Nearly all discussions about the appropriate consumption discount rate for climate-change policy evaluation assume that a single discount rate concept applies. We argue that two distinct concepts and associated rates apply. We distinguish a social-welfare-equivalent discount rate appropriate for...

The growing application of cost-effectiveness (CE) analysis and controversies about its methods has led to a need to explore its welfare economic foundations. Examination of its welfare theoretic foundations can provide a rationale for selecting specific standards for the application of CE...

The view that intergenerational distributive justice and efficiency should be treated separately is familiar, yet controversial. This article elaborates the often-implicit justifications for separate treatment and provides a more express statement of how and when such treatment is appropriate....

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...

Evaluations of workfare programs in poor rural economies have typically ignored two features that policy makers stress: involuntary unemployment and the expected welfare losses from work requirements. The paper generalizes past evaluation theory and methods to incorporate both features, and...

We examine the investment decision problem of a group whose members have heterogeneous time preferences. In particular, they have different discount factors for utility, possibly not exponential. We characterize the properties of efficient allocations of resources and of shadow prices that would...

In order to lengthen prison terms, many U.S. states have limited parole boards' traditional authority to grant early releases. I develop a framework in which the welfare effects of this reform depend on (1) the elasticity of future recidivism with respect to time in prison, (2) the accuracy of...

In Fairness versus Welfare, we advance the thesis that social policies should be assessed based entirely on their effects on individuals' well-being. This thesis implies that no independent weight should be accorded to notions of fairness (other than many purely distributive notions). We support...

Understanding whether criminal behavior is %u201Ccontagious%u201D is important for law enforcement and for policies that affect how people are sorted across social settings. We test the hypothesis that criminal behavior is contagious by using data from the Moving to Opportunity (MTO) randomized...

In this essay we review what is known about Head Start and argue that the program is likely to generate benefits to participants and society as a whole that are large enough to justify the program's costs. Our conclusions differ importantly from those offered in some previous reviews because we...