In this paper we analyse the portfolio selectionproblem with minimum transactionlots in the context of non-expected utility theory. We assume that the decisionmaker ranks the alternatives by using a specific DualExpectedUtility. This functionallows portfolio values less or equal a fixed...

We consider the class of (finite) spatial games. We show that the problem of determining whether there exists a Nash equilibrium in which each player has a payoff of at least k is NP-complete as a function of the number of players. Copyright Springer-Verlag Berlin/Heidelberg 2004

The theory of computation and automata has occasionally aroused some interest among political scientists. The article outlines some early applications, although the main emphasis is on the most recent ones. We concentrate on the applications to bargaining and negotiation procedures. It is argued...

Focusing on the testable implications on the equilibrium manifold, we show that the rationalizability problem is NP-complete. Subsequently, we present an integer programming (IP) approach to characterizing general equilibrium models. This approach avoids the use of the Tarski-Seidenberg...

We determine the computational complexity of various choice models that use multiple rationales to explain observed choice behavior. First, we demonstrate that the notion of rationalizability by K rationales, introduced by Kalai et al. (2002), is NP-complete for K greater than or equal to two....

In this paper we study hedonic games where each player views every other player either as a friend or as an enemy. Two simple priority criteria for comparison of coalitions are suggested, and the corresponding preference restrictions based on appreciation of friends and aversion to enemies are...

Given a finite game with common payoffs (i.e. the players have completely common interests), we show that the problem of determining whether there exists a joint strategy where each player nets at least k is NP-complete.

We consider a special case of the directed subgraph homeomorphism or topological minor problem, where the host graph has a specific regular structure. Given an acyclic directed pattern graph, we are looking for a host graph of minimal height which still allows for an embedding. This problem has...