It is suggested that individual behavior under ambiguity, or knightian uncertainty, may represent an alternative explanation for contractual incompleteness with respect to the traditional approach in terms of transactions costs. This paper aims at showing that the introduction of ambiguity in...

Cooperation among genetically unrelated agents occurs in many situations where economic theory would not expect it. A too narrow conception of self-interest is widely considered the culprit. In particular, relying on experimental evidence in plenty, we consider strong reciprocity rules of...