Abstract:
This article reviews the growing literature on age at school entry (ASE) and its effects across the life course. ASE affects a wide range of outcomes, including education, labor-market performance, health, social relationships, and family formation. We synthesize the evidence using a conceptual framework that distinguishes four empirically intertwined ASE components: starting age, age at outcome, relative age, and time in school. While ASE effects are often substantial and persistent, many studies estimate bundled impacts without isolating specific components. A central lesson from the literature is that most estimated effects reflect bundled timing and institutional mechanisms rather than isolated maturity advantages, with interpretation depending on outcome construction and empirical design. We conclude by highlighting key gaps, particularly around relative age and long-run outcomes, and directions for future research.