As James Buchanan artfully defined it, public choice is “politics without romance.” The wishful thinking it displaced presumes that participants in the political sphere aspire to promote the common good. In the conventional “public interest” view, public officials are portrayed as benevolent “public servants” who faithfully carry out the “will of the people.” In tending to the public’s business, voters, politicians, and policymakers are supposed somehow to rise above their own parochial concerns.
In modeling the behavior of individuals as driven by the goal of utility maximization—economics jargon for a personal sense of well-being—economists do not deny that people care about their families, friends, and community. But public choice, like the economic model of rational behavior on which it rests, assumes that people are guided chiefly by their own self-interests and, more important, that the motivations of people in the political process are no different from those of people in the steak, housing, or car market. They are the same human beings, after all. As such, voters “vote their pocketbooks,” supporting candidates and ballot propositions they think will make them personally better off; bureaucrats strive to advance their own careers; and politicians seek election or reelection to office. Public choice, in other words, simply transfers the rational actor model of economic theory to the realm of politics.
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James M. Buchanan is one of the fathers of public choice theory. He is a brilliant writer and a great thinker - though in terms of adulation, I would not go quite as far as some of the contributors in the below clip. Buchanan can be rather wordy, non-incisive (though one of the best writers I have ever come across), and a bit too wedded to neoclassic economics. But who am I, to criticise a giant.