How Early Morning Classes Change Academic Trajectories: Evidence From a Natural Experiment
利用课程时间随机分配的自然实验，发现早课降低学生课程成绩和未来STEM课程选修概率，导致同一学院内专业选择减少29%，低薪专业选择增加21%。
ABSTRACT Using a natural experiment which randomized class times to students, this study reveals that enrolling in early morning classes lowers students’ course grades and the likelihood of future STEM course enrollment. There is a 29% reduction in pursuing the major within the same college and a 21% rise in choosing a low‐earning major, predominantly influenced by early morning STEM classes. To understand the mechanism, I conducted a survey of undergraduate students enrolled in an introductory course, some of whom were assigned to a 7:30 a.m. section. I find evidence of a decrease in human capital accumulation and learning quality for early morning sections.