Majority Rule in the World's Democracies
Majority rule through IRV or majority runoffs are the standard in modern democracies. In the following chart, out of 28 international presidential elections studied, 21 require a majority winner. Only 4 require a plurality, and only 3 use another method. Of those three, at least one, the United States has no majority requirement in presidential elections in terms of popular vote.

[ 2006 majority presidential elections in Chile, Finland and Haiti ]

County Runoff Plurality Other

Mod. DCR
Austria MR

Benin MR

Brazil MR

Bulgaria MR

Chile MR

Costa Rica

Mod. MR
Croatia MR

Dominican Republic MR

Finland MR

France MR

Ghana MR

Ireland IRV

Korea, South
Lithuania MR

Mali MR

Mongolia MR

Namibia MR

Poland MR

Portugal MR

Romania MR

Slovakia MR

Slovenia MR

United States

Uruguay MR

Total 21 4 3

MR: Majority Runoff (denominator used to calculate the absolute majority threshold [50%]
ranges from valid votes, to all votes, to registered voters).
PL: Plurality (First Past the Post).
IRV: Instant runoff voting.
Mod DCR: 45% threshold, or 40% and 10% more than the #2 candidate, to avoid a runoff.
Mod. MR: 40% threshold to avoid a runoff.
EC: Electoral College.

Source: Mark P. Jones, Associate Professor of Political Science, Rice University.