Are Online Reviewers Susceptible to Unrelated, Random Events?

The increasing and widespread use of online reviews has sparked research that establishes the impact of reviews on sales and brand equity. In the consumer's perspective, online reviews, theoretically, supply reliable and useful information that would have been, otherwise, hard to acquire. Yet, there is an emerging empirical literature that finds systematic biases in reviews that originate either from social effects or consumer-producer matching effects. Here, we show that reviewing behavior in the field is even further susceptible to events that are exogenous, random and unrelated to consumption. Using a unique research setup with large rich field data, we are able to identify the effect of rain conditions on reviewing behavior during the provision of the review, days after consumption itself. First, we find that rain conditions increase the overall incidence of online reviews and that it is not an effect on timing. Second, we find that during rain conditions, reviewers systematically provide lower ratings. Third, we find that both the format and the text of reviews are significantly affected. Overall, our findings suggest that consumer preferences, or preferences to produce word-of-mouth, are malleable and susceptible to external events, days after consumption. We find suggestive evidence that the susceptibility of online ratings provision is associated with lack of experience and low confidence, and that it considerably weakens with higher reviewer experience, longer consumption duration and increasing reviewer age.