I would be very careful about practical consequences of Arrow theorem, because the theorem is mostly an artifact of static decision making. You shall read at least this paper:
>there is at least one decision rule (the majority rule) that guarantees that a well-defined social choice exists.
Is well-definedness the important criterion? I suppose there's not much point if the result lacks that property, but it seems far from sufficient.
>If establishing a consensus is one of the considerations that should determine which collective choice mechanism to adopt, it is not necessarily the only one. The collective decision process is also valuable in itself
Is this supposed to be obvious? I am puzzled by it. Since consensus is so difficult to achieve, I can understand if someone wants to abandon it and adopt some other guideline. I suppose I could argue for the proposition by imagining a thought experiment, where we had two candidate methods that both satisfied consensus. Then we might wish to compare them on other criteria. But that depends on eliminating the relevance of consensus first, which seems practically infeasible if not quite logically impossible.
> the choice of a collective choice mechanisms is also a social choice problem and all the points that Arrow has mentioned before also applies. To avoid an infinite regress, Arrow concludes that unanimity is needed at some point. We are thus back to square one, which is clearly not satisfactory.
This points to the relevance of consensus. It has the unusual property that there are no disputes that need to be resolved. If there was a dispute, that would indicate a lack of consensus. Perhaps we can reach consensus on the desirability of consensus? No, never mind.
>the possibility of making social choices that are justified and legitimate.
Isn’t consensus again the proper basis for justification and legitimacy? As long as there is dispute, this is in question. Since we cannot adopt the gods' perspective and just calculate the right answer, the second best is an answer no one thinks is worth changing. That might be either a good answer that is easy to change or a mediocre answer that is costly to change.
Perhaps subsidiarity is part of the answer. When there is dispute, disputants can apply different solutions, when feasible. But there are places where this is not feasible, where different answers are mutually incompatible. What then?
I would be very careful about practical consequences of Arrow theorem, because the theorem is mostly an artifact of static decision making. You shall read at least this paper:
https://www.annualreviews.org/docserver/fulltext/economics/13/1/annurev-economics-081720-114422.pdf?expires=1719337873&id=id&accname=guest&checksum=9DA7E4029B37B9A2AD9DADF1EA797D59
I also wrote this post presenting my own contributions:
https://www.lesswrong.com/posts/5wqFoHBBgpdHeCLS6/storable-votes-with-a-pay-as-you-win-mechanism-a
That can be interesting too.
>there is at least one decision rule (the majority rule) that guarantees that a well-defined social choice exists.
Is well-definedness the important criterion? I suppose there's not much point if the result lacks that property, but it seems far from sufficient.
>If establishing a consensus is one of the considerations that should determine which collective choice mechanism to adopt, it is not necessarily the only one. The collective decision process is also valuable in itself
Is this supposed to be obvious? I am puzzled by it. Since consensus is so difficult to achieve, I can understand if someone wants to abandon it and adopt some other guideline. I suppose I could argue for the proposition by imagining a thought experiment, where we had two candidate methods that both satisfied consensus. Then we might wish to compare them on other criteria. But that depends on eliminating the relevance of consensus first, which seems practically infeasible if not quite logically impossible.
> the choice of a collective choice mechanisms is also a social choice problem and all the points that Arrow has mentioned before also applies. To avoid an infinite regress, Arrow concludes that unanimity is needed at some point. We are thus back to square one, which is clearly not satisfactory.
This points to the relevance of consensus. It has the unusual property that there are no disputes that need to be resolved. If there was a dispute, that would indicate a lack of consensus. Perhaps we can reach consensus on the desirability of consensus? No, never mind.
>the possibility of making social choices that are justified and legitimate.
Isn’t consensus again the proper basis for justification and legitimacy? As long as there is dispute, this is in question. Since we cannot adopt the gods' perspective and just calculate the right answer, the second best is an answer no one thinks is worth changing. That might be either a good answer that is easy to change or a mediocre answer that is costly to change.
Perhaps subsidiarity is part of the answer. When there is dispute, disputants can apply different solutions, when feasible. But there are places where this is not feasible, where different answers are mutually incompatible. What then?
Very interesting. I look forward to your book.
Very nicely done. I think it must have surprised Arrow to see Rawls run with his framework and then reinscribe it into Knight’s