「寡きを患えず、均しからずを患う」? : グループの意思決定におけるパレート原理の作用 Do people pursue distributive justice over social efficiency? : The functioning of Pareto optimality in group decision making
This paper addresses psychological dilemmas between pursuing distributive justice and sacrificing social efficiency in reward allocation. Previous research by Ohtsubo, Kameda, & Kimura (1996) showed that individuals often commit themselves to a specific distributive principle (such as equality or equity), endorsing a reward allocation scheme that is subjectively fairer but objectively inferior in terms of Pareto optimality. We have revisited this phenomenon in a reward allocation context by groups. Participants were first provided a scenario in which a group of people won a prize by collaboration, and were then asked to evaluate various reward allocation schemes as a neutral third party. Participants in the group condition discussed these schemes and made a collective recommendation in three-person groups. Participants in the individual condition made the identical decision alone. The results revealed that groups recommended a less fair, but Pareto-superior allocation scheme more often than individuals working alone. A follow-up experiment indicated that accountability of decisions to the beneficiaries underlies the enhanced role of Pareto axiom in group decision making.
社会心理学研究 20(1), 26-34, 2004