This article attempts to determine whether wage records reported by employers to state unemployment insurance (UI) agencies provide a valid alternative to more costly retrospective sample surveys of individuals as the basis for measuring the impacts of employment and training programs for low‐income persons. We analyze UI data and survey data for a sample of low‐income adults and youths from 12 sites in the National Job Training Partnership Act (JTPA) study. Our comparison indicates that impact estimates based on UI data and survey data were usually comparable. However, average surveyreported earnings were higher than average UI‐reported earnings.

This paper assesses nonexperimental estimators using results from a six-state random assignment study of mandatory welfare-to-work programs. The assessment addresses two questions: which nonexperimental methods provide the most accurate estimates; and do the best methods work well enough to replace random assignment? Three tentative conclusions emerge. Nonexperimental bias was larger in the medium run than in the short run. In-state comparison groups produced less average bias than out-of-state comparison groups. Statistical adjustments did not consistently reduce bias, although some methods reduced the estimated bias in some circumstances and propensity-score methods provided a specification check that eliminated some large biases.