Quadratic Voting

34 Pages Posted: 13 Feb 2012 Last revised: 19 Dec 2016

Steven P. Lalley

Department of Statistics, University of Chicago

E. Glen Weyl

Microsoft Research; Yale University

Date Written: December 16, 2016

Abstract

We propose Quadratic Voting (QV) as a method for binary collective decision-making: individuals buy votes for their preferred alternative, paying the square of the number of votes purchased. Quadratic cost uniquely makes the marginal cost proportional to votes purchased, encouraging voting proportional to the value and thus maximizing welfare. Similar heuristic arguments and experiments suggest it is more robust than other efficient mechanisms and it grows naturally from a variety of ideas in disparate literatures. Nonetheless, formal analysis beyond simple examples has proved illusive. By explicitly characterizing the subtle statistical structure of equilibrium, we prove convergence towards optimality in large populations in a canonical environment.

The online appendix for "Quadratic Voting" may be found here: http://ssrn.com/abstract=2790624.

Keywords: social choice, collective decisions, large markets, costly voting, vote trading

JEL Classification: D47, D61, D71, C72, D82, H41, P16

Suggested Citation

Lalley, Steven P. and Weyl, E. Glen, Quadratic Voting (December 16, 2016). Available at SSRN: https://ssrn.com/abstract=2003531 or http://dx.doi.org/10.2139/ssrn.2003531

Steven P. Lalley

Department of Statistics, University of Chicago ( email )

Eckhart Hall Room 108
5734 S. University Avenue
Chicago, IL 60637
United States

HOME PAGE: http://galton.uchicago.edu/~lalley/

Eric Glen Weyl (Contact Author)

Microsoft Research ( email )

641 Avenue of the Americas
7th Floor
New York, NY 10011
United States
(857) 998-4513 (Phone)

HOME PAGE: http://www.glenweyl.com

Yale University ( email )

28 Hillhouse Ave
New Haven, CT 06520-8268
United States

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