Niloz Das

Abstract
Although discrimination has been validated to be negatively related to mental health, little is known about the effect of hukou-based discrimination by teachers on depression among migrant adolescents in China. The mediating and moderating mechanisms underlying this association are also unknown. Based on a nationally representative sample of migrant adolescents, this study examined whether school engagement mediated the association between teacher discrimination and depression, and whether the direct and mediating effects were moderated by poverty. Our sample comprised 2041 migrant adolescents (46.2% female) from the first two waves of the China Education Panel Survey (CEPS). The results indicated that teacher discrimination (T1) was positively associated with depression (T2). Emotional engagement with school (T1) rather than cognitive engagement with school (T1) partially mediated this association. Moreover, poverty status moderated the direct association between teacher discrimination and migrant adolescents’ depression as well as the indirect relationship via emotional school engagement. Specifically, the direct and indirect effects were stronger for migrant adolescents living in poverty than they were for their non-impoverished counterparts. Contributions and implications of this study are discussed.

Introduction
According to the National Committee on Family Planning (2013), there were about 35.8 million internal migrant children who moved together with their parents to urban cities in Mainland China. Under China's hukou (household registration) system, each citizen is assigned a rural or urban hukou based on his/her birthplace. At the same time, social welfare and citizenship are largely connected to hukou status. City-based education, health care, and other social services are linked exclusively to the urban hukou (Jia et al., 2017). Thus, compared to local urban residents, migrant students without a local hukou are more disadvantaged due to institutional constraints (Wang et al., 2018). Previous studies also indicated that migrants’ mental health status is worse than that of their peers in host cities (Wang and Zou, 2010; Yuan et al., 2012). One of the risk factors contributing to the maladjustment of migrants is discrimination, which refers to the unfair treatment experienced by an individual or group related to specific characteristics such as gender and ethnicity (Williams et al., 1997). In the case of Chinese migrants, discrimination may be due to having no resident identity as local urban citizens in the host city (Liu and Zhao, 2016).

School is a vital context for adolescents’ socialization (Benner and Graham, 2013; Chavous et al., 2008), and discrimination by teachers is common in the school setting (Greene et al., 2006; Ng, 2010). International studies have suggested that ethnic minorities often experience race-based teacher discrimination (Chavous et al., 2008). Likewise, Chinese migrant students are subjected to teacher discrimination due to their non-local resident status (Wang et al., 2018; Wang and Jiang, 2016). While previous research has indicated that discrimination constitutes a potential threat to migrant adolescents’ psychological well-being (Jia et al., 2017; Liu and Zhao, 2016), few of these studies focused specifically on teacher discrimination, and relatively little is known about the mediating and moderating mechanisms underlying this relationship. Thus, the purpose of this study is to examine how teacher discrimination influences the mental health of Chinese migrant adolescents. In addition, we aim to explore the mediating effect of school engagement and the moderating effect of poverty status on the relationship between teacher discrimination and depression among migrant adolescents.

Previous studies have consistently demonstrated that the experience of discrimination has detrimental effects on the mental health of vulnerable groups (Carter et al., 2017; Flores et al., 2010; Schmitt et al., 2014; Straiton et al., 2019; Tummala-Narra and Claudius, 2013). In the case of Chinese migrant children, discrimination was validated to be negatively associated with their psychological adjustment (Chen et al., 2014; Wang and Mesman, 2015). In particular, empirical studies revealed that discrimination induced higher levels of psychological distress, including depression, anxiety, and loneliness (Xing et al., 2011; Wang et al., 2018), and led to lower levels of psychological well-being as reflected in a reduced level of subjective well-being and life satisfaction (Jia et al., 2017;