Newswise — Recently, The Washington Post and ABC News annual poll found that, for the first time in its history, the two leading candidates for president — Democrat Hillary Clinton and Republican Donald Trump — are viewed unfavorably by a majority of the voting public. Meanwhile, Green Party leader Jill Stein has called on Bernie Sanders to collaborate with her on a third-party ticket. But what would an election with three viable candidates do to election math?
“The American system of voting is simple and understandable,” explains Sam Smith, Ph.D., professor and chair of mathematics at Saint Joseph's University. “Generally, voters choose between two major candidates, and the one with the most votes will win. But, if three or four people are in the race, problems arise.”
Smith, the author of Chance, Strategy and Choice: An Introduction to the Mathematics of Games and Elections, points out that any election with more than two contestants is likely to end with a winner who has received far fewer than a majority of the votes.
“If a winning candidate earns 40 percent of the vote and the remaining 60 percent is split evenly between the others, it’s possible that more voters chose against the winner than for him or her,” Smith says.
An alternative method of voting, called “approval voting,” could eliminate this possibility, according to Smith. In this system, electors could vote in favor of any number of candidates. In this system, a winning candidate is more likely to have the approval of a majority of voters.
According to Smith, the approval system would also help prevent the “spoiler effect” in an election with more than two candidates by allowing voters to express their preferences without worrying about splitting their vote.
“When you agree with more than one candidate on certain issues, approval voting lets you express that agreement without needing to worry whether voting for one takes votes away from the other, lowering both their chances of winning,” Smith says. “It lets electors add some extra strategy to the way they vote.”
Smith can be reached for comment at 610-660-1559 or email@example.com, or by calling University Communications at 610-660-3223.