Journal Of The Econometric Society

An International Society for the Advancement of Economic
Theory in its Relation to Statistics and Mathematics

Edited by: Guido W. Imbens • Print ISSN: 0012-9682 • Online ISSN: 1468-0262

Econometrica: Nov, 2022, Volume 90, Issue 6

Learning From Reviews: The Selection Effect and the Speed of Learning
p. 2857-2899

Daron Acemoglu, Ali Makhdoumi, Azarakhsh Malekian, Asuman Ozdaglar

This paper develops a model of Bayesian learning from online reviews and investigates the conditions for learning the quality of a product and the speed of learning under different rating systems. A rating system provides information about reviews left by previous customers. observe the ratings of a product and decide whether to purchase and review it. We study learning dynamics under two classes of rating systems: full history, where customers see the full history of reviews, and summary statistics, where the platform reports some summary statistics of past reviews. In both cases, learning dynamics are complicated by a selection effect—the types of users who purchase the good, and thus their overall satisfaction and reviews depend on the information available at the time of purchase. We provide conditions for complete learning and characterize and compare its speed under full history and summary statistics. We also show that providing more information does not always lead to faster learning, but strictly finer rating systems do.

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Supplemental Material

Supplement to "Learning From Reviews: The Selection Effect and the Speed of Learning"

Daron Acemoglu, Ali Makhdoumi, Azarakhsh Malekian, and Asu Ozdaglar

This appendix contains material not found within the manuscript.

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