An auction is externality-robust if unilateral deviations from equilibrium leave the other bidders’ payoffs unaffected. The equilibrium and its outcome will then persist if certain types of externalities arise between bidders. One example are externalities due to spiteful preferences, which...

A principal uses security bid auctions to award an incentive contract to one among several agents in the presence of hidden action and hidden information. Securities range from cash to equity and call options. “Steeper” securities are better surplus extractors that narrow the gap between the...

The literature on public goods has shown that efficient outcomes are impossible if participation constraints have to be respected. This paper addresses the question whether they should be imposed. It asks under what conditions efficiency considerations justify that individuals are forced to pay...

The Mirrleesian model of income taxation restricts attention to simple allocation mechanism with no strategic interdependence, i.e., the optimal labor supply of any one individual does not depend on the labor supply of others. It has been argued by Piketty (1993) that this restriction is...