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...

A substantial number of people exhibit social preferences, which means they are not solely motivated by material self-interest but also care positively or negatively for the material payoffs of relevant reference agents. We show empirically that economists fail to understand fundamental economic...

This paper reports the results of a series of competitive labour market experiments in which subjects have the possibility to reciprocate favours. In the high stake condition subjects earned between two and three times their monthly income during the experiment. In the normal stake condition the...

This paper examines how the presence of a non-negligible fraction of reciprocally fair actors changes the provision of incentives through contracts. We provide experimental evidence that principals have a strong preference for less complete contracts although the standard self-interest model...

During the last two decades economists have made much progress in understanding incentives, contracts and organisations. Yet, they constrained their attention to a very narrow and empirically questionable view of human motivation. The purpose of this paper is to show that this narrow view of...

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...

This paper analyzes awards as a means of motivation prevalent in the scientific community, but so far neglected in the economic literature on incentives, and discusses their relationship to monetary compensation. Awards are better suited than performance pay to reward scientific tasks, which are...