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The Moderating Effect of Instant Runoff Voting

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  • Kiran Tomlinson
  • Johan Ugander
  • Jon Kleinberg

Abstract

Instant runoff voting (IRV) has recently gained popularity as an alternative to plurality voting for political elections, with advocates claiming a range of advantages, including that it produces more moderate winners than plurality and could thus help address polarization. However, there is little theoretical backing for this claim, with existing evidence focused on case studies and simulations. In this work, we prove that IRV has a moderating effect relative to plurality voting in a precise sense, developed in a 1-dimensional Euclidean model of voter preferences. We develop a theory of exclusion zones, derived from properties of the voter distribution, which serve to show how moderate and extreme candidates interact during IRV vote tabulation. The theory allows us to prove that if voters are symmetrically distributed and not too concentrated at the extremes, IRV cannot elect an extreme candidate over a moderate. In contrast, we show plurality can and validate our results computationally. Our methods provide new frameworks for the analysis of voting systems, deriving exact winner distributions geometrically and establishing a connection between plurality voting and stick-breaking processes.

Suggested Citation

  • Kiran Tomlinson & Johan Ugander & Jon Kleinberg, 2023. "The Moderating Effect of Instant Runoff Voting," Papers 2303.09734, arXiv.org, revised Jan 2024.
  • Handle: RePEc:arx:papers:2303.09734
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    1. Ohtsubo, Yohsuke & Rapoport, Amnon, 2006. "Depth of reasoning in strategic form games," Journal of Behavioral and Experimental Economics (formerly The Journal of Socio-Economics), Elsevier, vol. 35(1), pages 31-47, February.
    2. Chamberlin, John R. & Cohen, Michael D., 1978. "Toward Applicable Social Choice Theory: A Comparison of Social Choice Functions under Spatial Model Assumptions," American Political Science Review, Cambridge University Press, vol. 72(4), pages 1341-1356, December.
    3. McGann, A J & Grofman, Bernard & Koetzle, W, 2002. "Why Party Leaders Are More Extreme Than Their Members: Modeling Sequential Elimination Elections in the U.S. House of Representatives," Public Choice, Springer, vol. 113(3-4), pages 337-356, December.
    4. Donald Horowitz, 2007. "Where have all the parties gone? Fraenkel and Grofman on the alternative vote – yet again," Public Choice, Springer, vol. 133(1), pages 13-23, October.
    5. Massimo Bordignon & Tommaso Nannicini & Guido Tabellini, 2016. "Moderating Political Extremism: Single Round versus Runoff Elections under Plurality Rule," American Economic Review, American Economic Association, vol. 106(8), pages 2349-2370, August.
    6. Peter M. DeMarzo & Dimitri Vayanos & Jeffrey Zwiebel, 2003. "Persuasion Bias, Social Influence, and Unidimensional Opinions," The Quarterly Journal of Economics, President and Fellows of Harvard College, vol. 118(3), pages 909-968.
    7. Samuel S. -H. Wang & Jonathan Cervas & Bernard Grofman & Keena Lipsitz, 2021. "A systems framework for remedying dysfunction in U.S. democracy," Papers 2106.11901, arXiv.org, revised Aug 2021.
    8. Anthony Downs, 1957. "An Economic Theory of Political Action in a Democracy," Journal of Political Economy, University of Chicago Press, vol. 65(2), pages 135-135.
    9. Dellis, Arnaud, 2009. "Would letting people vote for multiple candidates yield policy moderation?," Journal of Economic Theory, Elsevier, vol. 144(2), pages 772-801, March.
    10. Jon Fraenkel & Bernard Grofman, 2004. "A Neo-Downsian Model of the Alternative Vote as a Mechanism for Mitigating Ethnic Conflict in Plural Societies," Public Choice, Springer, vol. 121(3), pages 487-506, February.
    11. Martha Kropf, 2021. "Using Campaign Communications to Analyze Civility in Ranked Choice Voting Elections," Politics and Governance, Cogitatio Press, vol. 9(2), pages 280-292.
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