A recent literature has developed that combines two prominent empirical approaches to ex ante policy evaluation: randomized controlled trials (RCT) and structural estimation. The RCT provides a "gold-standard'' estimate of a particular treatment, but only of that treatment. Structural estimation...

Section I introduces the material. In section II a model is developed which explores the impact of input-quality uncertainty on factor demand from which is derived a rationale for the use of devices which segment the population into classes differing in their "skill" distribution parameters. The...