Over a longer time frame, teenage pregnancy may not correlate with poverty and welfare dependency at all. Duke University economist V. Joseph Hotz found in a 2004 study that by age 35, former teen moms had earned more in income, paid more in taxes, were substantially less likely to live in poverty, and collected less in public assistance than similarly situated women who waited until their 20s to have babies.

The bigger economic picture is that more people means more economic activity, from the first ultrasound, to the birth, to the costs of raising the child, to the child entering the labor force, at which point she will buy a home, pay taxes, save for retirement, etc. A larger population requires more infrastructure — homes, shops, roads, ports, schools, hospitals — the building of which creates jobs and stimulates the economy over a lifetime.

Economic growth is strongly correlated with population growth. And simply put, the earlier each generation goes forth and multiplies, the earlier the wider economy receives these benefits. Keeping up the birth rate has fallen to older mothers, but U.S. birth rates generally are falling, and are now lower than Russia’s, a country once famed for its low birth rate.