How Thanking Peers Sustains Volunteer Participation in Public Goods: Parallel Field Experiments in Four Wikipedia Language Communities

This paper presents pre-registered parallel field experiments across four Wikipedia language communities (Arabic, German, Persian, Polish; N = 15,558 editors) to test the causal effect of private peer-to-peer gratitude on upstream reciprocity and sustained volunteer participation. Assignment to receive thanks increased contribution time by 11%, increased two-week contributor retention by 2.2 percentage points, and caused recipients to thank others 61% more — with 99.8% of those thanks directed upstream to third parties who had not previously exchanged thanks with the recipient.

Recommended citation: Matias, J. N., Kamin, J., Al-Kashif, R., He, W. P., Klein, M., & Pennington, E. "How Thanking Peers Sustains Volunteer Participation in Public Goods: Parallel Field Experiments in Four Wikipedia Language Communities." Proc Natl Acad Sci USA (PNAS). (Under review)