From Blackwell Dominance in Large Samples to Rényi Divergences and Back Again

S-Tier
Journal: Econometrica
Year: 2021
Volume: 89
Issue: 1
Pages: 475-506

Authors (4)

Xiaosheng Mu (not in RePEc) Luciano Pomatto (not in RePEc) Philipp Strack (Yale University) Omer Tamuz (not in RePEc)

Score contribution per author:

2.011 = (α=2.01 / 4 authors) × 4.0x S-tier

α: calibrated so average coauthorship-adjusted count equals average raw count

Abstract

We study repeated independent Blackwell experiments; standard examples include drawing multiple samples from a population, or performing a measurement in different locations. In the baseline setting of a binary state of nature, we compare experiments in terms of their informativeness in large samples. Addressing a question due to Blackwell (1951), we show that generically an experiment is more informative than another in large samples if and only if it has higher Rényi divergences. We apply our analysis to the problem of measuring the degree of dissimilarity between distributions by means of divergences. A useful property of Rényi divergences is their additivity with respect to product distributions. Our characterization of Blackwell dominance in large samples implies that every additive divergence that satisfies the data processing inequality is an integral of Rényi divergences.

Technical Details

RePEc Handle
repec:wly:emetrp:v:89:y:2021:i:1:p:475-506
Journal Field
General
Author Count
4
Added to Database
2026-01-29