Promotional Reviews: An Empirical Investigation of Online Review Manipulation
研究比较了Expedia（仅顾客可评）和TripAdvisor（人人可评）上同一酒店的评论差异，发现独立单体酒店更可能发布促销性正面评论，其周边酒店在TripAdvisor上的负面评论也更多。
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 multiunit 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.