Managers in the fundraising sector face the constant challenge of solliciting donations from a population who may or may not have donated before. Rather than merely asking respondents what they wish to donate, it is standard practice to present a set of suggested amounts -the appeals scale- in making donation requests. With a large scale field trial, coupled with a donation database from a French charity, we find with a segment-level Bayesian model, a very significant influence of the appeals scale and of 'round' scale values, such as those appearing on common bank notes, on distribution of donations.
DESMET, P. (2003). Ask and Ye Shall Receive: The Effect of the Appeals Scale on Consumers' Donation Behavior. Journal of Economic Psychology, pp. 349-376.