“I'll give it to you if it's such a ‘small' amount”: Prosocial behavior based on delay discounting and micro-donation

抄録

Charitable donations play an important role in the upliftment of a society. This study examines how to facilitate donations by subjective value of the money. Previous studies have shown that people generally discount delayed value of a reward with delay of receipt. We conducted an online experiment in which an extra reward was handed out by lottery to participants and they were asked to make a judgment on the extra reward, and used a 3 (amount of extra reward: 50/500/1000 yen) × 2 (delay: a day/a month) design resulting in six conditions. We hypothesized that the smaller the amount of an extra reward and the more it is delayed, the lower the subjective value of the reward becomes, and the more people would be willing to donate. Two-hundred and two undergraduates were randomly assigned to one of the six conditions. They were asked to answer a questionnaire measuring participants' delay-discounting rates, social value orientation (SVO), subjective socioeconomic status (subjective SES), and money beliefs. They were then told they had received an extra reward and were required to choose one of three options for the delayed extra reward: receive, reject, or donate. The results showed that a smaller extra reward and higher delay-discounting rates increased donation choice, but we could not obtain the effect of the delay in time until the participants received the extra reward. Therefore, we concluded that reducing the subjective value of the money could promote donation.