Notes: This table reports OLS and IV estimates for the educational outcome equation (with high school admission as dependent variable) and decomposed effects of sibling gender on the outcome, with fertility choice being measured by Sibsize. The corresponding results for fertility choice being measured by Morethan2 are reported in Table 8. The first-stage F-statistics are reported in Table 7. The samples include 416,315 firstborn females and 434,729 firstborn males, who were born between 1978 and 1984 and have at least one sibling. We exclude the interaction between the twins instrument and sibling gender from the first stage for Columns 2 and 7, while we include it for Columns 3 and 8 in order to be comparable to Columns 5 and 10. The decomposed effects are measured according to Equations 4–6 as summarized: AIE = β₂{E[M|D = 1] – E[M|D = 0]}, ADE = β₁ + β₃E[M|D = 1], CDE = β₁ + β₃E[M]. AIE and ADE are evaluated at the conditional mean of M = Sibsize: (E[M|D = 1], E[M|D = 0]) = (2.5947, 3.0255) for first born females and (2.4975, 2.5993) for first born males, while CDE is evaluated at the unconditional mean E[M] = 2.8032 for firstborn females and 2.5471 for firstborn males. We control for the full set of dummies for urban, the subject’s age and district of birth, parents’ education and years of birth, and mother’s age at the first birth. Robust standard errors are reported in parentheses.