Why educated mothers don't make educated children. A statistical study in the intergenerational transmission of schooling

More educated parents are observed to have better educated children. Researchers trying to control for unobserved ability have found conflicting results: in most cases, they have found a strong positive paternal effect but a negligible maternal effect. In this paper, I use a population of twins from Norwegian Register data and evaluate the impact on the robustness of the estimates of the characteristics of the samples commonly used in this strand of research: samples of small size, with low variability in parental education, not randomly selected from the population. The part of the educational distribution involved in any identification strategy seems to be the key aspect to take into account to reconcile previous results from the literature.