So just how big of an effect will a smaller workforce have on the economy? In 2011, Harvard University’s Program on the Global Demography of Aging published a paper that tried to understand this question. Logic suggests that a workforce that has to support fewer nonworking individuals will be wealthier overall, and the study bears out that hypothesis. In the paper, economists David E. Bloom, David Canning and Günther Fink estimated how high-income countries (most of which have aging populations) would have grown from the 1960 to 2005 period if they had experienced population growth similar to the projections for 2005 to 2050. According to the report, if a high-income country like the U.S. had a per-person income of $10,000 in 1960, that income grew to $34,600 under the population growth we actually experienced. On the other hand, if the 1960 to 2005 period experienced the sort of population growth that we’re expected to see through 2050, that income would have grown only to $25,500.

This huge difference underscores how important population growth and workforce participation is to a country’s economy. If there are more people working in a country, and if a higher percentage of those people are productive, the whole country will be richer. (This is one reason why economists tend to support policies that increase immigration.)