"Optimal policy rules--including those regarding income taxation, commodity taxation, public goods, and externalities--are typically derived in models with homogeneous preferences. This article reconsiders many central results for the case in which preferences for commodities, public goods, and...

Recent research on the economics of human development deepens understanding of the origins of inequality and excellence. It draws on and contributes to personality psychology and the psychology of human development. Inequalities in family environments and investments in children are substantial....