This paper develops methods for evaluating marginal policy changes. We characterize how the effects of marginal policy changes depend on the direction of the policy change, and show that marginal policy effects are fundamentally easier to identify and to estimate than conventional treatment...

This paper formulates and estimates multistage production functions for children's cognitive and noncognitive skills. Skills are determined by parental environments and investments at different stages of childhood. We estimate the elasticity of substitution between investments in one period and...

The recent literature on instrumental variables (IV) features models in which agents sort into treatment status on the basis of gains from treatment as well as on baselinepretreatment levels. Components of the gains known to the agents and acted on by them may not be known by the observing...

This paper studies the role of public policy to promote efficiency in human capital accumulation in the representative agent framework. Agents accumulate human capital by spending time in home study and in publicly provided schools. The individual faces an aggregate externality in the...

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...