旅行与新冠病毒感染风险：依据第三次感染高峰之前的个体数据的分析

In this study, we estimated the average treatment effect (ATE and ATT) of holiday travel on the risk of new coronavirus infections using propensity score matching and inverse probability weighting estimation. The analysis is based on individual data from an internet survey (the first panel survey) conducted from October 27 to November 6, 2020, among registrants of an internet research company with 16,642 valid responses. The results of the analysis reaffirmed the conclusion of previous studies that travel has a significant impact on the risk of developing infectious symptoms and the risk of coronavirus infections. Furthermore, analysis by attribute group showed that the risk of infection was higher for those who were younger, male, lived in an area where infection was spreading, and had more direct contact with friends, while for those who were older, female, lived in a non-infected area, and had less direct contact with friends, travel posed a relatively low or insignificant risk.