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 share of votes, essentially only a two-party equilibrium exists. The two...

We prove two results on the generic determinacy of Nash equilibrium in voting games. The first one is for negative plurality games. The second one is for approval games under the condition that the number of candidates is equal to three. These results are combined with the analogous one obtained...

Constitutional structures shape politicians' behaviour and hence policy outcomes through the di fferent incentive schemes at work. In this paper we analyse these mechanisms in parliamentary and presidential systems. Such a comparison is carried over by analysing how the two systems are able to...

In this paper we propose a model in which there are ideological and strategic voters who vote under poportional rule. We prove that the behavior of ideological voters matters, in that it a¤ects the outcome. We also show how a subset of strategic voters changes his voting be- havior to balance...

We prove that for generic plurality games with positive cost of voting, the number of Nash equilibria is finite. Furthermore all the equilibria are regular, hence stable sets as singletons.

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...

Purely non-cooperative principles, as iterated dominance and backward induction, explain divided government.

Using the spatial theory of voting, this paper describes an institutional structure where there are two branches of the government: the executive, elected by plurality rule, and the legislative elected by proportional rule. The resulting policy outcome is described through a compromise between...

We present a model where a society elects a parliament by voting for candidates belonging to two parties. The electoral rule determines the seats distribution between the two parties. We analyze two electoral rules, multidistrict majority and single-district proportional. In this framework, the...