Within a laboratory experiment we investigate a principal-agent game in which agents may, first, self-select into a group task (GT) or an individual task (IT) and, second, choose work effort. In their choices of task and effort the agents have to consider pay contracts for both tasks as offered...

The labor economics literature has shown that the "efficient bargaining" model, in which wage and employment are negotiated simultaneously, is less frequently used on unionized markets than the less efficient "right-to-manage" model, in which wage is determined via bargaining and employment...

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...