Sex of the First Child and Mental Health of the Parents Later in Life. A Natural Experiment.

Giambattista Salinari , University of Sassari
Virginia Zarulli, University of Padua
Gianni Carboni, University of Sassari

This study investigates whether the sex of the firstborn child has a causal effect on parental cognitive decline in later life. Leveraging a standard natural experiment design, we treat the sex of the firstborn as a natural randomizer, which allows for comparisons across groups while controlling for both observed and unobserved confounders. Using data from the Survey on Health and Retirement in Europe (SHARE) concerning over 60,000 individuals, we find that having a firstborn son is associated with significantly worse outcomes in immediate and delayed word recall, verbal fluency (among fathers), depression, and perceived quality of life. The effect sizes are small but statistically robust. In addition to identifying the overall effect, we explore potential causal mechanisms using a causal triangulation strategy. We find no evidence supporting biological or marital-status-based pathways. Instead, our findings suggest that the observed effect is primarily mediated by two factors: the higher mortality risk of sons and the more frequent contact between daughters and their aging parents. These results indicate that cognitive functioning in old age may be shaped by the accumulation of social and emotional shocks across the life course. Our study contributes to the literature on family structure and aging, and highlights the value of natural experiments in causal inference.

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 Presented in Session 22. Gender, Sex and Health