Do not vote third-party
| ℹ️️️ This is a comment on US politics. I live in Australia. |
Many US voters are unsatisfied with the two-party system. This post has nothing to do with specific voting preferences, but rather on rational voting within this system.
Most US elections are winner takes all. Third-party supporters are therefore faced with a dilemma: support their party with an inconsequential vote, or vote for the least bad two-party candidate.
This is a basic collective action problem. If all the supporters acted rationally, no votes would be wasted and the third-party would win (or at least the two-party system would start to crack).
In practice, voters don’t act monolithically, and so some supporters stick it out while others chicken out. Therefore the strategy is to grow support until the party becomes viable. Votes are wasted in the short-term, but have some potential to win a future election by persuading other supporters.
Is this strategy feasible? Technically yes. It would take a long time and the opportunity cost would be massive, but you could waste millions of votes on hundreds of elections and eventually break the two-party system.
Is it worth it? This depends on the expected utility of each party. If the third-party supporters expect the third-party to be massively favourable over the major parties, then there is no other option. If they expect the third-party to only be marginally better than the least bad party, then wasting votes becomes more wasteful.
Is it sustainable? Probably not. Even when you finally elect a third-party, the rules of the game don’t change. You’ve merely influenced the behaviour of the players.
But America isn’t a game theory puzzle. There are some real-world variables that are missing from this equation. Rules can be changed.
Remember when I said most US elections are winner takes all? This is because they use a first-past-the-post (FPP) voting system. In this system, whoever gets the most votes wins. Your third-party vote is wasted because you’re forced to choose a single candidate when you really wanted to express your preferences.
But there are several US elections which use ranked-choice voting (RCV)! In fact one of the most important US elections of this year, the 2025 NYC Democratic mayoral primary, used RCV. In Australia, we call this preferential voting, and we use it for almost all of our elections.
RCV would allow American voters to support minor parties without wasting their vote. In the 2016 US presidential election, over 7 million votes were wasted in an election with a margin of 3 million votes.
RCV changes the game rather than the outcome of a few matches. Voting for third parties in a two-party system is like bringing a baseball bat to a basketball game.
How does this change our strategy for US voters who are unsatisfied with the two-party system? Well, now the goal is to introduce RCV instead of winning elections. But even if you just wanted to win elections, a ranked-choice vote is the only realistic way of achieving this. In fact, passing RCV legislation is probably more likely than electing a third-party. Therefore your strategy should actually be to vote for the two-party candidate more likely to introduce RCV!
