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How good is a group decision?

Author

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  • Ye Lu

    (City University of Hong Kong)

  • Miao Song

    (The Hong Kong Polytechnic University)

  • Xiaoling Zhong

    (Shenzhen MSU-BIT University)

Abstract

This paper studies a committee’s competency in making a correct judgement. Specifically, we examine how the committee’s competency compares with the average, median, lowest, and highest competencies of individual members. We propose novel measures for these comparisons and demonstrate that the lower and upper bounds of each committee member’s competency have distinct and significant effects on the committee’s overall competency. Furthermore, our research reveals an interesting relationship between the committee’s competency and the distribution of member competencies. We find that as the number of members with competencies higher than $$\frac{1}{2}$$ 1 2 increases, the likelihood of the committee’s competency surpassing that of individual members also increases. Conversely, when more members possess competencies lower than $$\frac{1}{2}$$ 1 2 , the likelihood of the committee’s competency being lower than that of individual members also rises. To support this observation, we present theoretical findings from a comparison of the committee’s competency with the minimum and maximum competencies of its members.

Suggested Citation

  • Ye Lu & Miao Song & Xiaoling Zhong, 2025. "How good is a group decision?," Public Choice, Springer, vol. 203(3), pages 445-464, June.
    • Handle: RePEc:kap:pubcho:v:203:y:2025:i:3:d:10.1007_s11127-024-01210-z
    DOI: 10.1007/s11127-024-01210-z
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    References listed on IDEAS

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    1. Ruth Ben-Yashar & Shmuel Nitzan, 2017. "Are two better than one? A note," Public Choice, Springer, vol. 171(3), pages 323-329, June.
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