{"kind":"user","text":"Dehejia and Wahba (1999), 'Causal Effects in Nonexperimental Studies', Table 2, Panel B (the RE74 subsample: the men of LaLonde's NSW sample for whom 1974 earnings are available), column (1), the row that uses the NSW experimental control group: estimate the unadjusted effect of the training program on 1978 earnings by regressing 1978 earnings on the treatment indicator alone, by ordinary least squares. Report the coefficient on the treatment indicator."}