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' socio-economic status. This topic is central in social science, and there is no doubt that research has intensified during...

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...