As Ned Foley and I have been writing about in various forums, our typical use of plurality voting rules in the US can lead to factional candidates winning nominations or elections, even though they lack majority support. That’s one of the arguments for ranked-choice voting, which is a means of enabling in a single voting process a winner to emerge who has the broadest support.

In light of that, I wanted to flag these findings in a new draft paper on the voting rules countries use to elect presidents. The paper, by Adam Prezworski, Jose Cheibub, and Fernando Limongi, was presented at a conference I participated in at the University of Chicago. They find that when countries shifted to direct election for their presidents, they all initially used a single-round of voting with a plurality winner rule. The idea of a two-round election had not yet been invented. But once the idea developed of a two-round voting system if no candidate received a majority in the first round, the two-round system became widespread.

After World War II, there was a dramatic shift to two-round presidential elections, if no candidate received a majority in the first round. Most famously, the French adopted this system in 1962, with its first use occurring in the 1965 election. Today, of the countries that directly elect a president, about 60% use the two-round runoff election system. A few countries that use it do not require a candidate to reach the majority in the first round; in Costa Rica, for example, a plurality over 40% is enough in the first round to be elected.

In the American context, turnout in the second round in states that use runoff elections tends to drop significantly. We know that in France, that is not the case: turnout in the second round of their presidential elections typically exceeds that in the first round. The draft paper does not have data on turnouts in other countries in their second round vote. The paper also does not provide a lot of information on why countries shifted so dramatically after World War II from one round, plurality voting to two round, majority winner systems, though my assumption would be the risk of factional candidates capturing the presidency became a much greater concern after WW II.