The Rise and Fall of Stars: The Swaying Effects of Displaying Online Rating Trends*

Despite the prevalence of single average ratings on online rating platforms, they mask nuanced insights in online ratings. This paper contributes to the burgeoning literature on this topic by illustrating the importance of critical, yet overlooked, information obscured by single average ratings: trend information in online ratings. Online ratings are not static; they change over time as product/service quality changes and consumer expectations and preferences shift. The trend information embedded in online ratings enables consumers to go beyond past ratings to extrapolate expected ratings in the future. I focus on this aspect of online ratings and investigate (a) the effects of displaying trends in online ratings on consumer purchase decisions, (b) the mechanism mediating these trend effects, and (c) the situational contingency factors moderating these trend effects. Drawing on psychological momentum (PM) theory and four randomized controlled experiments (total n=2,015), this paper shows that the presence and explicit presentation of trends in online ratings create a PM experience that sways consumer decisions. It further demonstrates that the potency of these trend effects depends on the trend’s norm alignment, valence, surface forms of online ratings, and trend continuity. I will discuss the contributions of these findings to the research and practice of online ratings.