Estimating the effect of mother’s schooling on children’s schooling using a sample of adoptees

In a recent paper Behrman and Rosenzweig (2002) present empirical evidence that contradicts the conventional wisdom that maternal schooling has a bigger effect on the child’s schooling than that of her husband. They consider the impact of parental schooling on child schooling in the presence of unmeasured ability and assortative mating. Using twin data, they come to the surprising conclusion that the mother’s schooling has little if any impact on the schooling of her child, holding everything else (including unobserved ability factors of either mother or father) constant. Their findings –I reason– must be bolstered with further support. This paper considers the effects of unobserved inherited abilities on the child’s schooling, but, instead of twinning, obtains identification from adopted children. If adopted children share only their parents’ environment and not their parents’ genes, any relation between the schooling of adoptees and their adoptive parents is driven by the influence parents have on their children’s environment, and not by parents passing on their genes. Controlling for inherited abilities and assortative mating I find that the association between mother’s (but not ∗This research is part of the NWO priority program on schooling, labour market performance and economic development. I thank Anders Björklund, Mikael Lindahl, Hessel Oosterbeek, Wim Vijverberg and an anonymous referee for their helpful comments. Support for collection and dissemination of data from the Wisconsin Longitudinal Study has been provided by the National Institute on Aging (AG-9775), the National Science Foundation (SBR-9320660), the Spencer Foundation, and the Center for Demography and Ecology and the Vilas Estate Trust at the University of Wisconsin-Madison. Only I bear the responsibility for the further analysis or interpretation of these data. Data and documentation from the Wisconsin Longitudinal Study are available at http://dpls.dacc.wisc.edu/WLS/wlsarch.htm. Correspondence to: Erik Plug, NWO program Scholar, Department of Economics and Econometrics, University of Amsterdam, Roetersstraat 11, 1018 WB Amsterdam, The Netherlands, e: [email protected], t: +31.(0)20.5256964, f: +31.(0)20.5254310. 1“The human capital of the mother is usually more closely related to the attainment of the child than is that of the father.” (Haveman and Wolfe, 1995 p.1855)