I study attitudes towards risk taking in cases where a person relates to others positively, namely altruistically. This study is needed because it is unclear how altruism influences the inclination of an altruistic person to take risks. Will this person's risk-taking behavior differ if the...

Consider a population of farmers who live around a lake. Each farmer engages in trade with his m adjacent neighbors, where m is termed the "span of interaction". Trade is governed by a prisoner's dilemma "rule of engagement". A farmer's payoff is the sum of the payoffs from the m prisoner's...

This paper asks whether population growth is conducive to the sustainability of cooperation. A simple model is developed in which farmers who live around a circular lake engage in trade with their adjacent neighbors. The payoffs from this activity are governed by a prisoner's dilemma "rule of...

We study the joint role of altruism and impatience, and the impact of evolution in the formation of long-term time preferences and in the determination of optimal consumption and optimal bequests. We show how the consumption paths of dynasties relate to altruism and to impatience and we reason...

We calculate the equilibrium fraction of cooperators in a population in which payoffs accrue from playing a single-shot prisoner's dilemma game. Individuals who are hardwired as cooperators or defectors are randomly matched into pairs, and cooperators are able to perfectly find out the type of a...

We offer a game-theoretic proof of Hamilton's rule for the spread of altruism. For a simple case of siblings, we show that the rule can be derived as the outcome of a one-shot prisoner's dilemma game between siblings. -- evolution of altruism ; Hamilton's rule ; one-shot prisoner's dilemma game