This study estimates the average treatment effect on the risk of infection for outings, face-to-face contact, and holiday travel during the Covid-19 pandemic. We use panel data from a survey conducted every three months from October 2020 for one year with registrants of an Internet survey company, with inverse probability weighting estimation. The results of the analysis show that holiday travel and face-to-face contact, although not high-risk, reveal a certain level of infection risk depending on the state of spread at the time of each survey, and this risk varies according to individual attributes, such as gender, age, and region of residence. However, even during the Covid-19 pandemic, simple outings did not increase the infection risk, which can be attributed to the declaration of a state of emergency, a moderate NPI implemented in Japanʼs urban areas. Validating a subsample of vaccinated and unvaccinated individuals indicates that vaccination may have a significant effect on reducing the risk of face-to-face contact and holiday travel, thereby reducing the spread of the infection.
