The Effects of Similarity on Charitable Giving in Donor-Donor Dyads: A Systematic Literature Review

Giving circles and alumni campaigns are popular forms of nonprofit fund-raising practice that may lead to positive peer effects that promote charitable giving among similar individuals. However, do individuals always give more in the presence of similar others? Most research finds a positive social influence among similar individuals in donor-solicitor and donor-recipient dyads. However, in donor-donor dyads, the effects of social influence on charitable giving are mixed. Individuals' giving can be positively or negatively affected by other donors' giving. This systematic literature review (35 eligible studies) investigates how individuals' charitable giving is affected by the giving of others. Its major contribution is to extend the previous literature by proposing a new mechanism of decision making in charitable giving through an important psychological construct (similarity). It also identifies five critical factors that could help to explain inconsistent findings of similarity effects on two measures of charitable giving (giving propensity and giving amount). It also contributes to identifying a literature gap, suggesting future research directions, and providing important implications to fund-raising practice.