The 2016 US presidential election is likely unusually important, because Trump seems unusually likely to damage global coordination in ways that increase the risk of major wars – and to damage US political norms in ways that are likely to accelerate the decline of discourse and governance.

This is also an election in which the libertarian candidate has been unusually viable because he has any experience at all as a major government figure – despite his apparent lack of interest in the sorts of things a president needs to know about, such as other countries. Many people also want to register a protest vote with Green Party candidate Jill Stein, since they find Hillary Clinton's respectable establishment liberal misconstruals of the true and the good objectionable, and prefer disrespectable anti-establishment left-wing misconstruals of the true and the good.¹

Many people agree that Trump is terrible and it would be much less bad if Clinton wins, but some people prefer a third-party candidate and are unwilling to simply back the lesser of two evils. Some people end up favoring a vote for Clinton on net; others favor a third party vote. Both types are distributed over many states.

A protest vote has the same value anywhere. Federal funding also becomes available for any party that gets more than 5% of the popular vote – and it seems like Johnson's share of the vote could pass that threshold. On the other hand, due to the US electoral college system, the cost of forgoing a Clinton vote has very different effect depending on which state you're voting in. In a "safe state" overwhelmingly likely to go to one of the two major candidates, your vote has very little effect on the outcome of the election. But in a "swing state" where the outcome is more in doubt, your vote has a comparatively large effect on the outcome. Scott Aaronson points out that this distinction creates the opportunity for gains from trade, and has been promoting the idea of vote-swapping in order to reconcile these interests. The idea is that one or more Clinton supporters in safe states pledge to vote for a particular third-party candidate, in exchange for a third-party voter pledging to vote for Clinton.

In a one-to-one swap, this keeps third party national percentages the same, but increases the chance the swing state goes for the desired candidate. This is enough to yield gains from trade if both sides share a preference for one major-party candidate over the other. But even if that's not true, a many-to-one swap can still create gains from trade, by increasing both the chance that the desired major-party candidate wins, the third-party candidate's share of the vote total.

One of my friends recently suggested that we can't trust this system not to be gamed by Trump voters. I think that this is mistaken.

First, it conflates honor with other virtues, or just having a correct political opinion. You'd expect the virtues to be correlated and causally related in humans, to the extent that virtue ethics is about something real, but they're also conceptually distinct. I often observe someone with one virtue but not another. I think some very bad things of many Trump supporters - but unreliability on ordinary transactions is not one of them. (I can't say as much for Trump personally.)

Second, it's important to distinguish between cases where honor requires an active investment of effort, and cases where it's the default outcome.

When people are deciding whether to marry, it's easy for them to just not bother modeling their future selves, and their future willingness to keep their commitment, years in the future. Making a knowably false promise in this case doesn't require them to knowingly say something that contradicts their internal representation of the truth; they merely have to be lazy.

Vote swapping is about a specific, time-bounded action in the near future, so it's much easier for people to model their future selves in that case. When someone's mind already contains an internal representation of the truth, it takes an active investment of effort to say something to contradict that, and people generally don't want to do that unless they hate you a lot or they're a very naive act-utilitarian or they perceive themselves to have some very vital interest at stake like being able to feed their children.

I think there's a non-negligible chance of people lying, but I don't think that cuts down the value of vote-swapping by more than 50%. Voter power in safe states is lower than voter power in swing states by about two orders of magnitude, so even many-to-one vote-swapping still seems like a good deal. I also suspect that this is the sort of thing where we'd hear some of the less tight-lipped cheaters bragging about having cheated the system afterwards, if that behavior were at all common. Since I haven't heard much of that yet, I conclude that the system is trustworthy.

For reasons like this, I think it's important not to talk as if people were inherently untrustworthy in straightforward transactions like this one just because they have wrong politics, or as though it were ethical to cheat people when they're bad enough as people - because in both cases it erodes the potential for trades for the common good like this one.

About 45% of the US voting public thinks that the system is so corrupt that the closest thing to honesty they can hope for in a president is poor impulse control. But our society is not so far gone that people will routinely cheat one another in day-to-day transactions. I'm against hastening that transition - the longer it takes, the more time we have to build something better.

So I'm gonna put my safe-state California presidential vote to use and look for a vote-swap partner.