Education, family complexity and heterogeneous causal effects of parental separation

Objective: This study examines educational heterogeneity in the impact of parental separation on educational attainment, considering the full sequence of childhood family structural changes.Background: Studies have consistently associated parental separation with lower socioeconomic achievement. However, the underlying causes remain unclear, possibly due to self-selection or continued instability in the family environment.Method: This study employs structural causal modeling and Bayesian logistic regression to investigate the causal effect of childhood family structural changes on adult educational attainment using Finnish full-population register data (n = 272,962), focusing on cohorts born in 1987–1991 and their family members.Results: A substantial portion of the 17-percentage-point disadvantage of children from separated families was due to the selection of families into separation and further structural changes. Separation effects followed a U-shaped pattern, with the largest negative effects among families in the middle of the educational gradient. Stepparents did not exert positive or negative effects, except for highly educated parents’ children benefiting from stable stepfathers. Recurring family instability had the largest negative impact.Conclusion: The curvilinear relationship between parental and child education may partly explain the mixed results of previous studies.Implications: Given that recurring family instability was shown to be the most detrimental to children’s educational attainment, low-threshold guidance and support to aspiring and existing blended families might have the largest impacts on children of separated parents.