The study assessed the use of vouchers for funding manpower training, using the GI bill as a test case. Focus was on vocational training, although on-the-job training (OJT), correspondence, and college training were also examined. The value of training was estimated by the extent to which it leads to increased earnings. Longitudinal earnings histories of veterans who used each type of training were compared to those of a control group of nonusers with similar personal characteristics and initial earning capacity. The gain due to training was estimated as the difference between the earnings of trainees and the earnings of the control group. The study showed that vocational trainees funded by the GI bill increased their earnings by about 10%, about twice as great an increase as had been estimated elsewhere for nonvoucher government programs. The training appeared to be particularly valuable for blacks and for those with relatively little prior education. Analysis of the use of benefits by Vietnam-era veterans showed that blacks participate in training at a higher rate than similar whites. (Author/HD)