Efficiency under contractual incompleteness often requires voluntary cooperation in situations where self-regarding incentives for contractual compliance are present as well. Here we provide a comprehensive experimental analysis based on the gift-exchange game of how explicit and implicit...

Explicit and implicit incentives and opportunities for mutually beneficial voluntary cooperation co-exist in many contractual relationships. In a series of eight laboratory gift-exchange experiments, we show that incentive contracts can lead to crowding out of voluntary cooperation even after...