Revisiting Nobel Prize Winning Economic Theories
Public choice takes the same principles that economists use to analyse people's actions in the marketplace and applies them to people's actions in collective decision making. Economists who study behavior in the private marketplace assume that people are motivated mainly by self-interest. Although most people base some of their actions on their concern for others, the dominant motive in people's actions in the marketplace—whether they are employers, employees, or consumers—is a concern for themselves. Public choice economists make the same assumption—that although people acting in the political marketplace have some concern for others, their main motive, whether they are voters, politicians, lobbyists, or bureaucrats, is self-interest. In Buchanan's words the theory "replaces... romantic and illusory... notions about the workings of governments [with]... notions that embody more skepticism."
In the past many economists have argued that the way to rein in "market failures" such as monopolies is to introduce government action. But public choice economists point out that there also is such a thing as "government failure." That is, there are reasons why government intervention does not achieve the desired effect.
One of the chief underpinnings of public choice theory is the lack of incentives for voters to monitor government effectively. Anthony Downs, in one of the earliest public choice books, An Economic Theory of Democracy, pointed out that the voter is largely ignorant of political issues and that this ignorance is rational.
Public choice economists point out that this incentive to be ignorant is rare in the private sector. Someone who buys a car typically wants to be well informed about the car he or she selects. That is because the car buyer's choice is decisive—he or she pays only for the one chosen. If the choice is wise, the buyer will benefit; if it is unwise, the buyer will suffer directly. Voting lacks that kind of direct result. Therefore, most voters are largely ignorant about the positions of the people for whom they vote. Except for a few highly publicized issues, they do not pay a lot of attention to what legislative bodies do, and even when they do pay attention, they have little incentive to gain the background knowledge and analytic skill needed to understand the issues.
Reference: Jane S. Shaw, Public Choice Theory, The Concise Encyclopaedia of Economics 2007