@techreport{oai:ir.ide.go.jp:00051876,
 author = {Souknilanh, Keola and Hayakawa, Kazunobu},
 month = {Sep},
 note = {application/pdf, IDP000800_001.pdf, In this study, we empirically investigate how much human economic and social activity was decreased by the implementation of lockdown policy during the coronavirus disease 2019 (COVID-19) pandemic. We measure the magnitude of human activity using nitrogen oxide (NOx) emissions. Our observations include daily NOx emissions in 173 countries between January 1 and July 31, 2020. Our findings can be summarized as follows. Lockdown policy significantly decreased NOx emissions in low-income countries during the policy as well as post-policy periods. In high-income countries, however, NOx emissions increased during both periods. It was also found that the absolute impact of the lockdown policy was larger during the post-policy period than during the policy period. While the stay-at-home policy reduced NOx emissions, we did not discover robust differences between regions in its effect.},
 title = {Does lockdown policy reduce human activity?},
 year = {2020}
}