The influence of demography on economic growth should not be underestimated. Our research shows that demography contributed to a tailwind in Phase II and will likely contribute to a headwind in Phase III. Figure 3 presents the results for the countries of the G-8 and the BRICs. We forecast growth in Real Per Capita GDP (holding everything else constant) for every five-year interval between 1950 and 2050, based on the demographic linkages observed in the 1950–2010 data spanning 22 countries. These are not "normal" GDP growth rates, they are abnormal GDP growth rates, reflecting the impact of a demographic tailwind or headwind.
Japan displays the most manifest effects. The Japanese "economic miracle" of the 1960s to the 1980s got a terrific lift from demography. The birthrate plunged, so that support ratios associated with legions of children disappeared, and the support ratios associated with legions of senior citizens did not really outstrip the decline in the roster of children until the 1990s. Their demographic "dividend" may have peaked at approximately 3% per year, relative to the average demographic profile of the century from 1950 to 2050.
Now, the youngsters of the late 1940s and early 1950s are approaching retirement, and the baby bust from about 1980 onward is delivering a continually shrinking roster of new entrants to the labor force. With relatively few young workers to take the place of retiring boomers, Japan's prospective demographic headwind may be greater than 2% per year. A transition from a 3% tailwind to a 2% headwind is shocking: it suggests a 5 percentage point drop in normal real per capita GDP growth rates from the heady growth of the 1960s to the 1980s. Even if changes in policies and entitlements can halve these figures, it's a formidable headwind.