Work

Causal effect of school-entry age on long-run family formation: Quasi-experimental evidence from 14 million individuals in Vietnam

Year: 2026

Type: article

Abstract: School-entry age has been suggested to affect human capital development. Little is known, however, about the impacts of school-entry age on long-run outcomes, particularly in lower-income countries where most children and adolescents worldwide reside. We exploit a natural experiment based on school-entry rules in Vietnam to examine the causal effect of school-entry age on educational outcomes and family formation. Data on children's school-entry age, education, childbearing, marriage, and mortality in the next generation are extracted from the longitudinal Young Lives study conducted between 2001 and 2016 (n = 10,746) and the Population and Housing Censuses of 1989, 1999, and 2009 (n = 14,251,279). In adolescence, children who enter school at an older age stay in school longer and delay childbearing and marriage. In adulthood, women who enter school at an older age are 3.1 percentage points less likely to have given birth (P < 0.001, 95% CI: 3.0–3.3), have 0.1 fewer children (P < 0.001, 95% CI: 0.09–0.10), are 2.4 percentage points less likely to marry (P < 0.001, 95% CI: 2.3–2.5), and are 8% less likely (0.4 percentage points, P < 0.001, 95% CI: 0.3–0.5) to experience the death of a child. Decomposition analyses suggest that incapacitation mechanisms may play a larger role in shaping family formation outcomes than human capital pathways. These findings demonstrate how subtle shifts in early institutional timing can have profound and enduring impacts, with implications for education, health, and social policy globally.

Source: PNAS Nexus

DOI: 10.1093/pnasnexus/pgag119

Authors: Ishaan Busireddy, Janny Liao, Dat Hoang Vu, Tam Ngo Minh Tran, Jan-Walter De Neve