Abstract
In this research, we investigate the prevalence, robustness and possible reasons underlying the polarity of online review distributions with the majority of the reviews at the positive end of the rating scale, a few reviews in the mid-range and some reviews at the negative end of the scale. Putting together a large dataset of online reviews -- over 280 million reviews from 25 major online platforms -- we find that most reviews on most platforms exhibit a high degree of polarity, but the platforms vary with respect to the degree of polarity based on how selective customers are in reviewing products on the platform. Using cross-platform and multi-method analyses, including secondary data, experiments as well as survey data, we empirically confirm polarity self-selection, described as the higher tendency of consumers with extreme evaluations to provide a review as an important driver of the polarity of review distributions. Additionally, we describe and demonstrate that polarity self-selection and the polarity of the review distribution reduce the informativeness of online reviews.