Research Discussion Paper – RDP 2019-08 The Well-meaning Economist

Abstract

Economists usually inform policymakers with conclusions that come from studying the conditional expectation, i.e. arithmetic mean, of some potential outcome. But there are other means to study, from the same ‘quasilinear’ family. And they can support very different conclusions. In trade research, for instance, studying other means can transform the perceived roles of colonial history, geography, and trade wars. In wages research, studying other means can reverse perceived earnings differentials between groups. Similar scenarios will be common in other tasks of policy evaluation and forecasting. To choose means well I propose selection criteria, which also consider options that are outside of the quasilinear family, such as quantiles. Optimal choices are application-specific and ideally accommodate the preferences of the relevant policymaker. In the wages case, policymaker aversion to inequality makes it sensible to reject the arithmetic mean for another quasilinear one.