Caspi et al. (2002, 2003), Guo et al. (2008a), and Pescosolido et al. (2008) all claim to have demonstrated allele-by-environment interactions, but in all cases environmental influences are potentially endogenous to the unmeasured genetic characteristics of the subjects and their families. Thus,...

An extensive literature has documented a robust correlation between socioeconomic status--measured in a variety of ways--and health outcomes; however, much uncertainty remains regarding what causal processes underlie this association. The present paper builds on a growing literature that seeks...