The project combined quasi-experimental econometric methods with large-scale survey and administrative data. Two primary studies were conducted. The first analyzed Belgium’s 2002 paternity leave reform using a Regression Discontinuity Design (RDD) and population-level administrative data. It confirmed the reform durably increased fathers’ daily childcare time. However, tracking children into early adulthood revealed no significant effects on their educational attainment (middle/high school completion, PISA scores), early labor market outcomes (employment, wages), or early family formation (cohabitation, parenthood). The second study expanded the scope to six European countries (Belgium, Denmark, France, Iceland, Norway, Sweden). Using an RDD and data from the “Project Implicit” platform, it measured subconscious gender attitudes via an Implicit Association Test (IAT). This research found that sons—but not daughters—exposed to fathers eligible for paternity leave developed significantly less gender-stereotypical attitudes. Follow-up analysis with EU-SILC survey data indicated these attitudinal shifts had behavioral consequences: affected sons in Scandinavia were more likely to enter high-skilled, female-dominated occupations (e.g. in healthcare or education).