This paper reports on a two-task principal-agent experiment in which only one task is contractible. The principal can either offer a piece-rate contract or a (voluntary) bonus to the agent. Bonus contracts strongly outperform piece rate contracts. Many principals reward high efforts on both...

Engelmann and Strobel (AER 2004) question the relevance of inequity aversion in simple dictator game experiments claiming that a combination of a preference for efficiency and a Rawlsian motive for helping the least well-off is more important than inequity aversion. We show that these results...

Most economic models are based on the self-interest hypothesis that assumes that all people are exclusively motivated by their material self-interest. In recent years experimental economists have gathered overwhelming evidence that systematically refutes the self-interest hypothesis and suggests...

We show that concerns for fairness may have dramatic consequences for the optimal provision of incentives in a moral hazard context. Incentive contracts that are optimal when there are only selfish actors become inferior when some agents are concerned about fairness. Conversely, contracts that...

This paper surveys recent experimental and field evidence on the impact of concerns for fairness, reciprocity and altruism on economic decision making. It also reviews some new theoretical attempts to model the observed behavior.

We show experimentally that fairness concerns may have a decisive impact on both the actual and the optimal choice of contracts in a moral hazard context. Explicit incentive contracts that are optimal according to self-interest theory become inferior when some agents value fairness. Conversely,...

We report on several experiments on the optimal allocation of ownership rights. The experiments confirm the property rights approach by showing that the ownership structure affects relationship-specific investments and that subjects attain the most efficient ownership allocation despite starting...

In recent decades, many firms offered more discretion to their employees, often increasing the productivity of effort but also leaving more opportunities for shirking. These “high-performance work systems” are difficult to understand in terms of standard moral hazard models. We show...