How does the impact of the COVID-19 state of emergency change? An analysis of preventive behaviors and mental health using panel data in Japan

Abstract

This study applies the difference-in-difference method on panel data collected from internet surveys to investigate changes in the preventive behaviors and mental health of individuals as influenced by the COVID-19 state of emergency declaration between March and June 2020. The key findings are: (1) The declaration led people to exhibit preventive behaviors but also generated negative emotions; (2) Such behaviors persisted even after deregulation of the state of emergency; (3) Making the declaration early (vs. late) had a larger effect on preventive behavior, with the gap between residents' behaviors for areas that made early vs. late declarations persisting after the deregulation; and (4) The effects on mental health diminished during the state of emergency and disappeared after its deregulation.

Keywords: COVID-19; Mental health; Preventive behavior; State of emergency declaration.

Fig. 1

March 1 to June 30, 2020: Timing of surveys and state of emergency declaration, and daily changes in the number of people infected by COVID-19 for each group Note: The long dash lines indicate the date the surveys were conducted. The first, second, third, fourth, and fifth times were conducted on March 10, March 27, April 10, May 8, and June 12, respectively. The thick solid line between the second and third times of the survey indicate the date of the emergency declaration for seven prefectures on April 7, and the long, thick dash line indicates the date of the declaration throughout Japan (47 prefectures) on April 16. The thick solid line between the fourth and fifth times of the survey indicates the date of deregulation of the state of emergency throughout Japan on May 25.

Fig. 2

Comparison of the mean values of COVID-19 infection case per 100,000 for each group. Note: We use the number of COVID-19 infection cases per 100,000 as the proxy for the degree of spread of COVID-19. We illustrated Fig. 2 using proxy values from April 1 to April 7, 2020. Error bars represent 95% confidence intervals. The treatment group consisted of Tokyo, Kanagawa, Saitama, Chiba, Osaka, Hyogo, and Fukuoka prefectures. Control group consists of Hokkaido, Aichi prefectures.

Fig. 3

Location of treatment and control groups in Japan. Notes: Prefectures shared black are the treatment group, while prefectures shared grey are the control group.

Fig. 4

Changes in the mean values of preventive behavior variables Note: The solid line indicates the treatment group, while the dashed line denotes the control group.

Fig. 5

Changes in the mean values of mental health variables Note: The solid line indicates the treatment group, whereas the dashed line denotes the control group.

Fig. A1

Comparison of the mean values of COVID-19 infection case per 100,000 for each group. Alternative control group is used. Note: We use the number of COVID-19 infection cases per 100,000 people as a proxy for the degree of spread of COVID-19. We illustrated Fig. A1 using proxy values from April 1 to April 7, 2020. Error bars represent 95% confidence intervals. Comparison of the mean number of people infected with COVID-19 in each group Treatment group consists of Tokyo, Kanagawa, Saitama, Chiba, Osaka, Hyogo, Fukuoka. The control group consisted of Hokkaido, Aichi, Kyoto, Ibaragi, Gifu, and Ishikawa prefectures.

Fig. A2

Changes in the mean values of proxy variables for preventive behavior. Note: The solid line indicates the treatment group, whereas the dashed line denotes the control group. The control group consisted of Hokkaido, Aichi, Kyoto, Gifu, Ishikawa, and Ibaragi. Fig. A2 corresponds to comprehensive preventive behavior in Fig. 4.

Fig. A3

Changes in the mean values of proxy variables for meatal health. Note: The solid line indicates the treatment group, whereas the dashed line denotes the control group. The control group consisted of Hokkaido, Aichi, Kyoto, Gifu, Ishikawa, and Ibaragi. The Fig. A2 correspond to Mental health in Fig. 5.