Random question I’ve been thinking about: how would you set up a market for votes? Suppose specifically that you have a proportional chances election (i.e. the outcome gets chosen with probability proportional to the number of votes cast for it—assume each vote is a distribution over candidates). So everyone has an incentive to get everyone who’s not already voting for their favorite option to change their vote; and you can have positive-sum trades where I sell you a promise to switch X% of my votes to a compromise candidate in exchange for you switching Y% of your votes to a compromise candidate.
What makes this complicated is that I don’t just care that I get votes for my favorite candidate, I also care about where those votes come from - i.e. would they otherwise have been cast for my second-favorite candidate, or for my least-favorite?
EDIT: oh, I think this is equivalent to impact certificates actually.
Some attempts:
Interesting! Hadn't thought of this approach. Let's see... Intuitively I think it gets pretty strategically weird because a) who you vote for depends pretty sensitively on other peoples' votes (e.g. in proportional chances voting you want to vote for everyone who's above the expected value of everyone else's votes; in approval voting you want to vote for everyone you approve of unless it bumps them above someone you like more), and b) you want to buy from your enemies much more than from your friends, because your friends will already not be voting for bad candidates. But maybe the latter is fine because if you buy from your friends they'll end up with more money which they can then spend on other things? I'll keep thinking.