MPIDR Working Paper

Revisiting the J-shape: human development and fertility in the United States

MPIDR Working Paper WP-2023-022, 48 pages.
Rostock, Max-Planck-Institut für demografische Forschung (Mai 2023)
Open Access


Economic and social development are closely linked with fertility. Several studies have shown that the relationship follows an inverse J-shape: at low and intermediate levels of development, the association is negative; and at high levels of development the association is reversed and becomes positive. However, more recent research building on subnational and U.S. data found only mixed evidence for the inverse J-shape. In this paper, we draw on subnational data on development and fertility in the U.S. states between 1969 and 2018 to examine the relationship between development and fertility. Using a longitudinal approach and addressing several criticisms of the fertility reversal hypothesis, our results support the inverse J-shaped pattern, reconciling trends observed in the U.S. with those in other high-income countries. We also discuss potential explanations for why studies might not detect the inverse J-shape. Moreover, our findings provide insights into the mechanisms that link development and fertility, showing that gender equality and economic uncertainty mediate the relationship between development and fertility.

Schlagwörter: Vereinigte Staaten, economic and social development, fertility, fertility determinants
Das Max-Planck-Institut für demografische Forschung (MPIDR) in Rostock ist eines der international führenden Zentren für Bevölkerungswissenschaft. Es gehört zur Max-Planck-Gesellschaft, einer der weltweit renommiertesten Forschungsgemeinschaften.