by Tyler Cowen
Ranked choice voting is on many state and local ballots this year, so it’s worth considering how it works in practice. Or, as we economists like to say: It’s time for some game theory.
There are many ways to run a ranked choice system, but they all basically allow voters to list candidates by order of preference. An algorithm then turns those rank orderings into a winner.
Typically, if one candidate wins a majority of first-place votes, the election is called. If no one gets more than 50% of the votes, the candidate with the fewest votes is eliminated, and votes for that candidate are reallocated to his or her voters’ second choices. This process is repeated until a winner emerges.
That may sound complicated. But the system has proved workable so long as voters rank the candidates in order of true preference. Alaska and Maine currently use forms of ranked choice voting, and local elections in New York City use a comparable system. Ireland is the most notable international example.
Come November, Idaho, Nevada and Oregon voters will decide whether those states will switch to ranked choice methods. Missouri, meanwhile, is considering banning the system.
One common criticism of ranked choice voting is that it confuses voters. Another is that more sophisticated voters might try to game the system, for instance by giving low ranks to candidates who are their favorite’s biggest rivals, rather than listing the candidates by order of actual and sincere preference.
These criticisms are not irrelevant. But they are not the most significant effects of the system.
Game theory can help explain how ranked choice voting changes the behavior of candidates, as well as the elites who support them. Consider a ranked choice election that has five or six candidates. To win the election, you can’t just appeal to your base. You also can’t alienate your opponent’s base. You want supporters of other candidates to regard you as “not too bad,” because if they hate you, they could rank you very low and get you tossed out of the running quickly.
Candidates are thus encouraged to moderate their positions and their behavior — that is, not to call each other too many names. If the favorite candidate of one voter calls the favorite of another “weird,” for example — to choose an example not quite at random — the latter voter might respond by voting down the name-caller to the very bottom.
The result? Negative campaigning diminishes, and politics moderates. The effect can be especially pronounced in party primaries, which sometimes are dominated by the most extreme voters.
The candidates also compete in different ways. In particular, they try to outdo each other when it comes to constituency service, which is a way of being popular without offending anybody.
The broader evidence on ranked choice voting shows that, when used, it has made U.S. politics more moderate. Alaska’s ranked choice voting helped moderate Republican Lisa Murkowski beat her more ideological opponents in 2022. In Idaho, some conservatives regard ranked choice voting with suspicion, fearing it is a plot to neutralize their influence.
In Ireland, politics is fairly non-ideological on most matters of policy, and elections are not typically seen as major, course-altering events. After more than a century with this system, the Irish seem happy to keep it.
The lesson here is that it is not possible to evaluate ranked choice voting in the abstract. It usually makes politics less extreme and less ideological, but those are descriptive terms, not normative ones. I would prefer California’s politics to be less ideological, for example, but that is because it embodies an ideology distinct from mine. And sometimes the more extreme and ideological positions are entirely correct, as for instance John Stuart Mill’s advocacy of women’s suffrage and birth control in the 19th century.
In general, ranked choice voting is best for places where voters feel things are already on the right track and ought to stay there. It is a voting system for the self-satisfied. Which parts of contemporary America might that describe? No voting method yet devised can settle that question.
