This year’s election campaigns have only just started, but if you’re anything like most American voters, you can already rule out the few candidates whose positions are actually closest to yours. The reason? You just might be misled by a popular voting fallacy deeply entrenched in our political culture.

You probably don’t agree with the Republican or Democratic Party on everything. After all, their positions aren’t logically connected: just because you agree with them on one issue doesn’t give you any reason to agree with them on another. (What’s the logical connection between supporting same-sex marriage and opposing school vouchers? Opposing abortion and supporting the farm bill?) Luckily for you, however, the Republican and Democratic parties aren’t the only two games in town. There are dozens of ballot-qualified political parties around the country—the Moderate Party, American Reform Party, Justice Party, Women’s Equality Party—and it’s likely that at least one of these minor parties will match your views more closely than the either of the two major ones.

Many Republican voters of our generation, for example, have views that really align more closely with the Libertarian Party than with the socially traditionalist Republican Party. Similarly, many younger Democratic voters actually turn out to be closer to the Green Party, which has basically the same positions as the Democratic Party on all the major issues, but places a higher priority on environmental issues like climate change. Yet even though there are many third-party candidates who match most voters’ views more closely than either the Republican or Democratic candidates, very few people end up voting third party, and for largely the same, familiar reasons.

In the last two years, who has not heard “I honestly would have preferred a third-party candidate to Hillary [or Trump], but we just can’t let Trump [or Hillary] win, so I’m not going to throw away my vote to a third-party candidate who we know doesn’t stand a chance of winning.” This is a very popular view, but unfortunately it is also, as economists can tell you, fallacious.

In national elections, economists and some political scientists who consider such issues say, your one vote makes effectively zero difference, so it’s irrational to vote for the purpose of shaping the election’s outcome. It to speak of a “wasted vote,” because your vote wouldn’t have mattered anyway. This doesn’t necessarily mean you shouldn’t vote at all, since there are powerful moral reasons to vote. But it does mean that if your goal is to influence the outcome of the election, then voting third party, voting major party, and not voting are equally rational in economic (in the sense of strictly self-interested) terms.

The common objection, of course, is that your vote does matter, because if everyone agreed that voting was irrational and didn’t vote, then voter turnout would be even more dismal than current levels. However, the impact of your individual vote doesn’t increase with the addition of other votes. Besides, a third-party voter could respond that if everyone were equally rational, a third-party candidate would win every time!

There are two possibilities: your vote makes a significant difference to the outcome or it doesn’t. If it does, then by voting third party you will make a significant difference—you won’t be wasting your vote. If it doesn’t, then you are still not wasting your vote, since it doesn’t matter anyway.

Voting isn’t exactly rocket science, but that doesn’t mean . As the midterms approach, let’s keep those famous words of Hunter S. Thompson in mind: “anything worth doing, is worth doing right.”