Mobile Messaging for Offline Group Formation in Prosocial Activities: A Large Field Experiment

Tianshu Sun, Guodong (Gordon) Gao, Ginger Zhe Jin

NBER Working Paper No. 21704
Issued in November 2015, Revised in February 2018
NBER Program(s):Industrial Organization

In this paper, we use mobile messaging to leverage recipients’ social ties and encourage offline prosocial activities in groups. In particular, we conduct a randomized field experiment with 80,000 blood donors and study how behavioral interventions and economic rewards motivate offline group formation. We find that two commonly used interventions—reminder messages and individual reward—are ineffective in motivating group formation because they do not compensate donors for the cost of bringing friends. In contrast, we find that group reward—a new reward that is contingent on a donor bringing a friend—is effective in motivating group formation. Furthermore, group reward tends to attract different types of donors, especially those who are traditionally less active in online social settings but have more local social ties. Structural estimation further reveals the underlying mechanisms, suggesting that group reward is four times more cost-effective than individual reward in driving total donation. Our study suggests that motivating offline group formation is a promising approach to boost prosocial activities.

download in pdf format
   (322 K)

email paper

Supplementary materials for this paper:

Machine-readable bibliographic record - MARC, RIS, BibTeX

Document Object Identifier (DOI): 10.3386/w21704

Mobile Messaging for Offline Group Formation in Prosocial Activities: A Large Field Experiment, forthcoming Management Science.

Users who downloaded this paper also downloaded* these:
Sun, Lu, and Jin w21312 Solving Shortage in a Priceless Market: Insights from Blood Donation
Monte, Redding, and Rossi-Hansberg w21706 Commuting, Migration and Local Employment Elasticities
Kuziemko and Washington w21703 Why did the Democrats Lose the South? Bringing New Data to an Old Debate
Glaeser, Ponzetto, and Zou w21794 Urban Networks: Connecting Markets, People, and Ideas
Abdulkadiroglu, Angrist, Narita, and Pathak w21705 Research Design Meets Market Design: Using Centralized Assignment for Impact Evaluation
NBER Videos

National Bureau of Economic Research, 1050 Massachusetts Ave., Cambridge, MA 02138; 617-868-3900; email:

Contact Us