Abstract
In this paper we show that in a simple spatial model where the government is chosen under strict proportional rule, if the outcome function is a linear combination of parties’ positions, with coefficient equal to their shares of votes, essentially only a two-party equilibrium exists. The two parties taking a positive number of votes are the two extremist ones. Applications of this result include an extension of the well-known Alesina and Rosenthal model of divided government as well as a modified version of Besley and Coate’s model of representative democracy.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Alesina A, Rosenthal H (1995) Partisan politics, divided government, and the economy. Cambridge University Press, Cambridge
Alesina A, Rosenthal H (1996) A theory of divided government. Econometrica 64:1311–1341
Alesina A, Rosenthal H (2000) Polarized platforms and moderate policies with checks and balances. J Public Econ 75:1–20
Austen-Smith D (2000) Redistributing income under proportional representation. J Polit Econ 108:1235–1269
Austen-Smith D, Banks J (1988) Elections, coalitions, and legislative outcomes. Am Polit Sci Rev 82:405–422
Baron DP, Diermeier D (2001) Elections, governments, and parliaments in proportional representation systems. Q J Econ 116:933–967
Besley T, Coate S (1997) An economic model of representative democracy. Q J Econ 112:85–114
Carty RK (1988) Ireland: from predominance to competition. In: Wolinetz S (eds) Parties and party systems in liberal democracies. Routledge, London
Cox G (1994) Strategic voting equilibria under the single nontransferable vote. Am Polit Sci Rev 88:608–621
Cox G (1997) Making votes count. Cambridge University Press, Cambridge
De Sinopoli F (2000) Sophisticated voting and equilibrium refinements under plurality rule. Soc Choice Welf 17:655–672
Duverger M (1954) Political parties. Methuen, London
Engelmann FC (1988) The austrian party system: continuity and change. In: Wolinetz S (eds) Parties and party systems in liberal democracies. Routledge, London
Fey M (1997) Stability and coordination in Duverger’s law: a formal model of preelection polls and strategic voting. Am Polit Sci Rev 91:135–147
Grossman G, Helpman E (1999) Competing for endorsment. Am Econ Rev 89:501–524
Hotelling H (1929) Stability in competition. Econ J 39:41–57
Iannantuoni G (2004) A purely non-cooperative model of divided government. Soc Choice Welf 22:401–412
Leys C (1959) Models, theories and the theory of political parties. Polit Stud 7:127–146
Morelli M (2004) Party formation and policy outcomes under different electoral systems. Rev Econ Stud 71:829–853
Myerson RB, Weber RJ (1993) A Theory of voting equilibria. Am Polit Sci Rev 87:102–114
Ortuño-Ortin I (1997) A spatial model of political competition and proportional representation. Soc Choice Welf 14:427–438
Palfrey T (1989) A mathematical proof of Duverger’s law. In: Ordeshook PC (ed) Models of strategic choice in politics. University of Michigan Press, Ann Arbor, pp 69–91
Riker WH (1982) The two-party system and Duverger’s law: an essay on the history of political science. Am Polit Sci Rev 76:753–766
Sartori G (1968) Political development and political engineering. In: Montgomery JD, Hirschman AO (eds) Public policy, vol. XVII. Harbard University Press, Cambridge, pp. 261–298
Shugart MS (1995) The electoral cycle and institutional sources of divided presidential government. Am Polit Sci Rev 89:327–343
Stokey NL, Lucas RE (1989) Recursive methods in economic dynamics. Harvard University Press, Cambridge
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
De Sinopoli, F., Iannantuoni, G. A spatial voting model where proportional rule leads to two-party equilibria. Int J Game Theory 35, 267–286 (2007). https://doi.org/10.1007/s00182-006-0056-z
Revised:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00182-006-0056-z