Like Feinberg and Sherman (1985) and Phillips and Mason (1992), we test experimentally whether conglomerate firms, i.e. firms competing on multiple, structurally unrelated markets, effectively limit competition through forbearance. Unlike these authors, our more general analysis assumes differentiated rather than homogeneous products and distinguishes strategic substitutes as well as complements to test their forbearance hypothesis. We vary the duration of the interaction to disentangle effects of forbearance and repetition. Surprisingly, rather than limiting competition, conglomerate firms foster it. In line with our expectations, we find more cooperation with strategic complements than with strategic substitutes and also more cooperation with long term than with short term interaction.

Even if contract enforcers are as opportunistic as ordinary traders, a system of adjudication can increase the degree to which contractual obligations on large anonymous markets are fulfilled. Only if arbitrators receive a fixed income, occasional mistakes will not favour the untrustworthy. It can be shown that the presence of the courts may further the prospects of the trustworthy in a large class of situations. But under non-optimal court policies and unfavorable parameter constellations introducing courts may crowd out trustworthiness.Criminal Law and Conflicts of Honour

Take-it or leave-it offers are probably as old as mankind. Our objective here is, first, to provide a, probably subjectively-colored, recollection of the initial ultimatum game experiment, its motivation and the immediate responses. Second, we discuss important extensions of the standard ultimatum bargaining game in a unified framework, and, third, we offer a survey of the experimental ultimatum bargaining literature containing papers published since the turn of the century. The paper argues that the ultimatum game is an extremely versatile tool for research in bargaining and on social preferences. Finally, we provide examples for open research questions and directions for future studies.