["Population and Development Review, Volume 48, Issue 2, Page 303-330, June 2022. ", "\nAbstract\nFamily formation patterns in the postindustrial world have changed markedly in the past several decades. Fertility rates have declined, cohabitation rates have increased, age at marriage has gone up, and nonmarital childbearing has become more common in most postindustrial settings. A dominant theoretical explanation for these changes is second demographic transition (SDT) theory, which posits widespread value change towards individualism and postmaterialist concerns. In contrast, gender equity theory emphasizes structural changes, including women's increased participation in the public sphere and the resulting incompatibility of women's domestic and public roles given the slower adaptation on the part of families and institutions to adapt to women's new roles. We test the predictions of these two theoretical frameworks by analyzing fertility decline in 27 European societies. We find evolving gender egalitarianism, measured by the prevalence of gender‐egalitarian attitudes, to have greater explanatory power than SDT‐related ideational changes. The gender equity framework is particularly relevant in explaining the recent fertility trajectories of Central, Eastern, and Southern European countries.\n"]