In recent years, a large number of economic theories have evolved to explain people's pro-social behavior and the variation in their respective behavior. This paper surveys economic theories on pro-social behavior and presents evidence-mainly from the field-testing these theories. In addition,...

People often do not realize they are being influenced by an incidental emotional state. As a result, decisions based on a fleeting incidental emotion can become the basis for future decisions and hence outlive the original cause for the behavior (i.e., the emotion itself). Using a sequence of...