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...

Individual behavioral differences in humans have been linked to measurable differences in their mental activities, including differences in their implicit motives. In humans, individual differences in the strength of motives such as power, achievement and affiliation have been shown to have a...

In this paper, we compared the models for selecting the optimal portfolio based on different risk measures to identify the periods in which some of the risk measures dominated over others. For decades, the best known return-risk model has been Markowitz's mean-variance model. Based on the...

This chapter presents the theory of international environmental agreements (IEAs). It explains what treaties do (or should do); when and why they succeed or fail; and whether they can be designed better. It focuses on the main questions that the literature on this topic has tried to answer,...