Comparative feedbacks under incomplete information

Comparative feedbacks, that is personalized messages describing how one's behavior compares to that of relevant others, are currently widely used in order to change people's behaviors. Such feedbacks may induce recipients to update their beliefs about both reachable material outcomes and perceived self/social esteem. Both channels are very hard to disentangle in the field, which notably makes welfare analysis a very challenging task. This paper uses an online experiment that makes it possible to focus, within the considered setting, on the role of pure information on material outcomes. Despite an absence of normative pressure, comparative feedbacks are found to trigger comparable or even greater changes in behaviors than other kinds of informative and more accurate feedbacks. A possible explanation may be that comparative feedbacks more effectively conveyed to participants the idea that it should not be too difficult for them to reach a better outcome.