The question that animates this paper is whether a standardized protocol for measuring the amount and contours of intergenerational mobility in the United States might usefully be established. Thoughout our discussion, we understand "intergenerational mobility" to refer to the association between (a) the social standing of an individual’s family of origin (as assessed when the individual is growing up), and (b) the social standing of that same individual when she or he is an adult.