Comparison of Public Choice Systems

The area of social decision-making is one in which the disciplines of game theory, political science, and economics all meet. One of the simplest decisions to be faced is the election of one candidate from several. Various voting systems have been proposed for such elections. In order to compare these systems in terms of their tendency to elect a candidate representative of the voters' preferences, a measure of "effectiveness" has been developed. The study of the effectiveness of voting systems is continued in this paper. In particular, two families of voting systems are found to contain three- and four-candidate systems which are more effective than any previously discussed. Voting systems can be compared in terms of their effectiveness in representing the preferences of the voters. Several generalizations of the standard voting system (in which each voter casts a single vote) are considered, as in the Borda system (in which the candidates receive votes proportional to the ranks assigned them by the voters). For elections involving three or more candidates, it is found that the Borda voting system is markedly more effective than the standard system. For many-candidate elections, the Borda system is essentially as effective as any voting system can be.