Do Pledges Lead to More Volunteering? An Experimental Study

The effect of pledges on donations is ambiguous. Pledges can boost donations because pledges make it easier for people to accept a request without incurring the costs of donating right away. However, pledges can also decrease donations because individuals who pledge renege on their promises. In this paper, we study the effect of pledges on volunteering using an online experiment. We find that pledges decrease immediate rejection to volunteering requests, but pledges are often reneged later, resulting in no overall change in volunteering rates. We provide a theoretical framework for understanding the conditions under which these results emerge.