Burkhard Hehenkamp

Equilibrium Selection in the Two-Population KMR Model

This paper shows that, for the class of individualistic adjustment dynamics, unique equilibrium selection is possible in the two-population model of evolution by Kandori, Mailath and Rob (1993). We establish that, for generic 2×2 co-ordination games, the evolutionary process always selects the mutation-dominant equilibrium. Though the concepts of mutation dominance and risk dominance yield different equilibrium predictions, we show that mutation dominance represents a natural extension of risk dominance that additionally captures the risk arising from the evolutionary environment.

The Inefficiency of Market Transparency – A Model with Endogenous Entry

Including the entry decision in a Bertrand model with imperfectly informed consumers, we introduce a trade-off at the level of social welfare. On the one hand, market transparency is beneficial when the number of firms is exogenously given. On the other, a higher degree of market transparency implies lower profits and hence makes it less attractive to enter the market in the first place. It turns out that the second effect dominates: too much market transparency has a detrimental effect on consumer surplus and on social welfare.

When Should the Talented Receive Weaker Incentives? Peer Pressure in Teams

We study optimal incentive contracts offered to teams where team members feel a social pressure to exert similar effort levels. The team consists of two groups of agents differing in their productivity. We characterize first best and the equilibrium under agency. Regarding economic incentives, the principal has to adjust the incentives away from the first-best incentives that would arise in the absence of peer pressure. In equilibrium less productive agents exert less effort and all agents experience peer pressure.

Too much of a good thing? Welfare consequences of market transparency

This paper studies welfare consequences of consumer-side market transparency with endogenous entry of firms. Different from most studies, we consider the unique symmetric entry equilibrium, which is in mixed strategies. We identify two effects of market transparency on welfare: a competition effect and a novel market-structure effect. We show, surprisingly, that for almost all demand functions the negative market-structure effect eventually dominates the positive competition effect as the market becomes increasingly transparent. Consumer-side market transparency can therefore be socially excessive even without collusion. The only exception among commonly used demand functions is the set of constant demand functions.

Paying for Performance in Hospitals

A frequent form of pay-for-performance programs increase reimbursement for all services by a certain percentage of the baseline price. We examine how such a “bonus-for-quality” reimbursement scheme affects the wage contract given to physicians by the hospital management. To this end, we determine the bonus inducing hospitals to incentivize their physicians to meet the quality standard. Additionally, we show that the health care payer has to complement the bonus with a (sometimes negative) block grant. We conclude the paper relating the role of the block grant to recent experiences in the American health care market.