Haavelmo's seminal 1943 paper is the first rigorous treatment of causality. In it, he distinguished the definition of causal parameters from their identification. He showed that causal parameters are de fined using hypothetical models that assign variation to some of the inputs determining...

In this paper, we suggest a novel approach to program evaluation that allows identification of the causal effect of a training program on the likelihood of being invited to a job interview under weak assumptions. The idea is to measure the program-effects by pre- and posttreatment data that are...

We show experimentally that a principal?s distrust in the voluntary performance of an agent has a negative impact on the agent?s motivation to perform well. Before the agent chooses his performance, the principal in our experiment decides whether he wants to restrict the agents? choice set by...

Field evidence suggests that people belonging to the same group often behave similarly, i.e., behaviour exhibits social interaction effects. We conduct an experiment that avoids the identification problem present in the field. Our novel design feature is that each subject simultaneously is a...

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...

We present an economic experiment on network formation, in which subjects can decide to form links to one another. Direct links are costly but being connected is valuable. The gametheoretic basis for our experiment is the model of Bala and Goyal (2000). They distinguish between two scenarios...

This paper investigates the driving forces behind informal sanctions in cooperation games and the extent to which theories of fairness and reciprocity capture these forces. We find that cooperators' punishment is almost exclusively targeted towards the defectors but the latter also impose a...

This paper investigates whether risk preferences explain how individuals are sorted into occupations with different earnings variability. We exploit data from the German Socio-Economic Panel, which contains a subjective assessment of willingness to take risks whose behavioral relevance has been...

When unemployment prevails, relations with a particular firm are valuable for workers. As a consequence, a worker may adhere to an implicit agreement to provide high effort, even when performance is not third-party enforceable. But can implicit agreements - or relational contracts - also...

This paper examines the correlated random coefficient model. It extends the analysis of Swamy (1971, 1974), who pioneered the uncorrelated random coefficient model in economics. We develop the properties of the correlated random coefficient model and derive a new representation of the variance...