English

Distributions of Posterior Quantiles via Matching

Theoretical Economics 2024-02-28 v1

Abstract

We offer a simple analysis of the problem of choosing a statistical experiment to optimize the induced distribution of posterior medians, or more generally qq-quantiles for any q(0,1)q \in (0,1). We show that all implementable distributions of the posterior qq-quantile are implemented by a single experiment, the qq-quantile matching experiment, which pools pairs of states across the qq-quantile of the prior in a positively assortative manner, with weight qq on the lower state in each pair. A dense subset of implementable distributions of posterior qq-quantiles can be uniquely implemented by perturbing the qq-quantile matching experiment. A linear functional is optimized over distributions of posterior qq-quantiles by taking the optimal selection from each set of qq-quantiles induced by the qq-quantile matching experiment. The qq-quantile matching experiment is the only experiment that simultaneously implements all implementable distributions of the posterior qq-quantile.

Keywords

Cite

@article{arxiv.2402.17142,
  title  = {Distributions of Posterior Quantiles via Matching},
  author = {Anton Kolotilin and Alexander Wolitzky},
  journal= {arXiv preprint arXiv:2402.17142},
  year   = {2024}
}