Due to the suspension of in-person classes in response to the COVID-19 pandemic, students at universities with earlier spring breaks traveled and returned to campus while those with later spring breaks largely did not. We use variation in academic calendars to study how travel affected the evolution of COVID-19 cases and mortality. Estimates imply that counties with more early spring break students had a higher growth rate of cases than counties with fewer early spring break students. The increase in case growth rates peaked two weeks after spring break. Effects are larger for universities with students more likely to travel through airports, to New York City, and to popular Florida destinations. Consistent with secondary spread to more vulnerable populations, we find a delayed increase in mortality growth rates. Lastly, we present evidence that viral infection transmission due to college student travel also occurred prior to the COVID-19 pandemic.

由于因应新冠肺炎 (COVID-19) 大流行而暂停面授课程，春假较早的大学的学生纷纷返回校园，而春假较晚的大学则大多没有返校。我们利用学术日历的变化来研究旅行如何影响 COVID-19 病例和死亡率的演变。据估计，提前春假学生较多的县的病例增长率高于提前春假学生较少的县。病例增长率在春假后两周达到顶峰。对于大学来说，影响更大，因为学生更有可能通过机场前往纽约市和佛罗里达州的热门目的地。与向更脆弱人群的二次传播相一致，我们发现死亡率增长率出现延迟上升。最后，