Self-selection and non-response biases in customers' hotel ratings - a comparison of online and offline ratings

User-generated hotel ratings have been found to be an important element in customers’ decision making. Nevertheless, most hotel ratings online show average ratings that are extremely positive. Thus, the question is raised of whether online ratings reflect objective evaluation of the reviewers. This study examines the distribution of online ratings and compares it the distribution of offline ratings. Online hotel score ratings reported on Booking.com were extracted and compared with offline rating scores from a field survey. Online and offline hotel ratings of eight hotels located in Seoul were collected. The ratings were compared using Welch’s t-test. Overall, both online and offline ratings for all eight hotels show generally positive distribution curves. The distribution curves exhibit shapes analogous to those considered to contain self-selection bias. The randomized offline ratings did not produce more moderate ratings as predicted. Thus, no indication of non-response bias was found. Practically, this study supports the notion that hotels listed on online travel agencies such as Booking.com may already have passed certain quality criteria, thereby providing competitive marketplaces for customers searching for hotels online.