On the Evaluation of Economic Mobility

This paper presents a framework for the evaluation and measurement of "reversal" and "origin independence" as separate aspects of economic mobility. We show that evaluation depends on aversion to multi-period inequality, aversion to inter-temporal fluctuations, and aversion to future risk. We construct "extended Atkinson indices" that allow us to quantify the relative impact of reversal and origin independence on welfare. We apply our approach to the comparison of income mobility in Germany and in the U.S.. When aversion to inequality is the only consideration, the U.S. gains more from mobility than Germany. This reflects similar gains from reversal in the two countries but greater gains in the U.S. from origin independence. The introduction of aversion to intertemporal fluctuations and aversion to future risk makes the impact of mobility in the two countries more similar.