Rapidly reduced fertility rate and working-age population In the aftermath of World War II, Japan enjoyed a period of so-called “population dividend,” which helped produce higher economic growth. This refers to a period when the total dependency ratio (defined as the youth and elderly population over the working-age population) decreases drastically with a decline in the number of children.
In Japan, the total population rose rapidly in the second half of the 1940s with the first postwar baby boom in 1947–49; this was followed by the second-generation baby boom in 1971–74 (Chart 1).