摘要:Furceri and Karras(2007, 2008) insisted that smaller countries are subject to more volatile business cycles than larger countries and country size really matters using international data from 1960 to 2000. In this paper, we calculate welfare benefit from doubled country size in Japan, US and OECD average on 2007. For calculating welfare benefit, we use welfare cost of business cycle approach following Obstfeld(1994), and we examine the welfare consequences of their conclusion. Our simple calculations shows that even if Fuerci and Karras(2007, 2008) is right, welfare benefit from country size is small, less than 1% in terms of consumption. Our conclusion suggests that, as long as focusing on only business cycle, population size is not important in terms of welfare, contrary to Furceri and Karras(2007, 2008). However, for example, note that we focus only on the effect of population size on business cycle and we neglect the effect of population size on growth rate of macroeconomy, though some studies recognize it. In other words, our conclusion in this paper is only one suggestion about welfare consequence of population size, particularly focused on and limited to the effect of severity of business cycle. Further researches about welfare consequence of population size (country size) are needed