The elderly have too few young people to rely on to pay their benefits.

From the WSJ’s Notable & Quotable: Ben Wattenberg:

Never-born babies are the root cause of the “social deficit” that plagues nations across the world and threatens to break the bank in many. When a very large cohort of population (a “baby boom”) is followed by a very small cohort (a “birth dearth”), there will be relatively few working-age people to underwrite the benefits of the many seniors who have paid into national retirement systems, such as Social Security and Medicare.

On the surface there are two unappetizing ways to deal with this: a sharp cut in benefits or massive deficits. But at the heart of the problem are birth rates (the number of births per 1,000 people per year) and total fertility rates (the average number of children born to a woman over her lifetime) that have fallen sharply all over the world. . . .

The heated rhetoric of the 1960s and ’70s warning of an impending “population explosion” [contributed] to declining birth and fertility rates. Young people everywhere heard this message over and over and wondered whether they should bring another hungry mouth into a world of runaway population and declining resources. Of course, resources weren’t declining and population growth was not out of control.

Today, potential parents should hear a new message—which can and should be delivered widely, and by celebrities as well as politicians: The real danger for the future is too few births.