Planners often face the especially difficult and important task of assigning programs or treatments to optimize outcomes. Using the recent welfare-to-work reforms as an illustration, this paper considers the normative problem of how administrators might use data from randomized experiments to...

The basic idea of program evaluation is both simple and appealing. Program outcomes are measured and compared to some minimum performance standard or threshold. In practice, however, evaluation is quite difficult. Two fundamental problems of outcome measurement must be addressed. The first,...

Econometric analyses of treatment response commonly use instrumental variable (IV) assumptions to identify treatment effects. Yet the credibility of IV assumptions is often a matter of considerable disagreement. There is therefore good reason to consider weaker but more credible assumptions. To...

Under the new welfare system, states must design and institute programs that both provide assistance and encourage work, two objectives that have thus far appeared incompatible. Will states meet these new requirements? For many innovative programs, the randomized welfare-to-work experiments...

We investigate what can be learned about the prevalence of work disability using self-reported assessments of work capacity. Although health status is widely recognized as a crucial determinant of labor supply behavior and participation in public transfer programs, there is a long-standing...

We analyze the incidence of ad valorem and unit excise taxes in an oligopolistic industry with differentiated products and price-setting (Bertrand) firms. Both taxes may be passed on to consumers by more than 100 percent, and an increase in the tax rate can increase short run firm profits (and...

This paper considers the relative efficiency of ad valorem and unit taxes in imperfectly competitive markets. We provide a simple proof that ad valorem taxes are welfare-superior to unit taxes in the short run when production costs are identical across firms. The proof covers differentiated...