Empirical Bayes When Estimation Precision Predicts Parameters

Empirical Bayes shrinkage methods usually maintain a prior independence assumption: The unknown parameters of interest are independent from the known precision of the estimates. This assumption is theoretically questionable and empirically rejected, and imposing it inappropriately may harm the performance of empirical Bayes methods. We instead model the conditional distribution of the parameter given the standard errors as a location-scale family, leading to a family of methods that we call CLOSE. We establish that (i) CLOSE is rate-optimal for squared error Bayes regret, (ii) squared error regret control is sufficient for an important class of economic decision problems, and (iii) CLOSE is worst-case robust. We use our method to select high-mobility Census tracts targeting a variety of economic mobility measures in the Opportunity Atlas (Chetty et al., 2020; Bergman et al., 2023). Census tracts selected by close are more mobile on average than those selected by the standard shrinkage method. For 6 out of 15 mobility measures considered, the gain of close over the standard shrinkage method is larger than the gain of the standard method over selecting Census tracts uniformly at random.