|By:||Attila Ambrus (Department of Economics, Duke University)
Ben Greiner (School of Economics, Australian School of Business, the University of New South Wales)
Parag A. Pathak (Department of Economics, MIT)
This paper experimentally investigates how individual preferences, through unrestricted deliberation, are aggregated into a group decision in two contexts: reciprocating gifts and choosing between lotteries. In both contexts, we find that median group members have a significant impact on the group decision, but the median is not the only influential group member. Non-median members closer to the median tend to have more influence than other members. By investigating the same individual’s influence in different groups, we find evidence for relative position in the group having a direct effect on influence. These results are consistent with predictions from a spatial model of dynamic bargaining determining group choices. We also find that group deliberation involves bargaining and compromise as well as persuasion: preferences tend to shift towards the choice of the individual’s previous group, especially for those with extreme individual preferences.
|Keywords:||group decision-making, role of deliberation, social influence|
|JEL:||C72 C92 H41|
==Notes by yinung==
從賽局理論的角度看, 集體決策較個人決策來得理性 (rational), 因其可避免認知錯誤與限制。
不過集體決策也因此不見得會提高社會福利 (集體決策比較 self-interest)
the optimal size of the group ( A useful starting point here is Forsyth’s (2006) work)
In this paper, we describe what economists have learned about differences between group and individual decision-making. This literature is still young, and in this paper, we will mostly draw on experimental work (mainly in the laboratory) that has compared individual decision-making to group decision-making, and to individual decision-making in situations with salient group membership. The bottom line emerging from economic research on group decision-making is that groups are more likely to make choices that follow standard game-theoretic predictions, while individuals are more likely to be influenced by biases, cognitive limitations, and social considerations. In this sense, groups are generally less “behavioral" than individuals. An immediate implication of this result is that individual decisions in isolation cannot necessarily be assumed to be good predictors of the decisions made by groups. More broadly, the evidence casts doubts on traditional approaches that model economic behavior as if individuals were making decisions in isolation.
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