There is an extensive literature claiming that it is often difficult to make use of arbitrage opportunities in financial markets. This paper provides a new reason why existing arbitrage opportunities might not be seized. We consider a world with short-lived securities, no short-selling...

When the asset market is incomplete, competitive equilibria are constrained suboptimal, which provides a scope for pareto improving interventions. Price regulation can be such a pareto improving policy, even when the welfare effects of rationing are taken into account. An appealing aspect of...

In this paper, the standard two-period general equilibrium model with incomplete financial markets is considered. First, existence of equilibrium is proved using a stationary point argument on the set of no-arbitrage prices. Prices are normalized with respect to the market portfolio. The proof...

Many economic and social situations can be represented by a digraph. Both axiomatic and iterative methods to determine the strength or power of all the nodes in a digraph have been proposed in the literature. We propose a new method, where the power of a node is determined by both the number of...

In a standard general equilibrium model it is assumed that there are no price restrictions and that prices adjust infinitely fast to their equilibrium values. Price rigidities may cause that a competitive equilibrium cannot be attained, and rationing on net demands or supplies is needed to clear...

In this paper we generalize the concept of a non-transferable utility game by introducing the concept of a socially structured game. A socially structured game is given by a set of players, a possibly empty collection of internal organizations on any subset of players, for any internal...

This discussion paper led to a publication in 'Social Choice and Welfare', 2005, 24, 439-454.<P> Many economic and social situations can be represented by a digraph. Both axiomatic and iterativemethods to determine the strength or power of all the nodes in a digraph have been proposed inthe...</p>

This discussion paper resulted in a publication in 'Games and Economic Behavior', 2007, 59, 85-104. <P> We consider cooperative games with transferable utility (TU-games), in which we allow for a social structure on the set of players. The social structure is utilized to refine the core of the...</p>

In a standard general equilibrium model it is assumed that there are no price restictionsand that prices adjust infinitely fast to their equilibrium values. In this paper the set ofadmissible prices is allowed to be an arbitrary convex set. For such an arbitrary set it cannotbe guaranteed that...