Topic
Revenue Management and Pricing
Co-Topic 1
Revenue Management and Pricing
Co-Topic 2
Revenue Management and Pricing

Learning to Rank Under Strategic "Brush Wars"

12:51 PM - 1:09 PM
Qinzhen Li, NATIONAL UNIVERSITY OF SINGAPORE; Kevin Chen, CUHK; Yifan Feng, National University of Singapore.
We consider a dynamic learning and ranking problem of a digital platform. Uninformed of the products' intrinsic qualities, the platform strives to design a ranking rule that learns from historical traffic data while accounting for sellers' potential manipulation through "brushing" activities, such as fake orders or sales. We study a simple Experiment-Then-Commit (ETC) policy framework and characterize the sellers' strategic responses as a "brushing war" game. We find that in the limit with a long time horizon and many sellers, there is a "self-reinforcing" market equilibrium. That is, the sellers' brushing amounts increase in the product's qualities, thus helping with the platform's complete learning.