Anonymity and self-expression in online rating systems—An experimental analysis

Customer reviews are a fundamental part of online markets to establish trust between customers and sellers. Sharing experiences about products and services, however, might be accompanied with concerns for private information being shared and the threat of being involuntarily analyzed and clustered by third parties. Anonymous reputation systems ensure more privacy by preventing customers being analyzed and tracked by means of their reviews. However, this enhancement of privacy might also crowd out reviews, that are motivated by self-expression motives of the reviewers as these can be blunted by the introduction of anonymity. In this experimental study we therefore analyze whether anonymous reputation systems indeed have this drawback of blunting self-expression as a motive of customer reviews and whether altruistic attitudes moderate this effect. We find that the amount of ratings drops significantly when subjects are anonymous pointing to self-expression as a driver of customer reviews. Moreover, we find that altruistic subjects are not affected by the introduction of anonymity and, hence, provide significantly more reviews compared to non-altruists under anonymity. When we remove the veil of anonymity by implementing pseudonyms, this difference between altruists and non-altruists disappears and, overall, consumer welfare increases.