We demonstrate how altruism can flourish in a population of nonaltruists. We assume that each individual plays a one-shot prisoner's dilemma game with his or her sibling and that the probability than an individual survives to reproduce is proportional to his or her payoff in this game. We model...

This paper examines the optimal direction of marginal income tax reform in the context of New Zealand, which recently reduced its top marginal income tax rate to one of the lowest in the OECD. A behavioural microsimulation model is used, in which social welfare functions are defined in terms of...