Positive effects of his and her income on first births: couple-level evidence from longitudinal tax data in Italy

This study adopts a couple-level approach to assess whether higher-income women (men) experience lower (higher) fertility due to opportunity costs and conventional gender norms or whether income pooling within couples facilitates parenthood. We test the well-established gendered relationship between income and fertility in Italy, a country historically known for its division of family roles along traditional gender lines. Utilizing longitudinal tax data (2003–2022; n = 8,039,372 person-years) from Tuscany—a region representing Italian-average levels of economic development and gender equality—we apply discrete-time event-history analyses. Results show that higher income for both men and women increases the likelihood of the first birth. Married couples in which both partners are high earners (low earners) are the most (least) likely to become parents, while hypergamous/hypogamous couples lie in between. These findings challenge traditional sex-specialization models and support the view that couples’ income pooling is a key factor for parenthood, which might compensate for weak public policies through private outsourcing. The positive income–fertility association grew slightly stronger in the late 2010s, suggesting rising economic prerequisites to union formation and parenthood. Overall, the findings highlight the economic stratification of parenthood in a context of high childlessness and rising costs of having a child.