Both in the field and in the lab, participants frequently cooperate, despite the fact that the situation can be modelled as a simultaneous, symmetric prisoner’s dilemma. This experiment manipulates the payoff in case both players defect, and explains the degree of cooperation by a combination...

The novel part of this paper is a model of the principle of proportionality, as the cornerstone of the doctrine of fundamental rights. German law, and with some modifications also the law of the European Community and the European Convention on Human Rights, do not categorically outlaw...

From the perspective of competitors, competition may be modeled as a prisoner’s dilemma. Setting the monopoly price is cooperation, undercutting is defection. Jointly, competitors are better off if both are faithful to a cartel. Individually, profit is highest if only the competitor(s) is...

The European Commission is working on a revision of its Guidelines on Research and Development Agreements. On this occasion, this note surveys the existing experimental evidence. Experiments add a number of additional arguments to the normative assessment. R&D agreements have a much smaller...

Broken Windows: the metaphor has changed New York and Los Angeles. Yet it is far from un-disputed whether the broken windows policy was causal for reducing crime. In a series of lab experiments we put two components of the theory to the test. We show that first impressions and early punishment...

Does probation pay a double dividend? Society saves the cost of incarceration, and convicts preserve their liberty. But does probation also reduce the risk of recidivism? In a meta-study we show that the field evidence is inconclusive. Moreover it struggles with an identification problem: those...

We report on our test of the Large Language Model (LLM) ChatGPT (GPT) as a tool for generating evidence of the ordinary meaning of statutory terms, We explain why the most useful evidence for interpretation involves a distribution of replies rather than only what GPT regards as the single "best"...