Template-type: ReDif-Paper 1.0 Author-Name: Peeters Ronald Author-Name: Saran Rene Author-Name: Yuksel Ayse Muge Author-workplace-name: METEOR Title: Strategic Party Formation on a Circle Abstract: We study a spatial model of party formation in which the set of agendas is the unit circle. We characterize the sets of pure-strategy Nash equilibria under the plurality and proportional rules. In both rules, multiple configurations of parties are possible in Nash equilibrium. We refine our predictions using a new notion called “defection-proof” Nash equilibrium. Under the plurality rule, only those Nash equilibria in which either two or three parties exist are defection-proof, whereas multiple parties exist in any defectionproof Nash equilibrium under the proportional rule. These results are mostly consistent with the predictions of Duverger (1954).Keywords: Party Formation; Spatial Model; Plurality Rule; Proportional Rule; Nash Equilibrium; Defection-Proof Nash Equilibrium. Keywords: microeconomics ; Series: Research Memoranda Creation-Date: 2010 Number: 045 File-URL: http://digitalarchive.maastrichtuniversity.nl/fedora/objects/guid:73f6a973-1150-474a-9e65-55d3be940ed5/datastreams/ASSET1/content File-Format: application/pdf File-Size: 300700 Handle: RePEc:unm:umamet:2010045