・Countries covered: Japan, G7 countries, Sweden, Australia, and Asian countries
・Quarterly GDP: Japan, United States, United Kingdom, Germany, Canada, France, Italy, Sweden, Australia, South Korea, India, China, Indonesia, Singapore, Hong Kong, Malaysia, Thailand, Philippines
・Monthly GDP: Countries with monthly indexes among countries with quarterly GDP (Japan, United States, United Kingdom, Germany, Canada, France, Italy, Sweden, Australia, South Korea, India)
・To compare GDP trends in developed countries and between Asian countries and Japan
・Source of the data
・Quarterly GDP (ex-Japan): Global Economic Monitor, The World Bank
・Quarterly GDP (Japan): "GDP (expenditure side) and demand items" (Cabinet Office)(https://www.esri.cao.go.jp/jp/sna/data/data_list/sokuhou/files/2022/qe221/gdemenuja.html)(used on May 18, 2022)
・Monthly GDP index: OECD (2022), Composite Leading Indicators, https://stats.oecd.org/Index.aspx?DataSetCode=MEI_CLI (last cited: 2022/05/07).
・Trend lines were created independently based on the above data.
・Coronavirus death numbers: WHO COVID-19 Dashboard. Geneva: World Health Organization, 2020. Available online: https://covid19.who.int/ (last cited: Feb. 19, 2022). “Dong E, Du H, Gardner L. An interactive web-based dashboard to track COVID-19 in real time. Lancet Inf Dis. 20 (5): 533-534. doi: 10.1016/S 1473-3099 (20) 30120-1 ”
・Population (2019 statistics used): United Nations, Department of Economic and Social Affairs, Population Division (2019). World Population Prospects 2019, Online Edition. Rev. 1.
・Trend creation method
・Quarterly GDP: A linear regression model of time and quarterly GDP is created from the values for the 9 years (36 periods) from 2011 to 2019 to calculate the deviation from quarterly GDP in 2020 and beyond.
・Monthly GDP: The quarterly GDP in 2015 is set at 100 to form the monthly GDP from January 2016 to December 2019 using the Index of Monthly GDP Trends (OECD, Composite Leading Indicators). Created a linear regression model of time and monthly GDP. We also determined the deviation between the value of quarterly GDP from 2016 to 2019 and the value of monthly GDP for the same period formed, then created a linear regression model of that value and time. The average of the two models is used as the trend, and the deviation from the monthly GDP after 2020 is calculated using the same method as before. The reason for the complexity of the method used to create the monthly GDP trend is that the OECD, Composite Leading Indicators is used as the indicator for monthly GDP instead of monetary values, which requires estimating monetary values based on quarterly GDP, and the method used to estimate the trend is considered optimal in comparison with past GDP trends.