On the Production of Skills and the Birth-Order Effect

First-born children tend to outperform their younger siblings on measures such as cognitive exams, wages, educational attainment, and employment. Using a framework similar to Cunha and Heckman (2008) and Cunha, Heckman, and Schennach (2010), this paper finds that differences in parents’ investments across siblings can account for more than one-half of the gap in cognitive skills among siblings. The study’s framework accommodates for endogeneity in parents’ investments, measurement error, missing observations, and dynamic impacts of parental investments.