An Introduction to Social Choice
Maxwell L. Stearns
University of Maryland Francis King Carey School of Law
March 7, 2009
EDGAR HANDBOOK ON PUBLIC CHOICE, Dan Farber and Anne O'Connell, eds., Edgar Publishing Company, 2009
U of Maryland Legal Studies Research Paper No. 2009-15
Social choice studies the differing implications of the concept of rationality (or transitivity) for individuals versus groups under specified conditions and the significance of these differences in various institutional decision making contexts. This introductory chapter on social choice for the Elgar Handbook on Public Choice (Elgar Publishing Company, Dan Farber and Anne O'Connell, editors), introduces the basic framework of social choice, considers the implications of social choice for various legal and policy contexts, and provides a framework for evaluating a range of normative proposals grounded in social choice for reforming lawmaking institutions.
After a brief introduction, part II introduces the following concepts: cycling, the median voter theorem, the Condorcet criterion, path dependence, agenda setting, minimum winning coalitions, multipeakedness, dimensionality, symmetry and Arrow's Theorem. This part then describes several notable voting protocols that have been offered in the literature to ameliorate identified deficiencies in aggregating collective preferences, including Borda Counts, Coombs Voting, Hare Voting (or Single Transferable Voting), Copeland Voting, Plurality Voting and Approval Voting. Part III presents prominent normative proposals advanced by legal scholars relying upon, or calling into question, the discipline of social choice, including proposals to change electoral voting procedures; to modify doctrines affecting judicial deference to legislative bodies; and to alter various voting protocols in legislatures and appellate courts, including most notably the Supreme Court. Part IV will rely upon social choice to present a framework for reassessing several of the normative proposals described in part III, along with some of the critical commentary. This part recasts social choice, and in particular Arrow's Theorem, into a set of positive tools that can be used to respond to some of these proposals and to provide insights into how various institutions operate individually and in combination with other lawmaking institutions. The analysis explains the important role of institutional complementarity in improving the quality and rationality of institutional outputs. This part will also introduce several related concepts including the fallacy of composition, the isolation fallacy, and the nirvana fallacy, and apply these concepts to the various proposals and responses considered in part III. Part V revisits Arrow's Theorem and uses the rationality and fairness criteria as a means through which to compare institutions, with a particular focus on Congress and the Supreme Court. The chapter concludes with some suggestions for future social choice research related to law and lawmaking institutions.
Number of Pages in PDF File: 88
Keywords: median voter theorem, Condorcet criterion, path dependence, agenda setting, minimum winning coalitions, multispeakedness, dimensionality, symmetry, Arrow's Theorem
Date posted: April 22, 2009