Comparing Voting Methods: 2016 US Presidential Election

Before the 2016 US presidential elections, more than 2,000 participants participated to a survey in which they were asked their opinions about the candidates, and were also asked to vote according to different alternative voting rules, in addition to plurality: approval voting, range voting, and instant runoff voting. The participants were split into two groups, a first one facing a short set of four candidates (Clinton, Trump, Johnson and Stein), and a second one facing a long set of nine candidates (the previous four plus Sanders, Cruz, McMullin, Bloomberg, and Castle). The paper studies three issues: (1) How do U.S. voters effectively use these alternative rules? (2) What kind of candidates, in terms of individual preferences, is favored by which rule? (3) Which rules empirically satisfy the independence of irrelevant alternatives? Our results evidence that Bernie Sanders stands out as the “best” candidate in terms of individual preferences (using any standard criterion), and that evaluative voting rules such as approval voting and range voting might lead to this outcome, contrary to direct plurality and instant runoff voting (that elects Clinton) and to the official voting rule (that elected Trump)