Is the Whole Equal to the Sum of its Parts? Exploring the Impact of Inconsistency on Perceived Helpfulness of a Set of Reviews

Despite a growing literature on the helpfulness of individual reviews, scant attention has been paid to the helpfulness of a set of reviews. Moreover, it is generally assumed that the helpfulness of a review set can be derived from averaging the individual reviews’ helpfulness evaluations. Drawing on bounded rationality theories, we hypothesize that this assumption may not always be valid, and that consumers’ helpfulness perception of a review set is also determined by inter-review consistency. A carefully designed experiment revealed that the whole differs from the sum of its parts when the reviews are consistent with each other or are contradicting each other, but does not differ when the reviews contain mixed, non-contradicting opinions. These findings deepen our understanding of inconsistency in online reviews and have a potential to change how reviews should be presented to the consumers.