In Harsanyi's impartial observer theorem, an impartial observer determines a social ordering of the lotteries on the set of social alternatives based on a sympathetic but impartial concern for all individuals in society. This ordering is derived from a more primitive ordering on the set of all...

Tax competition between two governments who choose nonlinear income tax schedules to maximize the average utility of its residents when skills are unobservable and labor is perfectly mobile is examined. We show that there are no Nash equilibria in which there is a skill type that pays positive...