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The Impact of a Pledge Request and the Promise of Publicity: A Randomized Controlled Trial of Charitable Donations


  • Data and coding information are available from the UK Data Archive, <> or the corresponding author for replication purposes. The research study is part of the Rediscovering the Civic and Achieving Better Outcomes in Public Policy Project (see, funded by the Economic and Social Research Council, Department of Communities and Local Government and the North West Improvement and Efficiency Partnership, grant reference: RES-177-025-0002. The authors are grateful to Don Green, David Torgerson, and two anonymous reviewers for comments on earlier versions.

Direct correspondence to Sarah Cotterill, Centre for Biostatistics, Institute of Population Health, University of Manchester, Salford Royal NHS Foundation Trust, Stott Lane, Salford, M6 8HD, UK <>.



This study investigates whether asking people to make a pledge causes them to donate to a charitable cause and whether the promise of public recognition increases the effectiveness of the request.


A randomized controlled trial in Manchester, United Kingdom, where households were sent letters asking them to donate a book for school libraries in South Africa.


People who are asked to make a pledge and offered local public recognition are more likely to make a book donation than the control group. The combination of requesting a pledge and offering publicity raises book donations from 7.3 percent to 8.9 percent of households, an effect size of 22 percent. Asking people to pledge alone, without the promise of publicity has no statistically significant impact on giving.


Combining a pledge request and the promise of local publicity increases individual charitable donations.