Generalizing JTPA job-training effects to a national target: TRACE narrows the confidence interval by 60% and says whether baseline mismatch or follow-up loss is to blame
Generalizing randomized-trial findings to a broader target population can yield distorted estimates when the trial sample is misaligned with that population. TRACE decomposes the asymptotic variance of the efficient generalizability estimator into a baseline-mismatch channel and a censoring channel, then uses a tree search to localize underrepresented subgroups and attribute each to its mechanism. In a case study generalizing the JTPA Study to U.S. JTPA-eligible adults, restricting to reliably generalizable subgroups narrows the 95% confidence interval for the refined estimand by 60%.