State of Emergency and Human Mobility during the COVID-19 Pandemic in Japan
Authors: Okamoto Shohei 
Published: June 2021

AbstractBackgroundTo help control the spread of the coronavirus disease 2019 (COVID-19), the Japanese government declared a state of emergency (SoE) four times. However, these were less stringent than other nations. It has not been assessed whether soft containment policies were sufficiently effective in promoting social distancing or reducing human contact.MethodsUtilising the Google mobility index to assess social distancing behaviour in all Japanese prefectures between 15 February 2020 and 21 September 2021, mobility changes were assessed by an interrupted time-series analysis after adjusting for seasonality and various prefecture-specific fixed-effects and distinguishing potential heterogeneity across multiple SoEs and time passed after the declaration.ResultsThe mobility index for retail and recreation showed an immediate decline after the declaration of the SoE by 7.94 percent-points (95%CI: -8.77 to -7.12) and a further decline after the initial period (beta: -1.27 95%CI: -1.43 to -1.11), but gradually increased by 0.03 percent-points (95%CI: 0.02 – 0.03). This trend was similar for mobilities in other places. Among the four SoEs, the overall declines in human mobility outside the home in the third and fourth SoE were the least significant, suggesting that people were less compliant with social distancing measures during these periods.ConclusionAlthough less stringent government responses to the pandemic may help promote social distancing by controlling human mobilities outside the home, their effectiveness may decrease if these interventions are repeated and enforced for extended periods, distorting one’s health belief by heuristics biases. By combining these with other measures (i.e. risk-communication strategies), even mild containment and closure policies can be effective in curbing the spread of the virus.What is already known?Human mobility, in terms of tracing social distancing and human contact in places such as shops, restaurants, and workplaces, was reported to be a useful indicator for predicting COVID-19 outbreaks.Containment and closure policies, such as country lockdowns and a State of Emergency (SoE) declarations, effectively reduce human mobility.What are the new findings?This study first evaluated if longer and repeated SoEs were effective to reduce human mobility.The findings from this study suggests that although less stringent government responses to the pandemic may help promote social distancing by controlling human mobilities outside the home, their effectiveness decreases if these interventions are repeated and enforced for extended periods.What do the new findings imply?While less stringent government responses to the pandemic are effective in promoting social distancing by controlling human mobilities outside the home, their effectiveness may decrease if similar interventions are repeated for extended periods of time.However, by combining these with other measures such as risk-communication strategies, even less costly interventions such as mild containment and closure policies can be effective in curbing the spread of the COVID-19 virus.Research in contextEvidence before this studyIt has been shown that human mobility, in terms of tracing social distancing and human contact in places such as shops, restaurants, and workplaces, was reported to be a useful indicator for predicting COVID-19 outbreaks. Also, previous studies have shown that containment and closure policies, such as country lockdowns and a State of Emergency (SoE) declarations, effectively reduce human mobility. However, it is not explicitly known whether longer and repeated ‘alerts’ requesting citizens to avoid nonessential activities with risk communication strategies are equally effective.Added-value of this studyThis study first evaluated if longer and repeated SoEs were effective to reduce human mobility, suggesting three main findings. First, individuals engage in social distancing behaviours during the initial periods of the SoE but become less compliant as time passes. Second, when mobility changes during each SoE were distinguished, overall declines in mobilities outside the home and increases in stay-at-home time were less obvious during the succeeding SoEs. Third, under the stringent government responses to the pandemic and decline in mobilities, the consumption level—especially for activities outside the home— sharply declined, suggesting that strong public interventions may worsen the economy.Implications of all the available evidenceWhile less stringent government responses to the pandemic are effective in promoting social distancing by controlling human mobilities outside the home, their effectiveness may decrease if similar interventions are repeated for extended periods of time. However, by combining these with other measures such as risk-communication strategies, even less costly interventions such as mild containment and closure policies can be effective in curbing the spread of the COVID-19 virus.