information:extraction, information:highlighting
Social choice theory is a branch of welfare economics that analyzes methods of combining individual opinions, beliefs, or preferences to reach a collective decision or create measures of social well-being. It contrasts with political science in that it is a normative field that studies how societies should make decisions, whereas political science is descriptive. Social choice incorporates insights from economics, mathematics, philosophy, political science, and game theory to find the best ways to combine individual preferences into a coherent whole, called a social welfare function. Because of its strong connections to political philosophy and voting, social choice is sometimes also called voting theory. Real-world examples include enacting laws under a constitution or voting, where individual preferences over candidates are collected to elect a person that best represents the group's preferences. The field is closely related to mechanism design, which can be thought of as modelling social choice with self-interested and potentially dishonest citizens; it thus involves the application of game theory. Social choice differs from decision theory in that the latter is concerned with how individuals, rather than societies, can make rational decisions.