We analyze a model of imperfect price competition between intermediation service providers. We insist on features that are relevant for informational intermediation via the Internet: the presence of indirect network externalities, the possibility of using the nonexclusive services of several...

This paper presents a formal theory of reciprocity. Reciprocity means that people reward kind actions and punish unkind ones. The theory takes into account that people evaluate the kindness of an action not only by its consequences but also by the intention underlying this action. The theory...

The present book adds to the broad field of investigations concerning what affects and determines human cooperation. It provides new insights into internal and external factors that influence such decisions. Rather than presenting a closed and universal examination, this book should be seen as...