Reciprocity or Self-Interest? Leveraging Digital Social Connections for Healthy Behavior

Abstract

We examine the role of reciprocity enabled by digital social platforms for offline healthy behavior. Although reciprocity is a fundamental aspect of human psychology, its application in promoting healthy behavior has been limited. We conduct a large randomized field experiment with over 1,700 pairs of users on a mobile social network platform. Individuals in the reciprocity treatment group receive a gift from their friends and are asked to return this favor by participating in a running challenge. Their performance is compared to the self-interest incentives widely used in practice. Building on social exchange theory, we argue that reciprocity-based incentives will outperform self-interest incentives for motivating behavior change. We find that on average, reciprocity is stronger than self-interest in inducing exercise behavior by a substantial amount. Furthermore, our results reveal that the magnitude of the reciprocity effect is contingent on the social closeness between senders and receivers. Interestingly, social closeness has an inverted U-shaped influence on the reciprocity effect. The effect is strongest when closeness is moderate, and wanes when closeness is either too strong or too weak. Compared to the widely used self-interest based financial incentives, our findings offer a potentially more powerful avenue for mechanism design in promoting healthy behavior.

Keywords: Reciprocity, self-interest, healthy behavior, social connections, social closeness, social exchange theory

JEL Classification: I12