1970. One particularly clear case is that of Japan: with a savings rate close to 15 percent a year and a growth rate barely above 2 percent, it is hardly surprising that Japan has over the long run accumulated a capital stock worth six to seven years of national income. This is an automatic consequence of the dynamic law of accumulation, β = s/g. Similarly, it is not surprising that the United States, which saves much less than Japan and is growing faster, has a significantly lower capital / income ratio.
