Abstract: This study focuses on the causal relationship between middle school students'participation in cram school and their emotional well-being. Our analysis is based on Chinese Education Panel Survey data (CEPS 2013-2015). We construct instrumental variables and introduce lagged variables to mitigate possible endogeneity problems. The major findings are as follows:Firstly,the participation of socio-economically disadvantaged students in cram school has significantly exacerbated their negative emotions. Students with advantaged family socioeconomic status (SES) have shown better ability in emotional regulation,and they are more likely to be psychologically immune to specific negative emotions. Secondly,we explore the class heterogeneity in the aspect of emotional regulation ability. Specifically,we propose a preliminary theoretical framework based on typology of parenting styles and related empirical findings. We speculate that parents from different social background may respond differently to their children's negative emotions,while there may also be intergroup differences in children's own emotional regulation ability. Empirically,we examine the class differences in the performance of emotional regulation of the students in cram school,and apply the counterfactual simulation approach to further illustrate the association between the group difference in emotional regulation and the group heterogeneity of the depressive effects from cram school participation. The finding provides supportive evidences for our theoretical framework. In sum,our study is helpful to better understand the implication of emotional health inequality that may derive from the shadow education system.

Key words: social stratification, cram school, negative emotion, causal inference, instrumental variable