van Kooten, 2013</xref>; <xref ref-type="bibr" rid="B45">Vining and Richards, 2016</xref>). Generally, principal&#x02013;agent problems can be solved by constructing constraint mechanisms. Based on contract theory, this study examines the impact of constraint mechanisms on the quality of agricultural socialized services and the intermediary mechanisms involved, focusing on two aspects: implicit contracts within familiar societies and explicit contracts of risk-sharing.</p>
<sec>
<label>3.1</label>
<title>Implicit contracts constraint of trust in rural familiar societies</title>
<p>The implicit constraint mechanism of China&#x00027;s rural familiarity society enhances the quality of agricultural socialized services. In a familiarity society based on personal connections, farmers tend to have stronger trust in service organizations. The lack of trust will reduce the quality of agricultural socialized services (<xref ref-type="bibr" rid="B48">Xiao and Fang, 2025</xref>). Currently, the main constraint mechanism of agricultural socialized service comes from the rural familiarity society, service organizations will not reduce the quality of agricultural socialized service for the sake of face (<xref ref-type="bibr" rid="B39">Qiu et al., 2023</xref>), and it is difficult for service organizations to carry out the business of agricultural socialized service in the familiarity network if they vocalize the dispute with the farmers. Thus, to a certain extent, service organizations can be restrained from agricultural socialized service behavior and improve the quality of agricultural socialized service. In the process of building a national unified market for agricultural socialized services (<xref ref-type="bibr" rid="B32">Ma et al., 2025</xref>), it is necessary to transform from relationship governance to contractual governance (<xref ref-type="bibr" rid="B4">Banerjee and Chakraborty, 2023</xref>). Currently, local government agricultural management departments and industry associations are releasing model contracts, formulating service standards for agricultural socialized services, creating a directory of agricultural socialized service organizations, and constructing a credit system for agricultural socialized services, etc., to form a new contractual service constraint mechanism, which will indirectly improve the quality of agricultural socialized services.</p></sec>
<sec>
<label>3.2</label>
<title>Explicit contracts constraint of risk-sharing in agricultural socialized services</title>
<p>The explicit constraint mechanism of risk-sharing enhances the quality of agricultural socialized services. In addition to implicit constraints, quality risk-sharing is an explicit constraint mechanism for farmers and service organizations. On the one hand, the quality risk of agricultural socialized service is only borne by a single subject (<xref ref-type="bibr" rid="B43">Sui and Yu, 2025</xref>), and it is very easy for farmers or service organizations to unilaterally withdraw from the problem. The scientific and reasonable risk-sharing mechanism realizes the diversification of quality risks, significantly reduces the &#x0201C;worries&#x0201D; of the cooperation between service organizations and farmers, strengthens the confidence of each subject to steadily and continuously carry out the value co-creation of agricultural socialized services (<xref ref-type="bibr" rid="B46">Wang and Huan, 2023</xref>). On the other hand, the perfect risk-sharing mechanism realizes the reasonable sharing of quality risks among different subjects, maintains the stability of the gain-sharing order, and consolidates the interest relationship between service organizations and farmers. In practice, if the quality risk is more shared by farmers and less shared by service organizations, it will reduce service quality (<xref ref-type="bibr" rid="B43">Sui and Yu, 2025</xref>; <xref ref-type="bibr" rid="B48">Xiao and Fang, 2025</xref>). Accordingly, this study proposes the following hypothesis.</p>
<p><bold>H:</bold> The constraint mechanism positively affects the quality of agricultural socialized services.</p></sec></sec>
<sec id="s4">
<label>4</label>
<title>Empirical research design</title>
<sec>
<label>4.1</label>
<title>Model construction</title>
<p>The MESR model is applicable when individuals are categorized into two states, each with continuous outcome variables. Additionally, the model addresses endogeneity issues, where individuals&#x00027; choice behaviors and outcome variables exhibit bidirectional influence. In this study, the decision to establish a constraint mechanism is divided into two states, and the constraint mechanism and service quality are mutually causal. In decision-making contexts, farmers may face multiple alternative decisions and the decisions may affect each other, when the use of traditional single-item regression models may arrive endogenous. Therefore, the MESR model is suitable for this research. For this reason, this study adopts the MESR model proposed by <xref ref-type="bibr" rid="B8">Deb and Trivedi (2006)</xref> to analyze, the core idea of the model is to introduce potential choice equations and observed choice equations. The specific steps of the MESR model are as follows.</p>
<p>First, consider the farmers&#x00027; decision-making equation. Because the Probit model is applicable to ordered categorical variables, and the explanatory variables in this study are measured using a five-point Likert scale, this model is used for the analysis (see <xref ref-type="disp-formula" rid="EQ1">Equation 1</xref>). In the formula, <italic>probit</italic> denotes the probability of formulating service constraint mechanism, <italic>constraint</italic><sub><italic>n</italic></sub> denotes the explanatory variables, and <italic>Z</italic><sub><italic>n</italic></sub> is the control variables. &#x003B4;&#x02032; and <italic>m</italic> are the parameters to be estimated. &#x003BC;<sub><italic>n</italic></sub> is the random error.</p>
<disp-formula id="EQ1"><mml:math id="M1"><mml:mtable class="eqnarray" columnalign="left"><mml:mtr><mml:mtd><mml:mi>p</mml:mi><mml:mi>r</mml:mi><mml:mi>o</mml:mi><mml:mi>b</mml:mi><mml:mi>i</mml:mi><mml:mi>t</mml:mi><mml:mo>=</mml:mo><mml:msup><mml:mrow><mml:mi>&#x003B4;</mml:mi></mml:mrow><mml:mrow><mml:mi>&#x02032;</mml:mi></mml:mrow></mml:msup><mml:msub><mml:mrow><mml:mi>Z</mml:mi></mml:mrow><mml:mrow><mml:mi>n</mml:mi></mml:mrow></mml:msub><mml:mo>&#x0002B;</mml:mo><mml:mi>m</mml:mi><mml:mo>&#x000D7;</mml:mo><mml:mi>c</mml:mi><mml:mi>o</mml:mi><mml:mi>n</mml:mi><mml:mi>s</mml:mi><mml:mi>t</mml:mi><mml:mi>r</mml:mi><mml:mi>a</mml:mi><mml:mi>i</mml:mi><mml:msub><mml:mrow><mml:mi>t</mml:mi></mml:mrow><mml:mrow><mml:mi>n</mml:mi></mml:mrow></mml:msub><mml:mo>&#x0002B;</mml:mo><mml:msub><mml:mrow><mml:mi>&#x003BC;</mml:mi></mml:mrow><mml:mrow><mml:mi>n</mml:mi></mml:mrow></mml:msub></mml:mtd></mml:mtr></mml:mtable></mml:math><label>(1)</label></disp-formula>
<p>Second, consider the service quality determining equation. The equation for determining the quality of agricultural socialized services with a constraint mechanism (experimental group) is shown in <xref ref-type="disp-formula" rid="EQ2">Equation 2</xref>. The equation for determining the quality of agricultural socialized services without the constraint mechanism (control group) is shown in <xref ref-type="disp-formula" rid="EQ3">Equation 3</xref>, where <italic>quality</italic><sub><italic>na</italic></sub> and <italic>quality</italic><sub><italic>nb</italic></sub> denote the quality levels of agricultural socialized service in the experimental group and the control group, respectively. <italic>constraint</italic><sub><italic>na</italic></sub> and <italic>constraint</italic><sub><italic>nb</italic></sub> denote the influence variables of service quality constraint. &#x003B5;<sub><italic>na</italic></sub> and &#x003B5;<sub><italic>nb</italic></sub> are the random error terms.</p>
<disp-formula id="EQ2"><mml:math id="M2"><mml:mtable class="eqnarray" columnalign="left"><mml:mtr><mml:mtd><mml:mi>q</mml:mi><mml:mi>u</mml:mi><mml:mi>a</mml:mi><mml:mi>l</mml:mi><mml:mi>i</mml:mi><mml:mi>t</mml:mi><mml:msub><mml:mrow><mml:mi>y</mml:mi></mml:mrow><mml:mrow><mml:mi>n</mml:mi><mml:mi>a</mml:mi></mml:mrow></mml:msub><mml:mo>=</mml:mo><mml:msup><mml:mrow><mml:msub><mml:mrow><mml:mi>&#x003B2;</mml:mi></mml:mrow><mml:mrow><mml:mi>a</mml:mi></mml:mrow></mml:msub></mml:mrow><mml:mrow><mml:mi>&#x02032;</mml:mi></mml:mrow></mml:msup><mml:mi>c</mml:mi><mml:mi>o</mml:mi><mml:mi>n</mml:mi><mml:mi>s</mml:mi><mml:mi>t</mml:mi><mml:mi>r</mml:mi><mml:mi>a</mml:mi><mml:mi>i</mml:mi><mml:msub><mml:mrow><mml:mi>t</mml:mi></mml:mrow><mml:mrow><mml:mi>n</mml:mi><mml:mi>a</mml:mi></mml:mrow></mml:msub><mml:mo>&#x0002B;</mml:mo><mml:msub><mml:mrow><mml:mi>&#x003B5;</mml:mi></mml:mrow><mml:mrow><mml:mi>n</mml:mi><mml:mi>a</mml:mi></mml:mrow></mml:msub></mml:mtd></mml:mtr></mml:mtable></mml:math><label>(2)</label></disp-formula>
<disp-formula id="EQ3"><mml:math id="M3"><mml:mtable class="eqnarray" columnalign="left"><mml:mtr><mml:mtd><mml:mi>q</mml:mi><mml:mi>u</mml:mi><mml:mi>a</mml:mi><mml:mi>l</mml:mi><mml:mi>i</mml:mi><mml:mi>t</mml:mi><mml:msub><mml:mrow><mml:mi>y</mml:mi></mml:mrow><mml:mrow><mml:mi>n</mml:mi><mml:mi>b</mml:mi></mml:mrow></mml:msub><mml:mo>=</mml:mo><mml:msup><mml:mrow><mml:msub><mml:mrow><mml:mi>&#x003B2;</mml:mi></mml:mrow><mml:mrow><mml:mi>b</mml:mi></mml:mrow></mml:msub></mml:mrow><mml:mrow><mml:mi>&#x02032;</mml:mi></mml:mrow></mml:msup><mml:mi>c</mml:mi><mml:mi>o</mml:mi><mml:mi>n</mml:mi><mml:mi>s</mml:mi><mml:mi>t</mml:mi><mml:mi>r</mml:mi><mml:mi>a</mml:mi><mml:mi>i</mml:mi><mml:msub><mml:mrow><mml:mi>t</mml:mi></mml:mrow><mml:mrow><mml:mi>n</mml:mi><mml:mi>b</mml:mi></mml:mrow></mml:msub><mml:mo>&#x0002B;</mml:mo><mml:msub><mml:mrow><mml:mi>&#x003B5;</mml:mi></mml:mrow><mml:mrow><mml:mi>n</mml:mi><mml:mi>b</mml:mi></mml:mrow></mml:msub></mml:mtd></mml:mtr></mml:mtable></mml:math><label>(3)</label></disp-formula>
<p>Third, the treatment effect assessment equation. To objectively assess the impact of the constraint mechanism on the quality of agricultural socialized services, based on the counterfactual assumption, this study calculates the expected value of agricultural socialized service quality and compares the expected value of service quality with the actual value to measure the average treatment effect of agricultural socialized service quality. The expected value of agricultural socialized service quality in the case of a constraint mechanism is shown in <xref ref-type="disp-formula" rid="EQ4">Equation 4</xref>, and the expected value of agricultural socialized service quality in the case of an unconstrained mechanism is shown in <xref ref-type="disp-formula" rid="EQ5">Equation 5</xref>. Similarly, the service quality expectations faced by farmers with constraints in place in the absence of constraints are shown in <xref ref-type="disp-formula" rid="EQ6">Equation 6</xref>, and those faced by farmers without constraints in the presence of constraints are shown in <xref ref-type="disp-formula" rid="EQ7">Equation 7</xref>.</p>
<disp-formula id="EQ4"><mml:math id="M4"><mml:mtable class="eqnarray" columnalign="left"><mml:mtr><mml:mtd><mml:mi>E</mml:mi><mml:mrow><mml:mo>[</mml:mo><mml:mrow><mml:mi>q</mml:mi><mml:mi>u</mml:mi><mml:mi>a</mml:mi><mml:mi>l</mml:mi><mml:mi>i</mml:mi><mml:mi>t</mml:mi><mml:msub><mml:mrow><mml:mi>y</mml:mi></mml:mrow><mml:mrow><mml:mi>n</mml:mi><mml:mi>a</mml:mi></mml:mrow></mml:msub><mml:mo>|</mml:mo><mml:msub><mml:mrow><mml:mi>D</mml:mi></mml:mrow><mml:mrow><mml:mi>n</mml:mi></mml:mrow></mml:msub><mml:mo>=</mml:mo><mml:mn>1</mml:mn></mml:mrow><mml:mo>]</mml:mo></mml:mrow><mml:mo>=</mml:mo><mml:msub><mml:mrow><mml:mi>&#x003B2;</mml:mi></mml:mrow><mml:mrow><mml:mi>a</mml:mi></mml:mrow></mml:msub><mml:mi>c</mml:mi><mml:mi>o</mml:mi><mml:mi>n</mml:mi><mml:mi>s</mml:mi><mml:mi>t</mml:mi><mml:mi>r</mml:mi><mml:mi>a</mml:mi><mml:mi>i</mml:mi><mml:msub><mml:mrow><mml:mi>t</mml:mi></mml:mrow><mml:mrow><mml:mi>n</mml:mi><mml:mi>a</mml:mi></mml:mrow></mml:msub><mml:mo>&#x0002B;</mml:mo><mml:msub><mml:mrow><mml:mi>&#x003C6;</mml:mi></mml:mrow><mml:mrow><mml:mi>&#x003BC;</mml:mi><mml:mi>a</mml:mi></mml:mrow></mml:msub><mml:msub><mml:mrow><mml:mi>&#x003BB;</mml:mi></mml:mrow><mml:mrow><mml:mi>n</mml:mi><mml:mi>a</mml:mi></mml:mrow></mml:msub></mml:mtd></mml:mtr></mml:mtable></mml:math><label>(4)</label></disp-formula>
<disp-formula id="EQ5"><mml:math id="M5"><mml:mtable class="eqnarray" columnalign="left"><mml:mtr><mml:mtd><mml:mi>E</mml:mi><mml:mrow><mml:mo>[</mml:mo><mml:mrow><mml:mi>q</mml:mi><mml:mi>u</mml:mi><mml:mi>a</mml:mi><mml:mi>l</mml:mi><mml:mi>i</mml:mi><mml:mi>t</mml:mi><mml:msub><mml:mrow><mml:mi>y</mml:mi></mml:mrow><mml:mrow><mml:mi>n</mml:mi><mml:mi>b</mml:mi></mml:mrow></mml:msub><mml:mo>|</mml:mo><mml:msub><mml:mrow><mml:mi>D</mml:mi></mml:mrow><mml:mrow><mml:mi>n</mml:mi></mml:mrow></mml:msub><mml:mo>=</mml:mo><mml:mn>0</mml:mn></mml:mrow><mml:mo>]</mml:mo></mml:mrow><mml:mo>=</mml:mo><mml:msub><mml:mrow><mml:mi>&#x003B2;</mml:mi></mml:mrow><mml:mrow><mml:mi>b</mml:mi></mml:mrow></mml:msub><mml:mi>c</mml:mi><mml:mi>o</mml:mi><mml:mi>n</mml:mi><mml:mi>s</mml:mi><mml:mi>t</mml:mi><mml:mi>r</mml:mi><mml:mi>a</mml:mi><mml:mi>i</mml:mi><mml:msub><mml:mrow><mml:mi>t</mml:mi></mml:mrow><mml:mrow><mml:mi>n</mml:mi><mml:mi>b</mml:mi></mml:mrow></mml:msub><mml:mo>&#x0002B;</mml:mo><mml:msub><mml:mrow><mml:mi>&#x003C6;</mml:mi></mml:mrow><mml:mrow><mml:mi>&#x003BC;</mml:mi><mml:mi>b</mml:mi></mml:mrow></mml:msub><mml:msub><mml:mrow><mml:mi>&#x003BB;</mml:mi></mml:mrow><mml:mrow><mml:mi>n</mml:mi><mml:mi>b</mml:mi></mml:mrow></mml:msub></mml:mtd></mml:mtr></mml:mtable></mml:math><label>(5)</label></disp-formula>
<disp-formula id="EQ6"><mml:math id="M6"><mml:mtable class="eqnarray" columnalign="left"><mml:mtr><mml:mtd><mml:mi>E</mml:mi><mml:mrow><mml:mo>[</mml:mo><mml:mrow><mml:mi>q</mml:mi><mml:mi>u</mml:mi><mml:mi>a</mml:mi><mml:mi>l</mml:mi><mml:mi>i</mml:mi><mml:mi>t</mml:mi><mml:msub><mml:mrow><mml:mi>y</mml:mi></mml:mrow><mml:mrow><mml:mi>n</mml:mi><mml:mi>a</mml:mi></mml:mrow></mml:msub><mml:mo>|</mml:mo><mml:msub><mml:mrow><mml:mi>D</mml:mi></mml:mrow><mml:mrow><mml:mi>n</mml:mi></mml:mrow></mml:msub><mml:mo>=</mml:mo><mml:mn>0</mml:mn></mml:mrow><mml:mo>]</mml:mo></mml:mrow><mml:mo>=</mml:mo><mml:msub><mml:mrow><mml:mi>&#x003B2;</mml:mi></mml:mrow><mml:mrow><mml:mi>a</mml:mi></mml:mrow></mml:msub><mml:mi>c</mml:mi><mml:mi>o</mml:mi><mml:mi>n</mml:mi><mml:mi>s</mml:mi><mml:mi>t</mml:mi><mml:mi>r</mml:mi><mml:mi>a</mml:mi><mml:mi>i</mml:mi><mml:msub><mml:mrow><mml:mi>t</mml:mi></mml:mrow><mml:mrow><mml:mi>n</mml:mi><mml:mi>a</mml:mi></mml:mrow></mml:msub><mml:mo>&#x0002B;</mml:mo><mml:msub><mml:mrow><mml:mi>&#x003C6;</mml:mi></mml:mrow><mml:mrow><mml:mi>&#x003BC;</mml:mi><mml:mi>a</mml:mi></mml:mrow></mml:msub><mml:msub><mml:mrow><mml:mi>&#x003BB;</mml:mi></mml:mrow><mml:mrow><mml:mi>n</mml:mi><mml:mi>a</mml:mi></mml:mrow></mml:msub></mml:mtd></mml:mtr></mml:mtable></mml:math><label>(6)</label></disp-formula>
<disp-formula id="EQ7"><mml:math id="M7"><mml:mtable class="eqnarray" columnalign="left"><mml:mtr><mml:mtd><mml:mi>E</mml:mi><mml:mrow><mml:mo>[</mml:mo><mml:mrow><mml:mi>q</mml:mi><mml:mi>u</mml:mi><mml:mi>a</mml:mi><mml:mi>l</mml:mi><mml:mi>i</mml:mi><mml:mi>t</mml:mi><mml:msub><mml:mrow><mml:mi>y</mml:mi></mml:mrow><mml:mrow><mml:mi>n</mml:mi><mml:mi>b</mml:mi></mml:mrow></mml:msub><mml:mo>|</mml:mo><mml:msub><mml:mrow><mml:mi>D</mml:mi></mml:mrow><mml:mrow><mml:mi>n</mml:mi></mml:mrow></mml:msub><mml:mo>=</mml:mo><mml:mn>1</mml:mn></mml:mrow><mml:mo>]</mml:mo></mml:mrow><mml:mo>=</mml:mo><mml:msub><mml:mrow><mml:mi>&#x003B2;</mml:mi></mml:mrow><mml:mrow><mml:mi>b</mml:mi></mml:mrow></mml:msub><mml:mi>c</mml:mi><mml:mi>o</mml:mi><mml:mi>n</mml:mi><mml:mi>s</mml:mi><mml:mi>t</mml:mi><mml:mi>r</mml:mi><mml:mi>a</mml:mi><mml:mi>i</mml:mi><mml:msub><mml:mrow><mml:mi>t</mml:mi></mml:mrow><mml:mrow><mml:mi>n</mml:mi><mml:mi>b</mml:mi></mml:mrow></mml:msub><mml:mo>&#x0002B;</mml:mo><mml:msub><mml:mrow><mml:mi>&#x003C6;</mml:mi></mml:mrow><mml:mrow><mml:mi>&#x003BC;</mml:mi><mml:mi>b</mml:mi></mml:mrow></mml:msub><mml:msub><mml:mrow><mml:mi>&#x003BB;</mml:mi></mml:mrow><mml:mrow><mml:mi>n</mml:mi><mml:mi>b</mml:mi></mml:mrow></mml:msub></mml:mtd></mml:mtr></mml:mtable></mml:math><label>(7)</label></disp-formula>
<p>Accordingly, the mean of average treatment effect of the experimental group <italic>ATT</italic><sub><italic>n</italic></sub> and the mean of average treatment effect of the control group <italic>AUT</italic><sub><italic>n</italic></sub> can be calculated. Among them, the average treatment effect of agricultural socialized services quality with constraint mechanisms is the difference between <xref ref-type="disp-formula" rid="EQ7">Equation 7</xref> and <xref ref-type="disp-formula" rid="EQ4">Equation 4</xref>, and the calculation results of <italic>ATT</italic><sub><italic>n</italic></sub> are shown in <xref ref-type="disp-formula" rid="EQ8">Equation 8</xref>. Similarly, the mean treatment effect of agricultural socialized services quality without constraints is the difference between <xref ref-type="disp-formula" rid="EQ6">Equation 6</xref> and <xref ref-type="disp-formula" rid="EQ5">Equation 5</xref>, and the calculation results of <italic>AUT</italic><sub><italic>n</italic></sub> are shown in <xref ref-type="disp-formula" rid="EQ9">Equation 9</xref>.</p>
<disp-formula id="EQ8"><mml:math id="M8"><mml:mtable class="eqnarray" columnalign="left"><mml:mtr><mml:mtd><mml:mi>A</mml:mi><mml:mi>T</mml:mi><mml:msub><mml:mrow><mml:mi>T</mml:mi></mml:mrow><mml:mrow><mml:mi>n</mml:mi></mml:mrow></mml:msub><mml:mo>=</mml:mo><mml:mrow><mml:mo stretchy="false">(</mml:mo><mml:mrow><mml:msup><mml:mrow><mml:msub><mml:mrow><mml:mi>&#x003B2;</mml:mi></mml:mrow><mml:mrow><mml:mi>a</mml:mi></mml:mrow></mml:msub></mml:mrow><mml:mrow><mml:mi>&#x02032;</mml:mi></mml:mrow></mml:msup><mml:mo>-</mml:mo><mml:msup><mml:mrow><mml:msub><mml:mrow><mml:mi>&#x003B2;</mml:mi></mml:mrow><mml:mrow><mml:mi>b</mml:mi></mml:mrow></mml:msub></mml:mrow><mml:mrow><mml:mi>&#x02032;</mml:mi></mml:mrow></mml:msup></mml:mrow><mml:mo stretchy="false">)</mml:mo></mml:mrow><mml:mi>c</mml:mi><mml:mi>o</mml:mi><mml:mi>n</mml:mi><mml:mi>s</mml:mi><mml:mi>t</mml:mi><mml:mi>r</mml:mi><mml:mi>a</mml:mi><mml:mi>i</mml:mi><mml:msub><mml:mrow><mml:mi>t</mml:mi></mml:mrow><mml:mrow><mml:mi>n</mml:mi><mml:mi>a</mml:mi></mml:mrow></mml:msub><mml:mo>&#x0002B;</mml:mo><mml:mrow><mml:mo stretchy="false">(</mml:mo><mml:mrow><mml:msub><mml:mrow><mml:mi>&#x003C6;</mml:mi></mml:mrow><mml:mrow><mml:mi>&#x003BC;</mml:mi><mml:mi>a</mml:mi></mml:mrow></mml:msub><mml:mo>-</mml:mo><mml:msub><mml:mrow><mml:mi>&#x003C6;</mml:mi></mml:mrow><mml:mrow><mml:mi>&#x003BC;</mml:mi><mml:mi>b</mml:mi></mml:mrow></mml:msub></mml:mrow><mml:mo stretchy="false">)</mml:mo></mml:mrow><mml:msub><mml:mrow><mml:mi>&#x003BB;</mml:mi></mml:mrow><mml:mrow><mml:mi>n</mml:mi><mml:mi>a</mml:mi></mml:mrow></mml:msub></mml:mtd></mml:mtr></mml:mtable></mml:math><label>(8)</label></disp-formula>
<disp-formula id="EQ9"><mml:math id="M9"><mml:mtable class="eqnarray" columnalign="left"><mml:mtr><mml:mtd><mml:mi>A</mml:mi><mml:mi>T</mml:mi><mml:msub><mml:mrow><mml:mi>U</mml:mi></mml:mrow><mml:mrow><mml:mi>n</mml:mi></mml:mrow></mml:msub><mml:mo>=</mml:mo><mml:mrow><mml:mo stretchy="false">(</mml:mo><mml:mrow><mml:msup><mml:mrow><mml:msub><mml:mrow><mml:mi>&#x003B2;</mml:mi></mml:mrow><mml:mrow><mml:mi>b</mml:mi></mml:mrow></mml:msub></mml:mrow><mml:mrow><mml:mi>&#x02032;</mml:mi></mml:mrow></mml:msup><mml:mo>-</mml:mo><mml:msup><mml:mrow><mml:msub><mml:mrow><mml:mi>&#x003B2;</mml:mi></mml:mrow><mml:mrow><mml:mi>a</mml:mi></mml:mrow></mml:msub></mml:mrow><mml:mrow><mml:mi>&#x02032;</mml:mi></mml:mrow></mml:msup></mml:mrow><mml:mo stretchy="false">)</mml:mo></mml:mrow><mml:mi>c</mml:mi><mml:mi>o</mml:mi><mml:mi>n</mml:mi><mml:mi>s</mml:mi><mml:mi>t</mml:mi><mml:mi>r</mml:mi><mml:mi>a</mml:mi><mml:mi>i</mml:mi><mml:msub><mml:mrow><mml:mi>t</mml:mi></mml:mrow><mml:mrow><mml:mi>n</mml:mi><mml:mi>b</mml:mi></mml:mrow></mml:msub><mml:mo>&#x0002B;</mml:mo><mml:mrow><mml:mo stretchy="false">(</mml:mo><mml:mrow><mml:msub><mml:mrow><mml:mi>&#x003C6;</mml:mi></mml:mrow><mml:mrow><mml:mi>&#x003BC;</mml:mi><mml:mi>b</mml:mi></mml:mrow></mml:msub><mml:mo>-</mml:mo><mml:msub><mml:mrow><mml:mi>&#x003C6;</mml:mi></mml:mrow><mml:mrow><mml:mi>&#x003BC;</mml:mi><mml:mi>a</mml:mi></mml:mrow></mml:msub></mml:mrow><mml:mo stretchy="false">)</mml:mo></mml:mrow><mml:msub><mml:mrow><mml:mi>&#x003BB;</mml:mi></mml:mrow><mml:mrow><mml:mi>n</mml:mi><mml:mi>b</mml:mi></mml:mrow></mml:msub></mml:mtd></mml:mtr></mml:mtable></mml:math><label>(9)</label></disp-formula>
</sec>
<sec>
<label>4.2</label>
<title>Selection of variables</title>
<list list-type="simple">
<list-item><p>(1) Core explanatory variable. This study selects the constraint mechanism as the core explanatory variable. The constraint mechanism is the effectiveness degree of quality constraints on agricultural socialized services. Due to the lack of direct objective metrics for the constraint mechanism, the core explanatory variable is characterized by a five-point Likert scale, where 1 = very low, 2 = low, 3 = average, 4 = high, and 5 = very high.</p></list-item>
<list-item><p>(2) Explained variables. Based on the theoretical analysis, the explained variable selected in this study is agricultural socialized service quality. The quality of agricultural socialized services refers to the level of service provided by service organizations and the satisfaction of farmers when farmers entrust the management of agricultural production operations to these organizations. Service quality encompasses pre-production, mid-production, and post-production service quality. Pre-production service quality includes the quality of agricultural input supply, agricultural machinery supply, and farmland preparation. Mid-production service quality includes the quality of sowing, pest and disease control, and fruit harvesting. Post-production service quality includes the quality of product drying, storage, and processing. Farmers evaluate their satisfaction with the service quality provided by these organizations. In addition, to further explore the influence of the constraint mechanism on the service quality of different production links, the pre-production service quality, the mid-production service quality and the post-production service quality of farmers are selected as the explained variables. The quality of agricultural socialized services is based on farmers&#x00027; subjective evaluations, lacking direct objective measurement indicators. So, the quality of each type of service is characterized by a five-point Likert scale, where 1 = very bad, 2 = bad, 3 = average, 4 = good, and 5 = very good.</p></list-item>
<list-item><p>(3) Mediating and moderating variables. Based on theoretical analysis and drawing on relevant research, this study selects trust and contract as mediating variables and farm scale as a moderating variable. The trust variable indicates whether farmers trust the service organization. If the service organization is local to the village, trust = 1; if it is from outside the village, trust = 0. The contract variable indicates whether farmers have signed contracts with service organizations, specifying service standards and risk-sharing provisions. If farmers sign a contract with service organizations and share risks, then contract = 1. If no risk-sharing contract is signed, then contract = 0. Farm scale variable is the total area of cropland contracted by farmers. The mean-centered transformation was applied to the farm size variable to reduce multicollinearity and enhance the interpretability of regression coefficients.</p></list-item>
<list-item><p>(4) Control variables. At the individual level, drawing on related studies (<xref ref-type="bibr" rid="B59">Zhou et al., 2025</xref>), this study selects gender, age, education, and political profile as control variables. Among them, the variables gender, age, and education indicate the farmer household head&#x00027;s gender, age, and education level. Political profile indicates whether the household head is a member of the Communist Party of China (CPC) or not, and if so, it takes the value of 1; otherwise, it takes the value of 0. At the household level, according to related research (<xref ref-type="bibr" rid="B56">Zhang, 2024</xref>), this study selects health, position in the village, number of people working in agriculture, number of people working in the labor force, and participation in cooperatives as the control variables. Among them, health is the health status of farm household members. The number of farmers and workers indicates the number of laborers in the household who are working at home and working outside, respectively. Cooperative participation is a dummy variable for whether farmers participate in agricultural cooperatives. At the farmland level, drawing on the literatures (<xref ref-type="bibr" rid="B52">Yang and Zhang, 2023</xref>; <xref ref-type="bibr" rid="B24">Liao et al., 2025</xref>), soil fertility, irrigation convenience, plot dispersion are selected as the control variables. Among them, soil fertility and irrigation convenience are characterized by a five-point Likert scale, and plot dispersion is the number of plots owned by farmers. At the area level, plain, suburban, and distance are selected as control variables in this study. Among them, plain and suburban are the topographic features and economic characteristics of the area where the farm household is located, which are defined as dummy variables. Township distance is the distance of the farm household location from the township government office, which is characterized by a five-point Likert scale.</p></list-item>
</list>
<p>We conducted a multicollinearity test on the regression variables and found no collinearity among them, meaning the variables are independent. The definitions of the variables are shown in <xref ref-type="table" rid="T1">Table 1</xref>.</p>
<table-wrap position="float" id="T1">
<label>Table 1</label>
<caption><p>Variables and their measurements.</p></caption>
<table frame="box" rules="all">
<thead>
<tr>
<th valign="top" align="left"><bold>Type</bold></th>
<th valign="top" align="center"><bold>Variable</bold></th>
<th valign="top" align="center"><bold>Indicators and their calculation methods/units</bold></th>
</tr>
</thead>
<tbody>
<tr>
<td valign="top" align="left">Explained variable</td>
<td valign="top" align="center">Quality</td>
<td valign="top" align="center">Quality level of agricultural socialized services, Likert scale</td>
</tr>
<tr>
<td valign="top" align="left">Explanatory variable</td>
<td valign="top" align="center">Constraint</td>
<td valign="top" align="center">Effectiveness of constraints on socialized services, Likert scale</td>
</tr>
<tr>
<td valign="top" align="left" rowspan="2">Mediating variable</td>
<td valign="top" align="center">Trust</td>
<td valign="top" align="center">Whether farmers trust the service organization</td>
</tr>
 <tr>
<td valign="top" align="center">Contract</td>
<td valign="top" align="center">Whether farmers have signed contracts with service organizations</td>
</tr>
<tr>
<td valign="top" align="left">Moderating variable</td>
<td valign="top" align="center">Scale</td>
<td valign="top" align="center">Area of cultivated land contracted by farmers&#x00027; families (acres)</td>
</tr>
<tr>
<td valign="top" align="left" rowspan="15">Control variable</td>
<td valign="top" align="center">Sex</td>
<td valign="top" align="center">Sex of head of household, Male = 0, Female = 1</td>
</tr>
 <tr>
<td valign="top" align="center">Age</td>
<td valign="top" align="center">The age of farmer household head</td>
</tr>
 <tr>
<td valign="top" align="center">Education</td>
<td valign="top" align="center">Years of education completed by the head of household (year)</td>
</tr>
 <tr>
<td valign="top" align="center">Party</td>
<td valign="top" align="center">Whether the household head is a member of the CPC, No = 0, Yes = 1</td>
</tr>
 <tr>
<td valign="top" align="center">Cadres</td>
<td valign="top" align="center">Members of the family serving in the village, None = 0, Yes = 1</td>
</tr>
 <tr>
<td valign="top" align="center">Farmers</td>
<td valign="top" align="center">Total number of family members working in agriculture (persons)</td>
</tr>
 <tr>
<td valign="top" align="center">Workers</td>
<td valign="top" align="center">Total number of family members working (persons)</td>
</tr>
 <tr>
<td valign="top" align="center">Health</td>
<td valign="top" align="center">Health status of family members, five-point Likert scale</td>
</tr>
 <tr>
<td valign="top" align="center">Participation</td>
<td valign="top" align="center">Farmers&#x00027; participation in agricultural cooperatives, no = 0, yes = 1</td>
</tr>
 <tr>
<td valign="top" align="center">Fertility</td>
<td valign="top" align="center">Fertility of farmers&#x00027; contracted cropland, five-point Likert scale</td>
</tr>
 <tr>
<td valign="top" align="center">Irrigation</td>
<td valign="top" align="center">Ease of access to farm irrigation, five-point Likert scale</td>
</tr>
 <tr>
<td valign="top" align="center">Plot</td>
<td valign="top" align="center">Number of plots of farmland contracted by farmers (plots)</td>
</tr>
 <tr>
<td valign="top" align="center">Plain</td>
<td valign="top" align="center">Whether the administrative village is located in a plain, No = 0, Yes = 1</td>
</tr>
 <tr>
<td valign="top" align="center">Suburban</td>
<td valign="top" align="center">Whether the administrative village is located in suburban, No = 0, Yes = 1</td>
</tr>
 <tr>
<td valign="top" align="center">Distance</td>
<td valign="top" align="center">Distance of farm households from township seat, five-point Likert scale</td>
</tr></tbody>
</table>
</table-wrap></sec>
<sec>
<label>4.3</label>
<title>Data sources</title>
<list list-type="simple">
<list-item><p>(1) Research area. Shandong is a large agricultural province in China, and agricultural socialized services have achieved remarkable results, creating a &#x0201C;Qilu Model&#x0201D; of agricultural socialized services that is highly influential and exemplary in the whole country. Therefore, this study selects Shandong Province of China as the sample area, which is representative. To ensure that the sample can achieve a relatively uniform distribution within the overall geographical scope of Shandong Province, so as to more accurately and comprehensively reflect the actual situation of the province&#x00027;s agricultural socialized services, the research team selected 12 cities as study area from the east, middle and west, as well as the north and south of Shandong Province. After rigorous and meticulous screening, 20 counties with considerable business volume of agricultural socialized services were identified as sample survey areas. It contains Jimo, Jiaozhou, Pindu, Tengzhou, Wulian, Wenshang, Guangrao, Lizhen, Feixian, Linshu, Leiling, Qihe, Boxing, Huimin, Donge, Shanxian, Jiyang, Zhangqiu, Gaomi, Qingzhou.</p></list-item>
<list-item><p>(2) Sample selection and questionnaire. The stratified random sampling method was used in the specific sample selection process. First, in each selected sample county, three sample townships were reasonably selected on the basis of their geographical size and agricultural development characteristics. Subsequently, for each sample township, three representative administrative villages were further selected. Finally, in each sample village, the principle of random sampling is strictly adhered to ensure the randomness and objectivity of the sample. On this basis, the research team carried out household surveys and distributed questionnaires to the sample farmers. The authors conducted a comprehensive and in-depth tracking survey of the sample farm households in two waves between 2022 and 2023. Taking fully into account the complex reality of the continuous fragmentation of farm households in the current rural society, it is very likely that some of the sampled households did not participate in agricultural socialized services in the actual survey process. To ensure the validity and relevance of the survey data, we carried out a meticulous screening of the sampled households, and decisively excluded those who did not carry out socialized services. In the first round of farmer survey conducted in 2022, we obtained 582 valid questionnaires, and 556 valid questionnaires were obtained in the year 2023. When the valid questionnaires obtained in these 2 years were summarized and counted, the total number of valid questionnaires from farmers reached 1,138.</p></list-item>
<list-item><p>(3) Reliability and validity tests of questionnaire. Based on the questionnaire survey data, this study conducted reliability and validity tests on the variables measured using the Likert scale. Reliability analysis was employed to assess the dependability of the sample responses. Cronbach&#x00027;s alpha represents the most common and widely used measurement method. Results from SPSS software indicates that the Cronbach&#x00027;s alpha coefficients for service quality is 0.845, confirming the reliability of the scale. Validity analysis primarily encompasses content validity and construct validity. First, regarding content validity, this study validated the relevance and completeness of the questionnaire content through expert review. Findings indicate that all indicators comprehensively cover the various dimensions of service quality and constraint. Second, construct validity was assessed through confirmatory factor analysis to verify whether the indicators effectively reflect the latent structure of service quality, ensuring the theoretical soundness of the scale. The KMO is 0.888, Bartlett&#x00027;s test significance level is 5%. Construct reliability (CR) value in this study is 0.879, and average variance extracted (AVE) value is 0.622. Results are shown in <xref ref-type="table" rid="T2">Table 2</xref>. These results indicate that the Likert scale employed in this study possesses high construct validity.</p>
</list-item>
</list>
<table-wrap position="float" id="T2">
<label>Table 2</label>
<caption><p>Discriminant validity analysis results.</p></caption>
<table frame="box" rules="all">
<thead>
<tr>
<th valign="top" align="left"><bold>Variable</bold></th>
<th valign="top" align="center"><bold>Question item</bold></th>
<th valign="top" align="center"><bold>Factor loadings</bold></th>
<th valign="top" align="center"><bold><italic>T</italic></bold></th>
<th valign="top" align="center"><bold>CR</bold></th>
<th valign="top" align="center"><bold>AVE</bold></th>
</tr>
</thead>
<tbody>
<tr>
<td valign="top" align="left" rowspan="3">Quality</td>
<td valign="top" align="center">Quality of pre-production</td>
<td valign="top" align="center">0.769</td>
<td valign="top" align="center">18.362</td>
<td valign="top" align="center" rowspan="3">0.879</td>
<td valign="top" align="center" rowspan="3">0.622</td>
</tr>
 <tr>
<td valign="top" align="center">Quality of mid-production</td>
<td valign="top" align="center">0.840</td>
<td valign="top" align="center">20.882</td>
</tr>
 <tr>
<td valign="top" align="center">Quality of post-production</td>
<td valign="top" align="center">0.755</td>
<td valign="top" align="center">17.958</td>
</tr></tbody>
</table>
</table-wrap>
</sec></sec>
<sec id="s5">
<label>5</label>
<title>Regression results and analysis</title>
<sec>
<label>5.1</label>
<title>Baseline regression results and analysis</title>
<p>To form a comparison between the service constraint mechanism in the actual situation and the counterfactual hypothetical situation, and effectively circumvent the impact of sample selection bias on parameter estimation, this study analyzes the impact of constraint mechanism by using the MESR model, which is capable of overcoming the problem of endogeneity and providing a more accurate parameter estimation. In response to the above research design, this study groups the samples based on the level of service constraints, the constraint of agricultural socialized service is less than 2.5 for the low constraint group, and the constraint of agricultural socialized service is greater than or equal to 2.5 for the high constraint group. Using STATA15 software for regression analysis, with service constraint as the core explanatory variable and agricultural socialized service quality as the explained variable, the model estimation results are shown in the table below.</p>
<list list-type="simple">
<list-item><p>(1) Results and analysis of farmer decision-making model. As can be seen from <xref ref-type="table" rid="T3">Table 3</xref>, first the Wald test results are all significant at the 1% level, indicating that the Probit regression model is valid. The goodness-of-fit test statistic <italic>R</italic><sup>2</sup> also indicates that the overall fit is good. In summary, it can be concluded that the model fitting results are credible. Second, the effects of household head&#x00027;s gender, age, education level, whether party member or not, whether village cadre or not, whether plain or not, whether suburb or not, distance from the township, number of family farmers, plot dispersion, number of family laborers, health status, cooperative participation, soil fertility, irrigation accessibility variables on the decision-making of constraints are in line with the expectations.</p>
</list-item>
</list>
<table-wrap position="float" id="T3">
<label>Table 3</label>
<caption><p>Estimation results of decision equation for agricultural socialized services.</p></caption>
<table frame="box" rules="all">
<thead>
<tr>
<th valign="top" align="left"><bold>Variable</bold></th>
<th valign="top" align="center" colspan="2"><bold>Low constraint group</bold></th>
<th valign="top" align="center" colspan="2"><bold>High constraint group</bold></th>
</tr>
<tr>
<th/>
<th valign="top" align="center"><bold>Coefficient</bold></th>
<th valign="top" align="center"><bold>Standard error</bold></th>
<th valign="top" align="center"><bold>Coefficient</bold></th>
<th valign="top" align="center"><bold>Standard error</bold></th>
</tr>
</thead>
<tbody>
<tr>
<td valign="top" align="left">Sex</td>
<td valign="top" align="center">0.069</td>
<td valign="top" align="center">1.201</td>
<td valign="top" align="center">0.109</td>
<td valign="top" align="center">0.189</td>
</tr>
<tr>
<td valign="top" align="left">Age</td>
<td valign="top" align="center">0.216</td>
<td valign="top" align="center">0.231</td>
<td valign="top" align="center">0.291<sup>&#x0002A;&#x0002A;&#x0002A;</sup></td>
<td valign="top" align="center">0.078</td>
</tr>
<tr>
<td valign="top" align="left">Education</td>
<td valign="top" align="center">0.335<sup>&#x0002A;&#x0002A;&#x0002A;</sup></td>
<td valign="top" align="center">0.000</td>
<td valign="top" align="center">0.317</td>
<td valign="top" align="center">0.278</td>
</tr>
<tr>
<td valign="top" align="left">Party</td>
<td valign="top" align="center">0.361<sup>&#x0002A;&#x0002A;&#x0002A;</sup></td>
<td valign="top" align="center">0.037</td>
<td valign="top" align="center">0.311<sup>&#x0002A;&#x0002A;&#x0002A;</sup></td>
<td valign="top" align="center">0.011</td>
</tr>
<tr>
<td valign="top" align="left">Cadres</td>
<td valign="top" align="center">0.252<sup>&#x0002A;&#x0002A;&#x0002A;</sup></td>
<td valign="top" align="center">0.019</td>
<td valign="top" align="center">0.272<sup>&#x0002A;&#x0002A;&#x0002A;</sup></td>
<td valign="top" align="center">0.008</td>
</tr>
<tr>
<td valign="top" align="left">Farmers</td>
<td valign="top" align="center">0.105<sup>&#x0002A;&#x0002A;&#x0002A;</sup></td>
<td valign="top" align="center">0.009</td>
<td valign="top" align="center">0.169<sup>&#x0002A;&#x0002A;&#x0002A;</sup></td>
<td valign="top" align="center">0.000</td>
</tr>
<tr>
<td valign="top" align="left">Workers</td>
<td valign="top" align="center">&#x02212;0.053</td>
<td valign="top" align="center">0.183</td>
<td valign="top" align="center">&#x02212;0.112</td>
<td valign="top" align="center">0.184</td>
</tr>
<tr>
<td valign="top" align="left">Health</td>
<td valign="top" align="center">0.011</td>
<td valign="top" align="center">0.074</td>
<td valign="top" align="center">0.154</td>
<td valign="top" align="center">0.135</td>
</tr>
<tr>
<td valign="top" align="left">Participation</td>
<td valign="top" align="center">0.267<sup>&#x0002A;&#x0002A;&#x0002A;</sup></td>
<td valign="top" align="center">0.000</td>
<td valign="top" align="center">0.116</td>
<td valign="top" align="center">0.127</td>
</tr>
<tr>
<td valign="top" align="left">Fertility</td>
<td valign="top" align="center">0.326<sup>&#x0002A;&#x0002A;&#x0002A;</sup></td>
<td valign="top" align="center">0.064</td>
<td valign="top" align="center">0.397<sup>&#x0002A;&#x0002A;&#x0002A;</sup></td>
<td valign="top" align="center">0.007</td>
</tr>
<tr>
<td valign="top" align="left">Irrigation</td>
<td valign="top" align="center">0.146<sup>&#x0002A;&#x0002A;&#x0002A;</sup></td>
<td valign="top" align="center">0.003</td>
<td valign="top" align="center">&#x02212;0.315</td>
<td valign="top" align="center">0.284</td>
</tr>
<tr>
<td valign="top" align="left">Plot</td>
<td valign="top" align="center">0.199<sup>&#x0002A;&#x0002A;&#x0002A;</sup></td>
<td valign="top" align="center">0.004</td>
<td valign="top" align="center">0.196<sup>&#x0002A;&#x0002A;&#x0002A;</sup></td>
<td valign="top" align="center">0.000</td>
</tr>
<tr>
<td valign="top" align="left">Plain</td>
<td valign="top" align="center">0.017<sup>&#x0002A;&#x0002A;&#x0002A;</sup></td>
<td valign="top" align="center">0.005</td>
<td valign="top" align="center">0.241</td>
<td valign="top" align="center">0.312</td>
</tr>
<tr>
<td valign="top" align="left">Suburban</td>
<td valign="top" align="center">0.046<sup>&#x0002A;&#x0002A;&#x0002A;</sup></td>
<td valign="top" align="center">0.001</td>
<td valign="top" align="center">0.096</td>
<td valign="top" align="center">0.084</td>
</tr>
<tr>
<td valign="top" align="left">Distance</td>
<td valign="top" align="center">0.023</td>
<td valign="top" align="center">0.035</td>
<td valign="top" align="center">0.316<sup>&#x0002A;&#x0002A;&#x0002A;</sup></td>
<td valign="top" align="center">0.011</td>
</tr>
<tr>
<td valign="top" align="left">Constant term</td>
<td valign="top" align="center">1.416<sup>&#x0002A;&#x0002A;&#x0002A;</sup></td>
<td valign="top" align="center">0.085</td>
<td valign="top" align="center">4.153<sup>&#x0002A;&#x0002A;&#x0002A;</sup></td>
<td valign="top" align="center">0.074</td>
</tr>
<tr>
<td valign="top" align="left">Wald <italic>X</italic><sup>2</sup></td>
<td valign="top" align="center" colspan="2">235.873<sup>&#x0002A;&#x0002A;&#x0002A;</sup></td>
<td valign="top" align="center" colspan="2">125.382<sup>&#x0002A;&#x0002A;&#x0002A;</sup></td>
</tr>
<tr>
<td valign="top" align="left">Log Likelihood</td>
<td valign="top" align="center" colspan="2">3734.763</td>
<td valign="top" align="center" colspan="2">3972.642</td>
</tr>
<tr>
<td valign="top" align="left"><italic>R</italic><sup>2</sup></td>
<td valign="top" align="center" colspan="2">0.478</td>
<td valign="top" align="center" colspan="2">0.396</td>
</tr>
<tr>
<td valign="top" align="left">&#x003C1;</td>
<td valign="top" align="center" colspan="2">0.082<sup>&#x0002A;&#x0002A;</sup></td>
<td valign="top" align="center" colspan="2">0.043<sup>&#x0002A;&#x0002A;</sup></td>
</tr>
<tr>
<td valign="top" align="left">Test for difference in coefficients between groups</td>
<td valign="top" align="center" colspan="4">0.013<sup>&#x0002A;&#x0002A;&#x0002A;</sup></td>
</tr></tbody>
</table>
<table-wrap-foot>
<p><sup>&#x0002A;&#x0002A;</sup>, <sup>&#x0002A;&#x0002A;&#x0002A;</sup> indicate significant at the 5%, and 1% levels, respectively.</p>
</table-wrap-foot>
</table-wrap>
<p>In addition, after regressing the samples in two groups, direct comparison of the size of the coefficients will produce bias, so this study also conducted a test for the difference in coefficients between low constraint and high constraint groups. The criterion for determining the significance of the difference in coefficients between two groups is whether the interaction term is significant. Commonly used tests are Chow test, Suest test, and Fisher&#x00027;s Permutation test. According to the estimated results of Chow test of the interaction term model, the <italic>P</italic>-value of the test of difference in coefficients between groups is calculated to be 0.013. The results of the Suest test and the Fisher&#x00027;s Permutation test are basically similar, indicating that there is a significant difference between the low constraint group and the high constraint group.</p>
<list list-type="simple">
<list-item><p>(2) Results and analysis of treatment effect estimation model. It can be seen from <xref ref-type="table" rid="T4">Table 4</xref> that, on the one hand, the constraint mechanism in the group of low constraint has a positive treatment effect on the quality of agricultural socialized service with a significance level of 1%. The average treatment effect is 0.300, this indicates that for farmers with low levels of constraints, establishing constraint mechanisms can improve the quality of agricultural socialized services by 30%. So, the constraint mechanism has a positive effect on the quality of agricultural socialized services. The current actual service quality is 1.663. To achieve the desired effect, the constraint must be increased by at least 2 units. On the other hand, in the high constraint group, the constraint mechanism has a positive treatment effect on the quality of agricultural socialized services with a significance level of 1%. The average treatment effect is 1.093, this indicates that for farmers with high levels of constraints, establishing constraint mechanisms can improve the quality of agricultural socialized services by 109.3%. So, the constraint mechanism has a positive effect on the quality of agricultural socialized services. The current actual service quality is 4.378, which has achieved the desired effect.</p>
</list-item></list>
<table-wrap position="float" id="T4">
<label>Table 4</label>
<caption><p>Treatment effects of constraint mechanism of agricultural socialized service.</p></caption>
<table frame="box" rules="all">
<thead>
<tr>
<th valign="top" align="left"><bold>Groups</bold></th>
<th valign="top" align="center"><bold>A</bold></th>
<th valign="top" align="center"><bold>B</bold></th>
<th valign="top" align="center" colspan="2"><bold>C</bold> = <bold>A-B</bold></th>
<th valign="top" align="center"><bold>Quality decline rate (%)</bold></th>
<th valign="top" align="center"><bold>95% confidence interval</bold></th>
<th valign="top" align="center"><bold>DW test</bold></th>
</tr>
<tr>
<th/>
<th valign="top" align="center"><bold>Actual quality of services</bold></th>
<th valign="top" align="center"><bold>Quality under counterfactuals</bold></th>
<th valign="top" align="center"><bold>ATT</bold></th>
<th valign="top" align="center"><bold>ATU</bold></th>
<th/>
<th/>
<th/>
</tr>
</thead>
<tbody>
<tr>
<td valign="top" align="left">Low-constraint group</td>
<td valign="top" align="center">1.663</td>
<td valign="top" align="center">1.363</td>
<td valign="top" align="center">0.300<sup>&#x0002A;&#x0002A;&#x0002A;</sup></td>
<td valign="top" align="center">&#x02013;</td>
<td valign="top" align="center">22</td>
<td valign="top" align="center">[1.023, 2.571]</td>
<td valign="top" align="center">1.898</td>
</tr>
<tr>
<td valign="top" align="left">High-constraint group</td>
<td valign="top" align="center">4.378</td>
<td valign="top" align="center">3.285</td>
<td valign="top" align="center">&#x02013;</td>
<td valign="top" align="center">1.093<sup>&#x0002A;&#x0002A;&#x0002A;</sup></td>
<td valign="top" align="center">33</td>
<td valign="top" align="center">[3.196, 4.998]</td>
<td valign="top" align="center">2.015</td>
</tr></tbody>
</table>
<table-wrap-foot>
<p><sup>&#x0002A;&#x0002A;&#x0002A;</sup> indicate significant at the 1% levels.</p>
</table-wrap-foot>
</table-wrap>
<p>A cross-sectional comparison within the group revealed that the constraint mechanism was more effective for farmers in the high-constraint group than for those in the low-constraint group. This may be attributed to the stronger sense of contractual commitment among farmers in the high-constraint group. Therefore, the constraint mechanism should first be promoted among farmers with a higher contractual spirit. In summary, the constraint mechanism has a positive effect on the quality of agricultural socialized services, and hypothesis H is proved.</p>
<p>In addition, considering the counterfactual assumption, if the farmers in the low constraint do not take agricultural socialized service constraints, the estimation results show that the quality of agricultural socialized service will decrease from 1.663 to 1.363, with a decrease of 22%. It means that if farmers with low constraint do not construct constraint mechanisms, the quality of agricultural socialized services will decrease 22%. If farmers in the high constraint do not take agricultural socialized service constraints, the estimation results show that the quality of agricultural socialized services will decrease from 4.378 to 3.285, with a decrease of 33%. It means that if farmers with high constraint do not construct constraint mechanisms, the quality of agricultural socialized services will decrease 33%.</p></sec>
<sec>
<label>5.2</label>
<title>Analysis of mediating and moderating effects</title>
<list list-type="simple">
<list-item><p>(1) Analysis of mediating effects. Based on theoretical analysis, this section examines two pathways through which the constraint mechanism influences the quality of agricultural socialized services. Using trust level and risk-sharing contracts as mediating variables, regression analysis was conducted via a mediation effect model. The results are presented in Models 1&#x02013;6 of <xref ref-type="table" rid="T5">Table 5</xref>. First, regarding the trust mediation variable, the effect of constraints on trust is 0.102, with a significance level of 5%. Trust&#x00027;s effect on service quality is 0.139, with a significance level of 5%. The mediation effect of trust is confirmed, indicating that the constraint mechanism indeed influences the quality of agricultural socialized services through the trust pathway. This is particularly evident in cross-regional agricultural socialized services, where farmers generally trust local service organizations but exhibit lower trust in service providers outside their village or township. Consequently, non-local agricultural machinery operators typically need to find local intermediaries to connect with farmers when providing such services. Second, regarding the risk-sharing contract intermediary variable, the constraint mechanism&#x00027;s effect on risk-sharing contracts was 0.088, with a significance level of 10%. The impact of risk-sharing contracts on service quality is 0.114, with a significance level of 5%. The mediation effect test for risk-sharing contracts passes, indicating that constraint mechanisms do indeed influence the quality of agricultural socialized services through the risk-sharing pathway. This occurs because signing risk-sharing contracts binds the interests of service organizations to farmers, creating incentive compatibility. Consequently, service organizations will not engage in opportunistic behavior for their own benefit.</p></list-item>
<list-item><p>(2) Analysis of moderating effects. This study incorporates the interaction term between constraints and farm scale as a moderating variable into the model, yielding the moderation effect results shown in Model 7 of <xref ref-type="table" rid="T5">Table 5</xref>. We can know that the coefficient for the constraint variable is 0.153, significant at the 10% level. The coefficient for the interaction term is 0.095, significant at the 5% level. This indicates that farm scale exerts a positive moderating effect. Specifically, larger farm scale enhances the effectiveness of constraint mechanisms and elevate the quality of agricultural socialized services. Conversely, excessively small farms limit the efficacy of such mechanisms. This may stem from two factors: First, larger farmers typically possess stronger contractual awareness, greater social capital, and more robust claim-making capabilities, thereby exerting more effective constraints on service organizations. Second, service providers, seeking sustainable operations, are reluctant to compromise service quality for major clients.</p></list-item>
</list>
<table-wrap position="float" id="T5">
<label>Table 5</label>
<caption><p>Results of mediating and moderating effects.</p></caption>
<table frame="box" rules="all">
<thead>
<tr>
<th valign="top" align="left"><bold>Variable</bold></th>
<th valign="top" align="center" colspan="3"><bold>Mediating variable 1</bold></th>
<th valign="top" align="center" colspan="3"><bold>Mediating variable 2</bold></th>
<th valign="top" align="center"><bold>Moderating variable</bold></th>
</tr>
<tr>
<th/>
<th valign="top" align="center"><bold>Model 1</bold></th>
<th valign="top" align="center"><bold>Model 2</bold></th>
<th valign="top" align="center"><bold>Model 3</bold></th>
<th valign="top" align="center"><bold>Model 4</bold></th>
<th valign="top" align="center"><bold>Model 5</bold></th>
<th valign="top" align="center"><bold>Model 6</bold></th>
<th valign="top" align="center"><bold>Model 7</bold></th>
</tr>
<tr>
<th/>
<th valign="top" align="center"><bold>Quality</bold></th>
<th valign="top" align="center"><bold>Trust</bold></th>
<th valign="top" align="center"><bold>Quality</bold></th>
<th valign="top" align="center"><bold>Quality</bold></th>
<th valign="top" align="center"><bold>Contract</bold></th>
<th valign="top" align="center"><bold>Quality</bold></th>
<th valign="top" align="center"><bold>Quality</bold></th>
</tr>
</thead>
<tbody>
<tr>
<td valign="top" align="left">Constraint</td>
<td valign="top" align="center">0.191<sup>&#x0002A;&#x0002A;&#x0002A;</sup></td>
<td valign="top" align="center">0.102<sup>&#x0002A;&#x0002A;</sup></td>
<td/>
<td valign="top" align="center">0.191<sup>&#x0002A;&#x0002A;&#x0002A;</sup></td>
<td valign="top" align="center">0.088<sup>&#x0002A;</sup></td>
<td/>
<td valign="top" align="center">0.153<sup>&#x0002A;</sup></td>
</tr>
<tr>
<td valign="top" align="left">Trust</td>
<td/>
<td/>
<td valign="top" align="center">0.137<sup>&#x0002A;&#x0002A;</sup></td>
<td/>
<td/>
<td/>
<td/>
</tr>
<tr>
<td valign="top" align="left">Contract</td>
<td/>
<td/>
<td/>
<td/>
<td/>
<td valign="top" align="center">0.114<sup>&#x0002A;&#x0002A;</sup></td>
<td/>
</tr>
<tr>
<td valign="top" align="left">Constraint &#x000D7; Scale</td>
<td/>
<td/>
<td/>
<td/>
<td/>
<td/>
<td valign="top" align="center">0.095<sup>&#x0002A;&#x0002A;</sup></td>
</tr>
<tr>
<td valign="top" align="left">Control</td>
<td valign="top" align="center">Yes</td>
<td valign="top" align="center">Yes</td>
<td valign="top" align="center">Yes</td>
<td valign="top" align="center">Yes</td>
<td valign="top" align="center">Yes</td>
<td valign="top" align="center">Yes</td>
<td valign="top" align="center">Yes</td>
</tr>
<tr>
<td valign="top" align="left">Constant</td>
<td valign="top" align="center">4.027</td>
<td valign="top" align="center">4.053<sup>&#x0002A;&#x0002A;</sup></td>
<td valign="top" align="center">4.059<sup>&#x0002A;&#x0002A;&#x0002A;</sup></td>
<td valign="top" align="center">2.989<sup>&#x0002A;&#x0002A;</sup></td>
<td valign="top" align="center">3.763<sup>&#x0002A;&#x0002A;&#x0002A;</sup></td>
<td valign="top" align="center">4.733<sup>&#x0002A;&#x0002A;</sup></td>
<td valign="top" align="center">4.554</td>
</tr>
<tr>
<td valign="top" align="left"><italic><italic>R</italic><sup>2</sup></italic></td>
<td valign="top" align="center">0.265</td>
<td valign="top" align="center">0.301</td>
<td valign="top" align="center">0.298</td>
<td valign="top" align="center">0.334</td>
<td valign="top" align="center">0.411</td>
<td valign="top" align="center">0.389</td>
<td valign="top" align="center">0.277</td>
</tr></tbody>
</table>
<table-wrap-foot>
<p><sup>&#x0002A;&#x0002A;</sup>, <sup>&#x0002A;&#x0002A;&#x0002A;</sup> indicate significant at the 5% and 1% levels, respectively.</p>
</table-wrap-foot>
</table-wrap>
</sec></sec>
<sec id="s6">
<label>6</label>
<title>Heterogeneity analysis and robust test</title>
<sec>
<label>6.1</label>
<title>Heterogeneity analysis</title>
<list list-type="simple">
<list-item><p>(1) Heterogeneity of farmer types. Based on the above criteria for the division of farm household types, this study divides the sample farmers into large professional farmers, part-time farmers, and small-scale pure farmers. Then we estimate the three sub-samples separately, and obtains the results of the heterogeneity analysis distinguishing the farmer types, as shown in <xref ref-type="table" rid="T6">Table 6</xref>, Models 1&#x02013;3. As can be seen from the table, the constraint mechanism has a significant positive impact on the service quality of small-scale pure farmers, the service quality of part-time farmers, and the service quality of large professional farmers. This impact is, in order of magnitude, part-time farmers, small-scale pure farmers, and large professional farmers. This may be because most part-time farmers spend the majority of their time working away from home, and lack the time to supervise service organizations. Constraint mechanisms can address the shortcomings of on-site supervision for part-time farmers.</p></list-item>
<list-item><p>(2) Heterogeneity of different crops. The main crops of agricultural socialized services in the research area are wheat, corn and vegetables. For this reason, this study divides agricultural socialized service crops into three categories: wheat, corn, and vegetables. Then, estimates the three sub-samples separately, obtaining the results of the heterogeneity analysis distinguishing crop types as shown in <xref ref-type="table" rid="T6">Table 6</xref>, Models 4&#x02013;6. As can be seen from the table, the regression coefficient of constraint variable is all positive. It means that the constraint mechanism positively affects the agricultural socialized service quality of wheat, corn, and vegetable. The order of influence is:, vegetables &#x0003E; corn &#x0003E; wheat. This may be due to the high economic value of vegetables and the significant economic losses resulting from poor service quality. Constraint mechanisms can substantially reduce such losses.</p></list-item>
</list>
<table-wrap position="float" id="T6">
<label>Table 6</label>
<caption><p>Heterogeneity regression results for farmers and service quality types.</p></caption>
<table frame="box" rules="all">
<thead>
<tr>
<th valign="top" align="left"><bold>Variable</bold></th>
<th valign="top" align="center" colspan="3"><bold>Heterogeneity of farmer types</bold></th>
<th valign="top" align="center" colspan="3"><bold>Heterogeneity of crop types</bold></th>
</tr>
<tr>
<th/>
<th valign="top" align="center"><bold>Model 1</bold></th>
<th valign="top" align="center"><bold>Model 2</bold></th>
<th valign="top" align="center"><bold>Model 3</bold></th>
<th valign="top" align="center"><bold>Model 4</bold></th>
<th valign="top" align="center"><bold>Model 5</bold></th>
<th valign="top" align="center"><bold>Model 6</bold></th>
</tr>
 <tr>
<th/>
<th valign="top" align="center"><bold>Small-scale pure farmers</bold></th>
<th valign="top" align="center"><bold>Part-time farmers</bold></th>
<th valign="top" align="center"><bold>Professional farmers</bold></th>
<th valign="top" align="center"><bold>Wheat</bold></th>
<th valign="top" align="center"><bold>Corn</bold></th>
<th valign="top" align="center"><bold>Vegetable</bold></th>
</tr>
</thead>
<tbody>
<tr>
<td valign="top" align="left">Constraint</td>
<td valign="top" align="center">0.083<sup>&#x0002A;&#x0002A;</sup></td>
<td valign="top" align="center">0.132<sup>&#x0002A;&#x0002A;</sup></td>
<td valign="top" align="center">0.039<sup>&#x0002A;&#x0002A;</sup></td>
<td valign="top" align="center">0.096<sup>&#x0002A;&#x0002A;&#x0002A;</sup></td>
<td valign="top" align="center">0.115</td>
<td valign="top" align="center">0.185<sup>&#x0002A;&#x0002A;&#x0002A;</sup></td>
</tr>
<tr>
<td valign="top" align="left">Constant</td>
<td valign="top" align="center">3.707<sup>&#x0002A;&#x0002A;&#x0002A;</sup></td>
<td valign="top" align="center">3.743<sup>&#x0002A;&#x0002A;&#x0002A;</sup></td>
<td valign="top" align="center">3.733<sup>&#x0002A;&#x0002A;&#x0002A;</sup></td>
<td valign="top" align="center">3.759<sup>&#x0002A;&#x0002A;&#x0002A;</sup></td>
<td valign="top" align="center">3.713<sup>&#x0002A;&#x0002A;&#x0002A;</sup></td>
<td valign="top" align="center">3.781<sup>&#x0002A;&#x0002A;&#x0002A;</sup></td>
</tr>
<tr>
<td valign="top" align="left">Control</td>
<td valign="top" align="center">Yes</td>
<td valign="top" align="center">Yes</td>
<td valign="top" align="center">Yes</td>
<td valign="top" align="center">Yes</td>
<td valign="top" align="center">Yes</td>
<td valign="top" align="center">Yes</td>
</tr>
<tr>
<td valign="top" align="left"><italic><italic>R</italic><sup>2</sup></italic></td>
<td valign="top" align="center">0.306</td>
<td valign="top" align="center">0.535</td>
<td valign="top" align="center">0.288</td>
<td valign="top" align="center">0.537</td>
<td valign="top" align="center">0.534</td>
<td valign="top" align="center">0.560</td>
</tr></tbody>
</table>
<table-wrap-foot>
<p><sup>&#x0002A;</sup>, <sup>&#x0002A;&#x0002A;</sup>, <sup>&#x0002A;&#x0002A;&#x0002A;</sup> indicate significant at the 10%, 5%, and 1% levels, respectively.</p>
</table-wrap-foot>
</table-wrap></sec>
<sec>
<label>6.2</label>
<title>Robustness tests</title>
<p>To enhance the reliability of the above findings, this study conducts robustness tests from variable replacement test and the division of samples test.</p>
<list list-type="simple">
<list-item><p>(1) Robustness test of variable substitution. This study employs four new indicators to replace the explanatory variables for robustness testing. First, the data with zero values in the constraint mechanism are left-merged to 0, and it means the constraint mechanism is not constructed. The data with a number of adoptions greater than zero are right-merged to 1, which means the constraint mechanism is constructed. According to data processing above, the binary categorical independent variable data are formed. Second, the completeness of service contract terms can be used to represent constraint variable. Professional legal personnel evaluate the completeness of each contract, and higher contract integrity indicates the stronger constraints. Third, breach records can be used to represent constraint variable. The more breaches occur, the weaker the constraints become. Fourth, use third-party assessment scores from village collective to represent constraint variable. The village collective leader shall evaluate the performance of the service organization.</p></list-item>
</list>
<p>On this basis, regression analysis is carried out using the OLS model to compare whether there is a difference in the results. The regression results are shown in <xref ref-type="table" rid="T7">Table 7</xref>. In Model 1, it can be seen that the coefficients and significance of the model regression results are basically consistent with the benchmark regression model, which verifies the robustness of the model estimation results. In Model 2, contract completeness can enhance the quality of agricultural socialized services. In Model 3, breach records undermine the quality of agricultural socialized services. In other words, the fewer the breach records, the higher the service quality. In Model 4, Evaluation scores exert a positive influence on the quality of agricultural socialized services. It means the higher the third-party assessment scores, the better the service quality. The results from the above tests all indicate that the empirical results of the benchmark regression are robust.</p>
<list list-type="simple">
<list-item><p>(2) Robustness test of sample division. In this study, we take the sample division according to the area and links of agricultural socialized service, and conduct the robustness test through the sample replacement method. This study groups the samples according to the area of agricultural socialized service and the link numbers of agricultural socialized service. According to the average land contract size of Chinese farmers and the average land operation size of farmers in the sample area, this study takes 10 mu as the boundary and divides the sample into two sub-samples: &#x0201C;the area of agricultural socialized services is less than or equal to 10 mu&#x0201D; and &#x0201C;the area is greater than 10 mu.&#x0201D; The estimation results of the sample divided by the area of agricultural socialized services are shown in <xref ref-type="table" rid="T8">Table 8</xref>.</p></list-item></list>
<table-wrap position="float" id="T7">
<label>Table 7</label>
<caption><p>Robustness test results for independent variable substitution.</p></caption>
<table frame="box" rules="all">
<thead>
<tr>
<th valign="top" align="left"><bold>Variable</bold></th>
<th valign="top" align="center"><bold>Model 1</bold></th>
<th valign="top" align="center"><bold>Model 2</bold></th>
<th valign="top" align="center"><bold>Model 3</bold></th>
<th valign="top" align="center"><bold>Model 4</bold></th>
</tr>
<tr>
<th/>
<th valign="top" align="center"><bold>Quality</bold></th>
<th valign="top" align="center"><bold>Quality</bold></th>
<th valign="top" align="center"><bold>Quality</bold></th>
<th valign="top" align="center"><bold>Quality</bold></th>
</tr>
</thead>
<tbody>
<tr>
<td valign="top" align="left">Constraint</td>
<td valign="top" align="center">0.191<sup>&#x0002A;&#x0002A;&#x0002A;</sup></td>
<td/>
<td/>
<td/>
</tr>
<tr>
<td valign="top" align="left">Contract completeness</td>
<td/>
<td valign="top" align="center">0.142<sup>&#x0002A;&#x0002A;</sup></td>
<td/>
<td/>
</tr>
<tr>
<td valign="top" align="left">Breach records</td>
<td/>
<td/>
<td valign="top" align="center">&#x02212;0.175<sup>&#x0002A;&#x0002A;</sup></td>
<td/>
</tr>
<tr>
<td valign="top" align="left">Assessment scores</td>
<td/>
<td/>
<td/>
<td valign="top" align="center">0.189<sup>&#x0002A;</sup></td>
</tr>
<tr>
<td valign="top" align="left">Constant</td>
<td valign="top" align="center">3.775<sup>&#x0002A;&#x0002A;&#x0002A;</sup></td>
<td valign="top" align="center">2.531<sup>&#x0002A;&#x0002A;</sup></td>
<td valign="top" align="center">1.972<sup>&#x0002A;&#x0002A;</sup></td>
<td valign="top" align="center">3.006<sup>&#x0002A;&#x0002A;&#x0002A;</sup></td>
</tr>
<tr>
<td valign="top" align="left">Control</td>
<td valign="top" align="center">Yes</td>
<td valign="top" align="center">Yes</td>
<td valign="top" align="center">Yes</td>
<td valign="top" align="center">Yes</td>
</tr>
<tr>
<td valign="top" align="left"><italic>R</italic><sup>2</sup></td>
<td valign="top" align="center">0.293</td>
<td valign="top" align="center">0.302</td>
<td valign="top" align="center">0.376</td>
<td valign="top" align="center">0.298</td>
</tr></tbody>
</table>
<table-wrap-foot>
<p><sup>&#x0002A;</sup>, <sup>&#x0002A;&#x0002A;</sup>, <sup>&#x0002A;&#x0002A;&#x0002A;</sup> indicate significant at the 10%, 5%, and 1% levels, respectively.</p>
</table-wrap-foot>
</table-wrap>
<table-wrap position="float" id="T8">
<label>Table 8</label>
<caption><p>Robustness test results for the delimited sample.</p></caption>
<table frame="box" rules="all">
<thead>
<tr>
<th valign="top" align="left"><bold>Variable</bold></th>
<th valign="top" align="center" colspan="2"><bold>Model 1</bold></th>
<th valign="top" align="center" colspan="2"><bold>Model 2</bold></th>
</tr>
<tr>
<th/>
<th valign="top" align="center" colspan="2"><bold>Service area</bold> &#x02264; <bold>10 mu</bold></th>
<th valign="top" align="center" colspan="2"><bold>Service area</bold> &#x0003E; <bold>10 mu</bold></th>
</tr>
 <tr>
<th/>
<th valign="top" align="center"><bold>Coefficient</bold></th>
<th valign="top" align="center"><bold>Standard error</bold></th>
<th valign="top" align="center"><bold>Coefficient</bold></th>
<th valign="top" align="center"><bold>Standard error</bold></th>
</tr>
</thead>
<tbody>
<tr>
<td valign="top" align="left">Constraint</td>
<td valign="top" align="center">0.186<sup>&#x0002A;&#x0002A;&#x0002A;</sup></td>
<td valign="top" align="center">0.013</td>
<td valign="top" align="center">0.177<sup>&#x0002A;&#x0002A;&#x0002A;</sup></td>
<td valign="top" align="center">0.009</td>
</tr>
<tr>
<td valign="top" align="left">Constant</td>
<td valign="top" align="center">4.759<sup>&#x0002A;&#x0002A;&#x0002A;</sup></td>
<td valign="top" align="center">1.149</td>
<td valign="top" align="center">4.223<sup>&#x0002A;&#x0002A;&#x0002A;</sup></td>
<td valign="top" align="center">0.208</td>
</tr>
<tr>
<td valign="top" align="left">Control</td>
<td valign="top" align="center" colspan="2">Yes</td>
<td valign="top" align="center" colspan="2">Yes</td>
</tr>
<tr>
<td valign="top" align="left"><italic>R</italic><sup>2</sup></td>
<td valign="top" align="center" colspan="2">0.307</td>
<td valign="top" align="center" colspan="2">0.396</td>
</tr>
<tr>
<td valign="top" align="left">Difference between groups</td>
<td valign="top" align="center" colspan="4">0.058<sup>&#x0002A;&#x0002A;&#x0002A;</sup></td>
</tr></tbody>
</table>
<table-wrap-foot>
<p><sup>&#x0002A;&#x0002A;&#x0002A;</sup> indicate significant at the 1% levels.</p>
</table-wrap-foot>
</table-wrap>
<p>According to the regression results of Model 1 and Model 2, the significance level of the constraints variable and the coefficients size are generally consistent with the baseline regression. In addition, this study divides the sample into groups with and without village positions, and then conducts regressions separately to compare whether there are significant changes in the results. The results show that the estimation results in the model with and without positions are more consistent with those of the benchmark model, which verifies the robustness of the benchmark regression model estimation results. Furthermore, this study also adopts the truncated-tailed approach to sample censoring, eliminating outliers, and then conducting robustness tests, which are not shown due to space limitations.</p></sec></sec>
<sec id="s7">
<label>7</label>
<title>Conclusions and policy implications</title>
<sec>
<label>7.1</label>
<title>Conclusions</title>
<p>In the practical context of the continuous construction of agricultural socialized service constraints mechanism, according to contract theory, this study analyzes the implementation effect of agricultural socialized service quality constraints mechanism from the theoretical and empirical levels. Using data from 1,138 farmers in China, we apply the MESR model to empirically test the impact of constraints mechanism on agricultural socialized service quality. The main conclusions are as follows:</p>
<list list-type="simple">
<list-item><p>(1) The constraint mechanism has a positive impact on agricultural socialized service quality. Based on contract theory, the intermediary mechanisms focused on two aspects: implicit contracts within familiar societies and explicit contracts of risk-sharing. This result still holds after a series of robustness tests.</p></list-item>
<list-item><p>(2) Under the consideration of the counterfactual assumption, if farmers with low constraint do not construct constraint mechanisms, the quality of agricultural socialized services will decrease from 1.663 to 1.363, with a decrease of 22%. If farmers with high constraint do not construct constraint mechanisms, the quality of agricultural socialized services will decrease from 4.378 to 3.285, with a decrease of 33%.</p></list-item>
<list-item><p>(3) The results of heterogeneity analysis show that the effect of constraint mechanisms on the service quality of different farmer types is in the order of part-time farmers, small-scale pure farmers, and large professional farmers. The influence of the constraint mechanism on the quality of different crops is in the order of vegetable, corn, and wheat.</p></list-item>
</list></sec>
<sec>
<label>7.2</label>
<title>Policy implications</title>
<list list-type="simple">
<list-item><p>(1) We should require the signing of agricultural socialized service contracts, specifying the decision-relevant elements, including scope and quality KPIs, inspection frequency and method, penalty ranges and triggers, timelines for claims/ADR, third-party oversight, public disclosure, and complaint/blacklist processes. Then we can pair them with a simple roadmap that clarifies roles for local government, cooperatives, providers, and third parties, indicative timelines and resource needs, and a small set of monitoring indicators such as coverage, compliance, re-inspection failure, and complaint rates.</p></list-item>
<list-item><p>(2) The standards of agricultural socialized services should be optimized. When formulating service standards, the contents of services, operational procedures and technical requirements should be specified and defined. For example, clear numerical requirements should be given for key indicators such as planting density, so that they can be implemented by service organizations. Service standards should be regularly evaluated, and the standard system should be updated in a timely manner in accordance with market demand and technological progress. Monitor the effectiveness of the implementation of the service standards and listen to feedback from farmers and service organizations on a regular basis, so as to continuously improve and enhance the quality and applicability of the service standards.</p></list-item>
<list-item><p>(3) For part-time farmers, enhance the transparency of service information and the rapid dispute resolution mechanism. In addition, the government should establish a credit evaluation system of agricultural socialized service for different types of farmer. Establish a credit database system and agricultural socialized service platform to record and manage trustworthy operation and dishonest behavior. The rating results will be made public and transparent in the village committee office to urge service organizations to consciously maintain a good credit record. For high-value crops such as vegetables, we can promote third-party quality inspection. For mid-production and single link, we should strengthen service quality constraints. The government should establish a directory of agricultural socialized services and set entry thresholds. Service organizations with poor quality will be subject to disciplinary measures to restrict their activities in the agricultural socialized service market.</p></list-item>
</list></sec></sec>
</body>
<back>
<sec sec-type="data-availability" id="s8">
<title>Data availability statement</title>
<p>The raw data supporting the conclusions of this article will be made available by the authors, without undue reservation.</p>
</sec>
<sec sec-type="ethics-statement" id="s9">
<title>Ethics statement</title>
<p>Ethical review and approval was not required for the study on human participants in accordance with the local legislation and institutional requirements. Written informed consent from the [patients/ participants OR patients/participants legal guardian/next of kin] was not required to participate in this study in accordance with the national legislation and the institutional requirements.</p>
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<sec sec-type="author-contributions" id="s10">
<title>Author contributions</title>
<p>LY: Writing &#x02013; original draft. SZ: Writing &#x02013; review &#x00026; editing. YZ: Conceptualization, Writing &#x02013; review &#x00026; editing, Resources.</p>
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<sec sec-type="COI-statement" id="conf1">
<title>Conflict of interest</title>
<p>The author(s) declared that this work was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.</p>
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<title>Generative AI statement</title>
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<p>Edited by: <ext-link ext-link-type="uri" xlink:href="https://loop.frontiersin.org/people/1576763/overview">Xin Wang</ext-link>, Longyan University, China</p>
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<p>Reviewed by: <ext-link ext-link-type="uri" xlink:href="https://loop.frontiersin.org/people/2990591/overview">Lei Luo</ext-link>, Sichuan Agricultural University, China</p>
<p><ext-link ext-link-type="uri" xlink:href="https://loop.frontiersin.org/people/3247691/overview">Ravi Kumar Bommisetti</ext-link>, Akal University, India</p>
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