Quadratic voting

From Wikipedia, the free encyclopedia
Jump to navigation Jump to search

Quadratic voting (sometimes abbreviated QV) is a collective decision-making procedure, where participants cast their preference and intensity of preference for each decision (as opposed to a simple for or against decision).[1]

According to its authors Steven P. Lalley and E. Glen Weyl, Quadratic voting is claimed to achieve the greatest possible good for the greatest number of group members[2] although other proponents of Quadratic Voting admit that is at best an approximation[3]. It addresses issues of voting paradox and majority-rule.

Based on market principles, each voter is endowed with a budget of “voice credits” that they may spend influencing the outcome of a range of decisions. If a participant has a strong preference for or against a particular decision, additional votes can be allocated. A vote pricing rule determines the cost of additional votes, whereby each vote increasingly becomes more expensive.

The quadratic nature of the voting means that a voter can use his or her votes more efficiently spread across many issues. For example a voter with a budget of 16 vote credits can apply 1 vote credit to each of 16 issues. But if they feel strongly about a single issue and apply 4 votes at the cost of 16 credits to a single issue. This will use their entire budget. This also means there is a large incentive to buy and sell votes, although using a strictly secret ballot gives some protection against vote buying as the purchase cannot be verified.

Vote Pricing Example
Number of votes “Voice Credit” cost
1 1
2 4
3 9
4 16
5 25


  1. ^ Lalley, Steven; Weyl, E. Glen (2017-12-24). "Quadratic Voting: How Mechanism Design Can Radicalize Democracy". Rochester, NY. doi:10.2139/ssrn.2003531.
  2. ^ "Quadratic Voting". collectivedecisionengines.com. Retrieved 2018-05-22.
  3. ^ Posner, Eric; Weyl, E. Glen (2018). Radical Markets: uprooting capitalism and democracy for a just society. Princeton. ISBN 9780691177502. OCLC 1030268293.

Further reading[edit]

  • US Patent 9754272, E Glen Weyl; David Quarfoot & Eric Posner et al., "System and Method for Quadratic, Near-Quadratic, and Convex Voting in Various Types of Research and Voting", issued 5 September 2017