This study investigates the post-high school influence of the In-School Neighborhood Youth Corps (NYC) on the earning capacity of participatns in Houston, Texas. The influence of NYC participation is investigated employing a methodology of a control group design together with data analyses using multiple regression and analysis of covariance. The analytical sample consists of 103 former participants in the NYC Program who left high school sometime between 1965 and mid-1971, and 39 controls. The NYC participants include 83 school year subjects for whom at least some of their NYC experience was obtained in part-time NYC employment during the academic year and 20 summer-only participants who held NYC jobs during the summer vacation period. The conclusions of this investigations include the following: (1) NYC participation does not improve the high school graduation rate; (2) the NYC influence on post-high school income is questionable; (3) the NYC influence on college attendance and long-run income prospects are questionable; (4) NYC participation does not stimulate post-high school vocational training; (5) NYC participation benefits blacks more than other ethnic groups; (6) the school year segment contributes more toward high school graduation than the summer-only segment; and, (7) income gains to NYC participants do not increase with the length of participation. (Author/JM)