This dissertation is mainly focusing on an economic evaluation of a childhood obesity intervention program, after school physical activities and a nationwide social health care program. The analysis is conducted within three main essays. The purpose of the first essay is to estimate peer effects on third grade students’ BMI and to investigate the social and physiological explanations for such effects. The BMI of students from a childhood obesity intervention program (N=573) is used to assess peer effects on students’ BMI by identification of endogenous social effects. We apply IV regression to account for this endogenous effects. Strong peer effects are found for the overall sample, females and males (p<.1). However, when classifying students into improvement versus non-improvement groups, the peer effect is only found among females categorized in the improvement group (B=1.472) and males in the non-improvement group (B= 1.176). Thus in general, peer effects are found for students aged 8-11, with sex differences in the psychological and social behavioral motivations.
In the second essay, we exploit the data from the Trends in International Mathematics and Science Study (TIMSS) 2011 to evaluate the effect of playing after school on academic performance by using a propensity score matching approach. We highlight that in addition to intrinsic characteristics of students, the extent to which after school activities affect academic performance depends on extrinsic factors such as parental involvement. In order to capture the heterogeneous effects of playing after school, we analyze the effect by separating the overall sample according to whether parents check their children’s homework and set specific times for after school homework. We further uncover heterogeneous effects of playing after school for different levels of parental involvement and supervision. The results show that playing after school significantly increases math and science test scores of students by 7.9 points and 4.2 points respectively. Moreover, this positive effect is stronger among students with greater parental involvement and supervision, but weaker or nonexistent among students with less parental involvement and supervision.
The third essay fills the gap in the literature by examining the long-term causal effects of Medicaid enrollment on high school and college completion through a regression discontinuity design that exploits an eligibility discontinuity created by the Medicaid expansion of 1990. Using the American Community Survey data, we present evidence that Medicaid enrollment decreased high school completion rates by 3.6 percentage points (using local linear regression and IK bandwidth selector). However, we find little evidence of adverse impact of Medicaid on college completion. We also find heterogeneous effects by race/ethnicity. While Medicaid has no significant impact on educational achievement of blacks or Asian, Hispanics are negatively affected by Medicaid on both high school and college completion
