Mobile Messaging for Offline Social Interactions: A Large Field Expeiment

While much research has examined the role of technology in moderating online user connections, how IT motivates offline interactions among users is much less understood. Using a randomized field experiment involving 80,000 participants, we study how mobile messaging can leverage recipients' social ties to encourage blood donation. There are three main findings: first, both behavior intervention (in the form of reminder message) and economic reward (in the form of individual or group reward) increase donations, but only the messages with group reward are effective in motivating more donors to donate with their friend(s); second, group reward tends to attract different types of donors, especially those who are traditionally less active in online social setting; and third, across all treatments, message recipients donate a greater amount of blood if their friends are present. Structural estimation further suggests that rewarding group donors is four times more cost-effective than rewarding individual donors. Based on the structural estimates, we perform policy simulations on the optimal design of mobile messaging. The method of combining structural model and randomized field experiment opens new frontiers for research on leveraging IT to mobilize a user's social network for social good.