Publikationen

This paper shows that increasing the sanction on collective crime may increase its prevalence. This situation arises when individuals can commit crimes both individually and as part of a collective. Our result is based on an interdependence between detection probabilities where detection of an individual crime may result in the uncovering of the collective crime as well.

dc.title:

dc.contributor.author: Sembill, Detlef

We consider a model of evolution with mutations as in Kandori et al. (1993) [Kandori, M., Mailath, G.J., Rob, R., 1993. Learning, mutation, and long run equilibria in games. Econometrica 61, 29 56], where agents follow best-response decision rules as in Sandholm (1998) [Sandholm, W., 1998. Simple and clever decision rules for a model of evolution. Economics Letters 61, 165 170]. Contrary to those papers, our model gives rise to a birth-death process, which allows explicit computation of the long-run probabilities of equilibria for given values of the mutation rate and the population size. We use this fact to provide a direct proof of the stochastic stability of risk-dominant equilibria as the mutation rate tends to zero, and illustrate the outcomes of the dynamics for positive mutation rates.

dc.title:

We examine the optimal tax and education policy in the case of a dual income tax. Incorporating an educational sector and endogenous capital taxation, we show that the results in Nielsen and Sørensen's study are vulnerable with respect to assumptions on the elasticity of unskilled labor supply. Tax progressivity results residually, whereas educational policy guarantees an optimal tax wedge on, but not necessarily efficiency in, educational investment. The less elastic are the unobservable educational investment and skilled labor (the latter relative to unskilled labor supply), and the more educational policy cares about the skilled labor supply, the more progressive the tax system will be. Education will be subsidized on a net basis if the complementarity effect on the skilled labor supply is strong and important; however, there is also an offsetting substitutability effect of the unskilled labor supply at play.

Trust is a phenomenon that still is quite rarely investigated in agency theory. According to a common intuitive reasoning, trust should develop over time and it should evolve even in finite implicit-contract relationships. However, if the contracting parties are fully rational, theory cannot explain this. We therefore extend the standard model and develop a model of a finite relationship where the principal promises to pay a voluntary period-by-period bonus if the agent has worked according to the implicit agreement. The agent is boundedly rational and unable to foresee the principal’s future bonus decisions. The principal is, with some probability, honest and pays a promised bonus even in situations where ex-post cheating would be optimal. Based on the agent’s adaptive learning process, we show how trust evolves depending on the principal’s bonus-payment strategy. Depending on different levels of the agent’s bounded rationality, we derive the principal’s optimal pure strategy as part of a unique equilibrium. In an extension we show that the results are robust if the agent has bounded recall. The optimal strategy pattern mirrors a subset of trigger strategies which is exogenous in the standard model. Our findings imply that subjective incentives are more effective with increasing tenureof employees, or, that the optimal level of trust depends on how fast work environments change.

This paper analyzes the effect of increasing human-capital mobility — i.e. student and labor mobility—on net tax revenues when revenue-maximizing governments compete for human capital by means of income tax rates and amenities offered to students (positive expenditure) or rather tuition fees (negative expenditure). An increase in labor mobility implies neither an intensified tax competition nor an erosion of revenues. In fact, the equilibrium tax rate even increases in labor mobility. Amenities offered to students are non-monotonically related to labor mobility; overall, net revenues increase with labor mobility. An increase in student mobility, however, erodes revenues, mainly due to intensified tax competition. A concurrent cutback in expenditures mitigates this erosion but cannot fully prevent it.

We analyze whether the diversification discount is driven by the book value bias of corporate debt. Book values of debt may be a more downward biased proxy of the market value of debt for diversified firms, relative to undiversified firms, as diversification leads to lower firm risk. Thus, measures of firm value based on book values of debt undervalue diversified firms relative to focused firms. Our paper complements recent literature which uses market values to test the risk reduction hypothesis for a subsample of firms for which debt is traded. Alternatively, we employ market value of debt estimates for the whole firm universe. Consistent with the above hypothesis, we show that the use of book values of debt underestimates the value of diversified firms. There is no discount for mainly equity financed firms and lower distress risk and equity volatility for diversified firms. More concentrated ownership increases firm valuation.

We analyze the classic moral hazard problem with the additional assumption that agents are inequity averse. The presence of inequity aversion alters the structure of optimal contracts. When the concern for equity becomes more important, there is convergence towards linear sharing rules. The sufficient statistics result is violated. Depending on the environment, contracts may be either overdetermined, i.e. include non-informative performance measures, or incomplete, i.e. neglect informative performance measures. Finally, our model delivers a simple rationale for team based incentives, implying wage compression.