"Popularity Effect" in User-Generated Content: Evidence from Online Product Reviews

Online product reviews are increasingly important for consumer decisions, yet we still know little about how reviews are generated in the first place. In an effort to gather more reviews, many websites encourage user interactions such as allowing one user to subscribe to another. Do these interactions actually facilitate the generation of product reviews, and more important, what kind of reviews do such interactions induce? We study these questions using data from epinions.com, one of the largest product review websites where users can subscribe to one another. By applying both panel data and flexible matching methods, we find that as users become more popular, they produce more reviews and more objective reviews; however, their numeric ratings systematically change, and become more negative and more varied. Such tradeoff has not been previously documented, and has important implications for not just product review websites, but user-generated content sites as well.