Understanding and Overcoming Biases in Customer Reviews
This addresses biases in online reviews to help practitioners improve credibility and representation, but it is incremental as it builds on existing literature.
The paper analyzes data from four major online retailers and finds that email-prompted reviews are, on average, 0.5 stars higher and more stable over time than self-motivated web reviews, indicating social influence and selection biases in web reviews.
Our paper contributes to the literature recommending approaches to make online reviews more credible and representative. We analyze data from four diverse major online retailers and find that verified customers who are prompted (by an email) to write a review, submit, on average, up to 0.5 star higher ratings than self-motivated web reviewers. Moreover, these email-prompted reviews remain stable over time, whereas web reviews exhibit a downward trend. This finding provides support for the existence of social influence and selection biases during the submission of a web review, when social signals are being displayed. In contrast, no information about the current state of the reviews is displayed in the email promptings. Moreover, we find that when a retailer decides to start sending email promptings, the existing population of web reviewers is unaffected both in their volume as well as the characteristics of their submitted reviews. We explore how our combined findings can suggest ways to mitigate various biases that govern online review submissions and help practitioners provide more credible, representative and higher ratings to their customers.