In every society for which we have data, people’s educational achievement is positively correlated with their parents’ education or with other indicators of their parents’ socioeconomic status. This topic is central in social science, and there is no doubt that research has intensified...

Massive cross-sectional evidence exists indicating that children of more educated parents outperform their schoolmates. However, evidence for causal interpretation of this association is weak. We examine a causal relationship using two approaches for identification within the same data: cousins...