Pledge campaigns to encourage charitable giving: a randomised controlled trial

This paper reports on a randomised controlled trial on the effects of pledging. The research was undertaken in Manchester, in partnership with the Community HEART charity. 11,812 households in two electoral wards were sent information about an upcoming charity campaign to develop school libraries in South Africa: they were told that in a few weeks they would be asked to donate a children???s book. Households were randomly assigned to receive differently worded requests. The trial tested: firstly whether asking people to pledge makes it more likely that they will later donate to a charitable campaign and secondly whether people are more likely to pledge and later donate if they are told their involvement will be made public. There is a limited amount of research on pledging and from the available research it is difficult to know whether pledging works or not: pledges are usually invited as part of a wider publicity campaign, making it difficult to identify the effect of the pledge on its own. In this paper we review the available literature on pledging, describe the research design and methods and present some very early results.