Since the 1960s, the most common rule used for electing presidents worldwide has shifted from plurality (first-past-the-post) to majority runoff (a requirement for a second round between the top two candidates if no candidate wins 50 percent of the vote). Between 1990 and 2016 in Latin America, levels of democracy improved in most countries under runoff but plummeted in most countries under plurality. Runoff lowered barriers to entry for new parties. It also ensured that the president had majority support and enticed candidates toward the political center. While the concerns many scholars have expressed about the proliferation of political parties under runoff is not unwarranted, this issue can be mitigated through additional institutional innovations.