Relatrice: prof.ssa Beatrice Braut - Dipartimento di Economia, Università di Genova 

Step-tracking apps aim at promoting a healthier lifestyle, but users' lack of compliance is an issue. In this study, we implement a large RCT to examine the effectiveness of different framing and duration of text message reminders on engagement with the app and walking habits. We conduct a 7-weeks experiment with 20,187 users of the app WeWard in France. We send three types of messages, each of them leveraging a different behavioral feature, compared to a generic reminder, and we vary the duration of the intervention from 1 to 3 weeks. We document that the message providing information about peers' performance increases app utilization. However, no type of message affects the number of steps tracked by the app.