What Causes Fertility Decline? Answers From Two Demographers . . . And a New Mystery, Solved!

• Post by: Allan C. Carlson
• October 6, 2022

A defining feature of the United States of America, a clear and long-standing mark of this nation’s “exceptionalism,” recently took a harsh blow. The U.S. Census Bureau reported in 2021 that annual population growth had fallen to near zero, the lowest figure ever recorded in the nation’s history. As recently as 2016, the nation grew by 2.3 million persons; in 2021, by only 393,000, near one-tenth of one percent. A rise in the death rate and a lull in immigration, both attributed to COVID-19, were part of the cause. However, the primary reason for this end to growth was another fall in the American birth rate, to a total fertility rate of 1.64 average lifetime births per woman.1 After 250 years of robust openness to children, the United States is now in the same mix with the demographically challenged lands of Europe. This development also raises to new prominence a key question: What causes fertility decline? Analysts have wrestled with this question ever since the birth rate began to fall in France during the middle decades of the 19th century, a development which then spread to other lands in Europe, the Americas, Australia-New Zealand, and then to East Asia, and beyond. The arguments and conclusions of two demographers—Ron Lesthaeghe and John C. Caldwell—are especially helpful in sorting out the issues.   Lesthaeghe and Secularization Born and educated in Belgium, Lesthaeghe’s doctoral dissertation appeared in English translation in 1977, with the title The Decline of Belgian Fertility, 1800-1970. In exhaustive detail, he compares and contrasts trends in the birth rates and related vital statistics among the rural regions and cities of this comparatively small land. As anticipated, Lesthaeghe demonstrates the link between the emergence of industrial capitalism, a more frenetic urbanism, and the turn of both men and women to employment outside the home with fewer children born per couple. As he summarizes, “the metamorphosis of the