This paper discusses some problems in determining the optimal use of road safety measures. The first of these problems is how best to define the baseline option, i.e. what will happen if no new safety measures are introduced. The second problem concerns choice of a method for selection of...

The economic and environmental benefits of gum arabic production in the Sudano-Sahelian zone appear attractive. However, the farm-level economics of gum arabic production is complex, and much more needs to be understood about the economic-environmental interactions determining farmers' gum...

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...