Air pollution has brought about many problems, such as smog, and has become one of the world’s biggest public health challenges (Hanna and Oliva, 2015). Epidemiological and economic studies indicate that outdoor air pollution causes 3.3 million premature deaths per year globally (Neidell, 2009; Ahumada amd Iturra, 2021; Zhang et al., 2022), with Asia being the most severely affected. Enhanced environmental monitoring has brought problems such as smog and sandstorms to the forefront of public awareness. Severe air pollution not only places added pressure on residents’ daily lives but has also become a major societal concern. As living standards rise, the public awareness of air pollution is also increasing. Firstly, air pollution directly affects people’s physical and mental health (Li et al., 2024; Lim et al., 2024), increases residents’ healthcare expenditures (Zhang and Mu, 2018; Huang and Lanz, 2018), and also reduces their sense of wellbeing (Levinson, 2012). Second, severe air pollution compromises the safety and quality of production, often reducing output or even halting operations, thereby hindering economic development (Feng et al., 2023). At a deeper level, chronic air pollution is detrimental to sustainable economic development, reflecting the “eco-deficit” inherent in conventional growth models that prioritize economic expansion over environmental sustainability (Vuong and Nguyen, 2025). This model can lead to “immiserizing growth,” where economic gains are undermined by severe environmental and social costs, such as the erosion of human capital through health deterioration and productivity losses (Vuong, 2021). With the increasing prominence of environmental problems brought about by traditional economic growth methods and the deepening of people’s awareness of healthy living, the migrant population no longer chooses to stay in a place solely on the basis of economic considerations (Li et al., 2023), and environmental factors are gradually being taken into important consideration (Chen et al., 2018). However, previous research on migrants’ location choices has often overlooked environmental factors such as air quality (Xu et al., 2022). Air quality is a core aspect of urban livability, and incorporating it into labor migration studies offers significant theoretical insights into understanding the workforce’s locational behaviors.

This paper explores the association of air pollution and the settlement intention of urban migrants in China, which is also an issue of considerable practical importance. First, China’s labor mobility has expanded markedly with economic development and reforms to the household registration (hukou) system. According to data from the 2021 Seventh National Population Census, the migrant population in China has increased by 70% over the past decade (Wu et al., 2022). Second, migrant flows bring human capital into different regions, acting as a vital engine of regional economic growth. By redistributing labor between areas with surplus and shortage, migration improves the overall allocation of labor and enhances efficiency (Sun et al., 2019). Allowing labor to move freely according to market mechanisms promotes balanced regional economic development, laying the groundwork for urban-rural integration and shared prosperity. However, real-world trends show that market-driven labor migration often concentrates workers in economically advanced regions (Shen et al., 2023), leading those areas to approach their population carrying capacity while less developed regions face a shortage of skilled personnel. This imbalance increases social pressures in economically advanced areas, undermines human capital accumulation in less developed regions, widens income gaps, and impedes coordinated urban-rural development. Consequently, understanding the factors that shape labor migration decisions and guiding these flows in a more balanced manner carry significant practical implications for economic growth and regional coordination (Liu et al., 2024b; Shang et al., 2022).

Complicating this dynamic in China is the household registration (hukou) system, a fundamental institution shaping migration patterns. In major cities, access to full social welfare, public education, and other local privileges is intrinsically tied to possessing a local hukou, which remains restricted for most migrants (Chen et al., 2018). This creates a scenario where migrants may be compelled to tolerate environmental disamenities like air pollution as a necessary trade-off for accessing superior economic opportunities—a phenomenon aligning with the theory of “compensating differentials” (Huang and Lanz, 2018). Consequently, the settlement intentions of China’s migrants are not merely a function of environmental and economic calculations (Li and Li, 2022) but are also profoundly shaped by these structural constraints. This paper contributes to this discussion by examining settlement intention net of these institutional pressures, focusing on the underlying environmental preferences that would likely be more fully expressed in a less restricted mobility context.

The marginal contributions of this paper, which set it apart from existing research, manifest in three key ways. First, most previous studies on the relationship between air pollution and labor have concentrated on how air pollution affects labor supply, for instance, one of the empirical researches has demonstrated that a 10 μg/m³ increase in PM₂.₅ concentration reduces farmers’ daily agricultural labor hours by 0.4 h (Ye et al., 2023). Numerous studies have further confirmed that rising PM₂.₅ levels exert a negative impact on labor supply duration (Yamada and Narita, 2025; Altansukh et al., 2025). But few studies consider the air quality as a determinant of migrant location decisions. Yet as people’s perceptions of quality of life continue to shift, air quality has become an increasingly critical factor in where migrants choose to settle, underscoring this study’s significant practical value. Second, most existing research adopts a macro perspective, using national-level aggregated data to measure population mobility, such as the number of employed persons used by Xiao (2016), national immigration data used by Fu and Gu (2017) and Xu and Sylwester (2016a), few studies have employed micro-level individual-level data to explore the differing impacts of air pollution on individuals with varying characteristics. Numerous studies have employed machine learning and other related computational methods to predict air quality. For example, Choudhary et al. (2023) and Kumar et al. (2024), both selected India as their study region, employed diverse computational algorithms to project sustained increases in future PM₂.₅ and hazardous gas concentrations. Their findings further indicate that crop residue burning, wildfire incidents, and elevated aerosol levels will exacerbate PM₂.₅ accumulation in the region (Kumar et al., 2024). These studies highlight that air quality is an critical societal issue in the future and focus on the factors that influence air quality. However, the most fundamental purpose of environmental governance is sustainable development. Since humans constantly inhale air, public health directly depends on air quality. Continued development of polluting industries will eventually undermine socioeconomic progress. Therefore, integrating environmental and human factors is both essential and practical (Hu et al., 2022; Yue et al., 2024). Both regional surveys and qie quality prediction studies fail to systematically integrate air pollution with human behavior and social development. Moreover, their reliance on marco-level data (Li et al., 2021) suffers from data opacity issues, preventing clear identification of population subgroups with varying susceptibility to air pollution. To fill these research gaps, this study uses individual-level microdata to explicity reveal the heterogeneous effects of air pollution on migrants’ settlement intentions. By leveraging micro-level data, this paper links the air quality and human behavior and provides a clearer portrayal of the heterogeneous effects of air pollution on migrants’ willingness to remain, thereby offering more targeted insights for cities seeking to retain human capital through environmental governance. Finally, few scholars have examined the mechanisms through which environmental factors drive population migration decisions. By exploring three pathways through which air pollution influences migrants’ willingness to stay, this paper enriches the current body of literature in this area.

The relationship between environmental issues and population mobility can be traced back to the “stress threshold” theory (Wolpert, 2010). This theory incorporates non-economic factors—such as environmental conditions—into the analytical framework of population mobility, positing that individuals make migration decisions in response to pressures or stress from their current place of residence. From the 1970s to the 1990s, theoretical models like the Harris-Todaro model (Harris, 1970), the stress-threshold residential mobility model (Speare, 1974), and the residential satisfaction–migration model emerged, further integrating non-economic factors into migration research. These developments not only enriched the field but also underscored the influence of environmental factors on migration (Slovic, 1987), marking the initial, albeit slow, phase of environmental migration research. Since the 1990s, research related to environment and population mobility has entered a period of rapid development, and the impact of air pollution on population mobility and migration has received the attention of many scholars (Germani et al., 2021; Xu and Sylwester, 2016b). A growing body of literature documents the relationship between environmental quality and migration, and frequently shows that changes in environmental quality can induce migration (Vilhelmson and Thulin, 2013). Air quality, as the main indicator of environmental pollution, has two effects: a push from the city of origin and a pull from the city of targeted inflow. Then, according to the “Push-Pull Theory” (Lee, 1966), air pollution is often seen as a negative factor in the inflow to the area, which may reduce the willingness of the migrant population to settle in the city.

Since the smog problem of China has been exposed in 2013, air quality has entered the field of domestic research, and the impact of air pollution on labour mobility and migration has attracted the attention of more scholars. Initially, some studies based on regional surverys provided preliminary evidence that air pollution could lead residents to consider moving away. For instance, Wang (2016) conducted a telephone survey in Beijing, and the data showed that environmental issues marked by smog had caused widespread public concern, with some individuals developing migration intention due to such pollution-related worries. Meanwhile, researches also found that improvements in Beijing’s air quality can enhance residents’ satisfaction with their living environment, thereby increasing their willingness to remain in this city. In addition, more and more quantitative studies used PM2.5 concertration as a measure of air quality (Chen et al., 2023) and found a negative relationship between urban PM₂.₅ concentration and residents’ settlement intention (Chu et al., 2015; Sun and Sun, 2018; Sun et al., 2019). Firstly, regarding health impacts, numerous studies have demonstrated that air pollution can lead to various acute and chronic diseases, thereby harming both physical and mental wellbeing (Hanna and Oliva, 2015). To avoid deteriorating health conditions, individuals may develop intentions or take actions to relocate (Deschênes et al., 2017). And then, people generally prefer not to work for extended periods in areas with severe air pollution (Masuda et al., 2021). Consequently, they are more inclined to reside in regions with better air quality to ensure sustained labor productivity and secure stable income. Therefore, this paper proposes Research Hypothesis 1:

Hypothesis 1

The air pollution is negatively associated with migrations’ settlement intention.

Assuming that Hypothesis 1 holds, we provide more detailed explantion of the possible mechanisms between air pollution and settlement intention. Research on air pollution and residents’ health spans multiple disciplines, including medicine and sociology. It is widely recognized that air pollution negatively impacts both physical and mental wellbeing, particularly by causing respiratory diseases (Chay and Greenstone, 2003; Knittel et al., 2016; Neidell, 2004; Tanaka, 2015). Prolonged exposure to contaminated air may increase mortality in infants and the elderly, who are more susceptible to the effects of ambient air pollution (Currie and Neidell, 2005; Jayachandran, 2009). Health, as a core component of human capital, directly influences labor capacity. At the same time, it serves as a vital personal asset. When migrants maintain good health, they tend to have a more positive mindset and greater vitality, enabling full participation in production activities and everyday life. This improved wellbeing enhances their overall satisfaction as residents and increases their intention to settle (Liu and Yu, 2020). Accordingly, this study posits that air pollution likely affects migrants’ settlement intention by undermining their health.

Hypothesis 2

Air pollution reduces migrants’ settlement intention by negatively affecting their health.

People take various measures to avoid the negative impacts of air pollution on their health status, such as reducing the amount of time they spend working outside (Neidell, 2009). From the perspective of labor supply, prior studies have shown that environmental pollution has a substantial negative effect on labor supply levels (Sheng et al., 2016). In particular, an increase in air pollution—especially rising PM₂.₅ concentrations—leads to a reduction in working hours (Zhao et al., 2021). As environmental awareness grows, the natural environment has become an increasingly significant consideration for labor migration decisions, with pollutant emissions exerting a “push effect” that drives different labor groups away from cities (Xiao, 2016). Labor mobility is most directly reflected in the willingness to settle in a particular location (Li, 2014). If high levels of air pollution reduce labor supply, shorter working hours lead to lower labor income, further fueling migration intentions and consequently diminishing migrants’ inclination to remain where they are (Cai, 2018). Therefore, this paper proposes Research Hypothesis 3:

Hypothesis 3

Air pollution reduces migrants’ settlement intention by decreasing their working hours and income.

As a negative environmental externality, air pollution adversely affects human health, life quality and social economic (Chang et al., 2024; Liu M. et al., 2024). Consequently, there is currently a significant amount of research exploring how to improve air quality. Society’s governance of the environment includes enacting environmental laws and regulations, implementing pollution taxes (Li and Ramanathan, 2018), and controlling pollution emission rights to encourage companies to invest in pollution control (Zhu, 2015). These policy measures may be effective in protecting the environment. Compared to policy interventions, urban greening represents a more direct mitigation strategy. Vegetation effectively filters airborne pollutants and reduces ambient PM₂.₅ concentrations (Akaraci et al., 2022). As critical ecological infrastructure, urban green spaces can not only directly improve air quality but also mitigate the negative impact of pollution on residents’ quality of life. Therefore, this study will further evaluate whether utban green coverage can effectively mitigate the impact of air pollution on residents’ settlement intention.

Hypothesis 4

Urban green coverage can mitigate the negative correlation between the air pollution and migrants’ settlement intention.

By reviewing the existing literature, we find that environmental factors have garnered substantial scholarly attention in the context of labor mobility. Although previous research has accumulated and evolved over time, several gaps remain. First, most studies examine how air pollution affects labor supply—whether in terms of hours worked or overall labor availability—without considering air quality as a key determinant in migrants’ locational choices. Yet as lifestyle perceptions continue to shift, air quality has gradually emerged as an important consideration for migrants deciding where to settle. Second, domestic research on air pollution and population mobility has yet to form a cohesive analytical framework. Most existing studies adopt a macro-level perspective, rarely investigating how air pollution may differentially affect individuals based on distinct characteristics. In response to these limitations, this paper employs both macro- and micro-level datasets for regression analysis, drawing on the relatively mature analytical methods established by earlier studies. We conduct a stepwise test of the stated hypotheses and give particular attention to the relationship between air pollution and migrants’ settlement intentions. Through a more comprehensive empirical approach, this study clarifies the mechanisms by which air pollution shapes labor mobility decisions, offering more practical insights for cities seeking to retain human capital through effective environmental management. We use Figure 1 to generalize all the hypotheses.

The empirical analyses presented earlier have shown that urban air pollution has a significantly negative effect on the willingness of the migrant population to settle, with clear heterogeneity in this relationship. The underlying mechanisms driving this effect warrant further exploration. On one hand, we suggest that air pollution directly impacts the health of migrants, thereby reducing their willingness to settle. On the other hand, long-term exposure to polluted environments can harm physical health, particularly by increasing the incidence of respiratory diseases. This, in turn, may reduce the labor supply (Hanna and Oliva, 2015). A reduction in labor supply could, in turn, lower potential earnings. Therefore, this study posits that the impact of air pollution on the willingness of the migrant population to settle may also follow the logic of the following causal chains “Air Pollution → Reduced Labor Supply → Decreased the settlement intention” and “Air Pollution → Reduced Labor Income → Decreased the settlement intention of urban migrants”. In summary, this study introduces the health status of migrants, average weekly working hours, and average monthly household income as mediating variables to explore the mechanisms through which air quality affects the settlement intention of urban migrants.

The empirical analyses presented earlier have shown that air pollution has a significantly negative effect on the settlement intention of urban migrants, with clear heterogeneity in this relationship. The underlying mechanisms driving this effect warrant further exploration. On one hand, we suggest that air pollution directly impacts the health of migrants, thereby reducing their willingness to settle. On the other hand, long-term exposure to polluted environments can harm physical health, particularly by increasing the incidence of respiratory diseases. This, in turn, may reduce the labor supply (Hanna and Oliva, 2015). A reduction in labor supply could, in turn, lower potential earnings. Therefore, this study posits that the impact of air pollution on the willingness of the migrant population to settle may also follow the logic of the following causal chains “Air Pollution → Reduced Labor Supply → Decreased Willingness to Settle” and “Air Pollution → Reduced Labor Income → Decreased Willingness to Settle” In summary, this study introduces the health status of migrants, average weekly working hours, and average monthly household income as mediating variables to explore the mechanisms through which urban air quality affects the settlement intention of urban migrants.

According to the KHB decomposition results (Table 10), both self-assessed and externally assessed health statuses exhibit significant total effects, direct effects, and indirect effects at the 1% significance level. After controlling for health status, the result suggests that air pollution leads to poorer health, which in turn reduces the willingness to settle. This finding indicates that health status partially mediates the relationship between air pollution and settlement intentions, highlighting the importance of considering health outcomes when examining the effects of environmental factors on migration decisions.

To explore whether air pollution influences the settlement intention of urban migrants by reducing household income and weekly working hours, this study extracts data on household average monthly income and respondents’ average weekly working hours from the survey. The KHB decomposition results in Table 11 reveal that air pollution continues to have a significantly negative impact on the willingness of migrants to settle, with total effects, direct effects, and indirect effects all being significant at the 1% level.

Firstly, with regard to household average monthly income, the indirect effect is −0.0593, which is significant at the 1% level. This indicates that air pollution reduces household average monthly income, thereby decreasing the willingness to settle. This could be due to the increased medical expenditures in environments with poor air quality, which lowers household income. Moreover, air pollution may lead to reduced productivity and absenteeism, further impacting household income.

In addition, the indirect effect of average weekly working hours is also significantly negative at the 1% level. This suggests that air pollution can reduce the willingness to settle by decreasing the average weekly working hours of individuals. Health plays a crucial role in overall wellbeing; good physical and mental health enriches daily life, boosts enthusiasm for living, and provides greater motivation and capacity for longer working hours. Poor air quality can lead to various health issues, such as respiratory problems, fatigue, and reduced cognitive function, which may limit an individual’s ability to work long hours. Furthermore, there is a strong link between working hours and income, as reduced working hours often translate to lower earnings.

These findings highlight the multifaceted nature of the relationship between air pollution and settlement intentions, with both household income and working hours serving as important mediating factors. Policymakers and urban planners should consider the broader economic and health implications of air pollution when developing strategies to attract and retain migrant populations in cities.

In the above analysis, we used a mediation effect to examine the mechanism of air pollution’s impact on the migrants’ settlement intention. But how can the adverse effects of air pollution on migrants’ settlement intentions be mitigated? Maybe this is an more important challenge for policymakers. Therefore, we will continue to use Equation 2 to study the moderating effect of urban green coverage. s e t t l e i , j = α 0 + β 1 A Q I j + β 2 G r e e n j + β 3 A Q I j * G r e e n j + β 4 X i + β 5 C j + ε i (2)

As the result shown in Table 12, after adding the interaction term in column (2), for every 100-unit increase in AQI, the urban migrants’ settlement intention decreases by 6.69%. Compared with column (1), the negative impact of air pollution on the settlement intention of urban migrants has been reduced. Moreover, the coefficient of the interaction term AQI*Green is positive and significant at the 1% significance level, confirming that urban green coverage can effectively mitigate the negative impact of air pollution on the urban migrants’ settlement intention. In other words, the higher the urban green coverage, the more it can mitigate the negative impact of air pollution on the settlement intention of urban migrants.