The MIT Press NEWS Ma j o r i t y Ju d g m e n t Measuring, Ranking, and Electing

Mi c h e l Ba l i n s k i a n d Ri d a La r a k i

In Majority Judgment, Michel Balinski and Rida Laraki argue that the traditional theory of social choice offers no acceptable solution to the problems of how to elect, to judge, or to rank. They find that the traditional model—transforming the “prefer- ence lists” of individuals into a “preference list” of society— is fundamentally flawed in both theory and practice.

Balinski and Laraki propose a more realistic model. It leads to an entirely new theory and method—majority judg- ment—proven superior to all known methods. It is at once meaningful, resists strategic manipulation, elicits honesty, and is not subject to the classical paradoxes encountered in practice, notably Condorcet’s and Arrow’s. They offer theoretical, practical, and experimental evidence—from national elections to figure skating competitions—to sup- port their arguments.

Drawing on insights from wine, sports, music, and other competitions, Balinski and Laraki argue that the question should not be how to transform many individual rankings into a single collective ranking, but rather, after defining a common language of grades to measure merit, how to transform the many individual evaluations of each com- petitor into a single collective evaluation of all competi- tors. The crux of the matter is a new model in which the traditional paradigm—to compare—is replaced by a new paradigm—to evaluate.

Michel Balinski is Directeur de Recherche de classe exceptionnelle (Emeritus), C.N.R.S. and the Laboratoire d’Econométrie, Département d’Économie, École Polytechnique, Palaiseau, . Rida Laraki is Chargé de Recherche de première classe, C.N.R.S., Laboratoire d’Econométrie, Professeur, Département d’Économie, École Polytechnique, Palaiseau, France, and Chercheur Associé, Équipe Combinatoire et Optimisation, Université Pierre et Marie Curie, Paris, France.

March 2011 • 448 pp., 2 figures., $40 cloth • 978-0-262-01513-4

Available at bookstores or online at http://mitpress.mit.edu/9780262015134 Ma j o r i t y Ju d g m e n t Measuring, Ranking, and Electing

Mi c h e l Ba l i n s k i a n d Ri d a La r a k i

“The authors have proposed a very interesting voting method to rem- “This could be the most important work on the problem of collective edy the well-known defects in standard methods, such as plurality choice since 1951, or even since 1785. It is written with wit and preci- voting. It requires the voters to express their preferences in a simple sion, and, fittingly for work done in France, it shows that wine judges and easily comprehensible way, and the authors supply evidence that have come closest to finding practical solutions to the problem.” the candidate chosen by their methods is a reasonable selection. This — Iain McLean, Professor of Politics, University of Oxford work may well lead to a useful transformation in election practice.” — Kenneth J. Arrow, Joan Kenney Professor of and Pro- “Majority Judgment is a work of astonishing originality, with remarkable fessor of , Emeritus, Stanford University; Nobel depth and range. The authors rethink in fundamental ways the theory of laureate in Economics (1972) social choice, recasting it on the basis of evaluations rather than prefer- ences. It will appeal to mathematicians, philosophers, and economists “Michel Balinski has done it again! He has produced—this time with interested in the abstract theory of social choice; political scientists and Rida Laraki—a beautiful, comprehensive, conceptually deep, and ut- election reformers looking for better methods of voting; psychologists, terly sound treatise on the mechanics of democracy. By no means an educators, and measurement theorists; and officials of organizations abstruse, ivory-tower exercise in pure math, the work is supported by (such as the Olympics) who want to improve any competition evaluated a plethora of in-depth empirical analyses taken from real life. Most by subjective judgments rather than objective measures.” important, the book introduces a vital new idea that promises to rev- — Jack Nagel, Steven F. Goldstone Endowed Term Professor of Politi- olutionize democratic decision making: ‘judging’ rather than voting. cal Science, University of Pennsylvania Enjoy—while learning.” — , Professor Emeritus of , Center for “This is an important book destined to provoke considerable contro- Rationality, The Hebrew University of Jerusalem; Nobel laureate in versy. Inspired by a deep understanding of practice—ranking students, Economics (2005) skaters, wines—it goes beyond impossibility theorems to constructive- ly challenge the dominant approach to the design of voting procedures “Finding a way to consolidate the different views of many individuals with a new theory, supported by extensive experimental evidence.” into a single outcome is a fundamental problem common to areas as — Martin Shubik, Seymour Knox Professor Emeritus of Mathematical diverse as voting for president or judging skaters. When the individ- Institutional Economics, ual views are expressed as rankings the Arrow impossibility theorem shows that any method must always lack many desirable properties. In contrast, in this revolutionary book, Balinski and Laraki show that “It is only rarely that a book breaks major new ground in a field, and when the individual views are expressed as grades, not rankings, sim- this is one of those books. I am confident that it will be regarded as ple and practical methods do exist, and they describe them.” a classic—one that will be widely read for decades to come. I also expect that it will help open up an entirely new research agenda in — Ralph E. Gomory, New York University; President Emeritus, Alfred P. social choice theory and practice.” Sloan Foundation; former Senior Vice President for Science and Tech- nology, IBM; National Medal of Science laureate — John A. Weymark, Professor of Economics, Vanderbilt University; former President, Society for Social Choice and Welfare

“Balinski and Laraki propose an intriguing new voting method for po- litical elections: have voters ‘grade’ the candidates and elect the one “In this path-breaking book, Balinski and Laraki make the case for a having the highest median grade. The method will be controversial fundamentally new approach to voting, in which voters evaluate can- but deserves careful consideration.” didates in terms of a common language rather than simply ranking them. This is a highly original work that challenges traditional social — Eric S. Maskin, A. O. Hirschman Professor of Social Science, Institute choice theory and has important implications for the design of real- for Advanced Study; Nobel laureate in Economics (2007) world electoral systems.” — H. , James Meade Professor of Economics, University of Oxford

Available at bookstores or online at http://mitpress.mit.edu/9780262015134