Is the Simple Law of Mobility Really a Law? Testing Clark's Hypothesis

Recent work by Gregory Clark and co-authors uses a new surnames approach to examine intergenerational mobility, finding much higher persistence rates than traditionally estimated. Clark proposes a model of social mobility to explain the diverging estimates, including the crucial but untested hypothesis that traditional estimates of intergenerational persistence are biased downward because they use only one measure (e.g. earnings) of underlying status. I test for evidence of this using an approach from Lubotsky and Wittenberg (2006), incorporating information from multiple measures into an estimate of intergenerational persistence with the least attenuation bias. Contrary to Clark's prediction, I do not find evidence of substantial bias in prior estimates.