["Journal of Risk and Insurance, EarlyView. ", "\nAbstract\nThis paper examines how sex ratios affect household commercial pension demand in a patrilocal society. Exploiting the cross‐county variations in sex ratios, we estimate the sex‐ratio effects on parental pension decision‐making in the first‐son families relative to the first‐daughter ones. We find that a one‐standard‐deviation increase in the local sex ratio would decrease commercial pension take‐up by 1.08 percentage points, or 51.6 percent, for parents with a firstborn son compared with those with a firstborn daughter. We also observe similar patterns in the premium contribution of commercial pensions. Mechanism analyses suggest that the pension disparity by the first child's gender is attributed to external financial support and intensive competition caused by oversupplied men in the marriage market.\n"]