This thesis aims to highlight the impact and the interaction of trust and other-regarding preferences in organizations. It is investigated whether people with social preferences like reciprocity, altruism or inequity aversion might be motivated not only by monetary incentives like bonuses or performance-based compensation schemes, but also by trust and fairness concerns. Each chapter analyzes a specific aspect of an experimental labor market and investigates the influence of social preferences on the way to motivate people in organizations. The first part of the thesis analyzes if trustful people who are treated trustworthily themselves might react reciprocally and voluntarily perform better as if they were controlled. This phenomenon is investigated in three different experimental studies for individual as well as for group behavioral patterns. It is shown that provided some specific environmental aspects an individual�s motivation indeed can be increased by a trustful handling. However, this effect only holds in an individual context and is not longer seen in a team context. The second part of the thesis analyzes the impact of inequity aversion when workers are paid unequal wages. The results of two experimental studies show that employees react significantly to unequal wages. However, neither pure distributional nor pure intentional concerns can explain the employees� reaction to unequal wages. Their behavior seems to be strongly affected by both aspects
