We propose an approach to the valuation of payoffs in general semimartingale models of financial markets where prices are nonnegative. Each asset price can hit 0; we only exclude that this ever happens simultaneously for all assets. We start from two simple, economically motivated axioms, namely...

In a numéraire-independent framework, we study a financial market with N assets which are all treated in a symmetric way. We define the fundamental value *S of an asset S as its superreplication price and say that the market has a strong bubble if *S and S deviate from each other. None of these...

The evolutionary selection of outcomes (modelled using the replicator dynamics) in games with costless communication depends crucially on the structural assumptions made on the underlying population. (1) In conflicts between two interacting populations, common interest implies that the set of...

In standard auctions with symmetric, independent private value bidders resale creates a role for a speculator - a bidder who is commonly known to have no use value for the good on sale. For second-price and English auctions the efficient value-bidding equilibrium coexists with a continuum of...

Non-parametric data envelopment analysis (DEA) estimators based on linear programming methods have been widely applied in analyses of productive efficiency. The distributions of these estimators remain unknown except in the simple case of one input and one output, and previous bootstrap methods...

Numerous laboratory experiments show that workers reciprocate to high wages with high effort, when there is perfect information on the surplus created. Recent field experiments, however, suggest that trust and reciprocity may be lower or absent when the information is incomplete. We report a...