Group Size and Collective Decision Making

group size and collective decision-making When there is one, of course "one person decides" (dictatorship). The time of two is special, and majority rule and unanimous are equal.

• I don't think there is much difference between two people talking and making a unanimous decision and one person making a decision after listening to the other person carefully. I feel like when you get up to 10 or so people, one person should make the decision.
• Why is that?
• One person listens to N people to make a decision, O(N), and N people talk to each other, O(N^2), because the cost of the latter increases faster. The problem starts to appear after 30 people.
• Because it would be too much for one person to ask, even if it is O(N).
  • When a majority of people feel that their opinions are not being heard or ignored, they begin to oppose the dictatorship.
• So we needed a mechanism to make decisions in a way that wasn't just one person.
  • One example of its implementation is majority voting.
  • Indirect democracy is one of them.
    • Assumption that elected officials will deliberate?
    • If so, then the limit is about 30 senators.

If "one person becomes unreasonable to listen" is a factor preventing one person from making decisions, then AI's enhancement of human cognitive abilities would increase the number of areas in which a dictatorship would be preferable.

Well, either way, at the level of tens of thousands of people, you need a non-human mechanism.

This page is auto-translated from /nishio/グループのサイズと集団的意思決定 using DeepL. If you looks something interesting but the auto-translated English is not good enough to understand it, feel free to let me know at @nishio_en. I'm very happy to spread my thought to non-Japanese readers.