Author: Roger D. Congleton
Source: Entries for The Encyclopedia of Public Choice, C. K. Rowley and F. Schneider, Ed.s Kluwer Academic Press (2003).
This is a survey of the median voter model which is regarded as one of the simplest models of public policy formation (the other one is the dictatorship model). Primary and medium readers will find that the author provides a clear and readable account for this important concept. I believe that advanced readers will not disappointed with it because the author devotes more attention to explain the idea of this model rather than only profound formalization. The former is more important and helpful for any one who really wants to understand this model. In the reference you can find the literatures if necessary. To the author, the median voter model “can be regarded not only as a convenient method of discussing majoritarian politics and a fruitful engine of analysis, but also a fundamental property of democracy”. After a brief introduction of its history the author explains his idea from three aspects.
1. the positive aspect of the model
From the positive perspective, the median voter model functions as the counterpart of the competitive model which serves the micro economics literature. The author develops his illustration step by step. Firstly, he explains the meaning of weak form and strong form of median voter model respectively in a direct democracy setting. Secondly, he expounds the same issue in electoral setting. Thirdly, taking the median voter’s preferred level of environmental regulation as an example, the author concludes that the median voter model has great potential in modeling government policies. Lastly, the author gives policy implication of the median voter model. These policy implication make it easy for us to understand such questions that why public polices will tend to be moderate middle-of-the-road policies, why most people will be at least partly displeased with the policies chosen, why median voter policies tend to be relatively stale through time, and so forth. All of the above steps are organized by the fundamental issues which are alike in positive microeconomics. For instance, while considering the median voter model, people still want to know whether or not there is an equilibrium result? If yes, then is this kind of equilibrium stable? If no, then why it is so?
2. the normative aspect of the model
From the normative perspective, we should understand that although the median voter gets what he or she wants, it doesn’t imply that public policy will be efficient in the usual Paretian sense of welfare economics. The reasons include: 1) Majoritarian policy is likely to impose externalities on the minority 2) Even within the majority, votes rather than the intensity of desire or willingness to pay determine policy in electoral setting. In such case, unrealized gains to trade may exist at the median voter’s ideal policy. 3) In cases where the policy information available to the median voters is fairly limited, the median voter will not get what truly advances his or her interests. 4) Voter ignorance opens the door to the strategic games of interest groups and the bureaucrats who may manipulate voters in policy areas where the median voters is unlikely to be well informed.
3. the theoretical issue of the model
The most important theoretical issue with majority rule is that a median voter does not exist. From this point, I’d like to raise 2 questions concerning the thesis of this paper. They are as follows:
1) If voting paradox is unavoidable, how do we make differences between democracy and nondemocracy?
2) How to understand the effort of looking for the only existence of political equilibrium under the circumst
ance of the median voter model?
Ma Qun