De Sinopoli, Francesco
Iannantuoni, Giovanna
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 coefficients equal to their share of seats, only a two-party voting equilibrium basically 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's model of divided government as well as a modified version of Besley and Coate's model of representative democracy. This result cannot be extended to a general outcome function but, however, when the policy is determined by the two leading parties, in pure strategies, only two-party equilibria can emerge. Analogous result holds for coalitions of parties.


Bibliographic reference |
De Sinopoli, Francesco ; Iannantuoni, Giovanna. A spatial voting model where proportional rule leads to two-party equilibria. CORE Discussion Papers ; 2000/37 (2000) |
Permanent URL |
http://hdl.handle.net/2078.1/4126 |