Where oh where should we eat?
Perhaps the common social choice problem that any of us face in practice is when we find ourselves in a group that must choose one restaurant at which all of us will eat. We propose a method where, similar to the I-choose-you-cut rule for dividing a cake, individuals in the group take turns restricting the set of choices for the group. Specifically, under our method the first person restricts the set of restaurants to a certain number the second person restricts the set to a smaller number and so on until the last person in the group selects one restaurant. We derive a formula for choosing these numbers such that – under a natural assumption about individual preferences.the probability that the group will choose any individual’s favorite restaurant is equal for each individual.
That’s from an interesting recent working paper by Tim Groseclose and Jeff Milyo.
I do wonder why collective choices are not made in more efficient ways. Overall there is not enough deference to expertise and too much interest in finding a “lowest common denominator” of taste within the group. The real problem is to allow those who know to exert their influence, but without appearing like bullies. Yes I know the group cares more about harmony but that is precisely the problem: outlier tastes in the group end up frustrated. Maybe we should sever food decisions from all others, if this is possible. Then people could cede to the food expert, but without fear of future bullying in all other areas. As is sometimes the case in politics, the question is not “what is the proper social welfare function?” but rather “how do we get the right thing done?”