Paternity Leave and the Motherhood Penalty: How Within‐Couple Inequality Conditions Policy Impact

ABSTRACT Motherhood‐related labour market penalties remain a major driver of the gender employment gap. Father‐specific paternity leave is often promoted as a policy tool to support maternal employment, yet evidence of its effectiveness is mixed. This article examines whether—and under what conditions—paternity leave reduces key dimensions of the motherhood penalty, including the timing of return to work, the terms of labour market re‐entry, and perceived professional sacrifice. We use original survey data from 1800 mothers whose children were born before and after Spain's 2021 paternity leave reform, which granted fathers 16 weeks of non‐transferable leave, the same duration as maternity leave. Regression models show that equal, non‐transferable paternity leave does not significantly shorten employment interruptions. The main exception is mothers earning roughly the same as their partners: they are significantly more likely to return earlier to full‐time work after the reform and to report fathers' involvement as a facilitator, attesting to the moderating role of intra‐household equality on policy effects. However, mothers' perceptions of professional sacrifice remain largely unchanged after the reform. At least in the short term, father‐specific entitlements alone appear insufficient to reduce the motherhood penalty, as its impact is constrained by pre‐existing gender inequalities.