American Economic Review
Firms' incentives to manufacture biased user reviews impede review usefulness. We examine the differences in reviews for a given hotel between two sites: Expedia.com (only a customer can post a review) and TripAdvisor.com (anyone can post). We argue that the net gains from promotional reviewing are highest for independent hotels with single-unit owners and lowest for branded chain hotels with multi-unit owners. We demonstrate that the hotel neighbors of hotels with a high incentive to fake have more negative reviews on TripAdvisor relative to Expedia; hotels with a high incentive to fake have more positive reviews on TripAdvisor relative to Expedia.
Mayzlin, Dina; Dover, Yaniv; and Chevalier, Judith, "Promotional Reviews: An Empirical Investigation of Online Review Manipulation" (2014). Open Dartmouth: Faculty Open Access Articles. 2386.