According to the study by Poterba (2001), this positive association can also be observed with respect to the level of asset prices (measured by the dividendprice ratio), although the relationship between the rates of return on various assets and the working-age population share is ambiguous.3 Several experts in demography argue that economic miracles such as those in Asia and Ireland are simply due to the rise in the share of the working-age population.
In the case of Japan, the working-age population ratio increased from about 60 percent to about 70 percent in the high-growth era (from 1955 to 1970). In China, the working-age population ratio increased from 55 percent in 1975 to 60 percent in the early 2000s, and is expected to surpass 70 percent by 2010.