Utilitarian Voting is a single winner election method design to satisfy Jeremy Bentham's Principle of Utility. This principle can be stated as "Act always to promote the greatest happiness for the greatest number." That was how Bentham had stated it. It is also called Happiness Voting.
Each voter is given a list of all candidates in the election. The voter is asked to list the candidates that they are happy with to win the election. A given voter can only list a given candidate once. Whichever candidate occurs on the most lists wins.
This voting system is also called approval voting. It is said to satisfy Bentham's principle by electing the candidate that makes the greatest number of voters happy. A criticism of this voting system is that it only tries to make the greatest number of voters happy. It does not take into account the extent of happiness. Social utility efficiency calculations show that the most utilitarian of the common voting methods, if we consider the degree of happiness rather than an arbitrary binary "happy/unhappy" metric, is Range Voting. Some sample social utility efficiency calculations expressed as voter satisfaction ratios (the percentage of the total ideal utility achieved - not the percent of satisfied voters):
Utility measurements: Group A: 5 candidates, 20 voters, random utilities; Each entry averages the results from 4,000,000 simulated elections. Group B: 5 candidates, 50 voters, utilities based on 2 issues, each entry averages the results from 2,222,222 simulated elections.
Voting system - VSR A - VSR B
Magically elect optimum winner 100.00% 100.00% Range (honest voters) 96.71% 94.66% Borda (honest voters) 91.31% 89.97% Approval (honest voters) 86.30% 83.53% Condorcet-LR (honest voters) 85.19% 85.43% Range & Approval (strategic voters) 78.99% 77.01% IRV (honest voters) 78.49% 76.32% Plurality (honest voters) 67.63% 62.29% Borda (strategic exaggerating voters) 53.26% 51.78% Condorcet-LR (strategic voters) 42.56% 41.31% IRV (strategic exaggerating voters) 39.07% 39.21% Plurality (strategic voters) 39.07% 39.21% Elect random winner 0.00% 0.00%