It is found that students enrolled in postsecondary vocational education programs generally display substantially lower scores than other postsecondary students on tests of literacy skills. However, these lower literacy skills are partially explained by the differences in the characteristics of the students who select to enter a vocational education program relative to other postsecondary institutions. Students enrolled in postsecondary vocational education have on average parents with lower socioeconomic background than students registered in other postsecondary institutions. Furthermore, students in bachelor's programs on average stay longer in school than students in vocational education. A multivariate analysis of the determinants of literacy skills suggests that adjusting for socioeconomic status as well as other background characteristics of individuals does reduce substantially the observed gap in literacy skills between students in vocational education and students in other tracks. However, there remains a statistically significant shortfall, even after holding constant an array of individual background variables. The characteristics of the students enrolled in vocational education programs do not, therefore, totally explain their comparatively poorer performance in literacy skills tests. The remaining shortfall may be associated with the characteristics of the programs themselves such as their content and/or the quality of their curriculum. However, it must be strongly emphasized that the cross-sectional evidence presented here is only suggestive and that to provide a reliable answer to this question requires the use of longitudinal data, comparing literacy skills before and after students enter vocational education and other postsecondary programs.
The study's statistical analysis of the link between participation in secondary and postsecondary vocational education programs and labor market outcomes shows, firstly, that, holding other things constant, persons who complete a vocational education track in high school do not have significantly different earnings later in life when compared to those individuals who complete their secondary education in schools without tracking. In addition, persons who have participated in formal postsecondary vocational/technical education institutions tend to have earnings significantly higher than those of individuals without any postsecondary education. At the same time, the Mincerian rate of return to postsecondary vocational/technical education is lower than for associate and bachelor's degrees. This result may be explained, however, by the differences in the length of the educational process in vocational/technical education institutions, which is much shorter than the longer two-year associate degrees and four-year college degrees. Furthermore, the lower estimated rate of return to vocational/technical training may be explained by self-selection effects, due to the fact that persons who select to enroll in postsecondary vocational education also tend to come from families with lower socioeconomic backgrounds. The comparatively low measured rate of return to vocational/technical education relative to associate and bachelor's degrees may, therefore, be explained by differences in unmeasured characteristics of persons in various postsecondary education programs.
The study concludes with an analysis of the potential impact of linking vocational education programs with academic study programs leading to high school. It is found that, among students who do not pursue postsecondary education, those receiving a GED have similar literacy skills to those of students who have received a high school diploma. Furthermore, among those persons who do not pursue postsecondary education, the Mincerian rate of return to a GED does not appear to be lower than that of a high school diploma. It must be stressed, though, that the strong positive linkage between a GED and both literacy and earnings, when compared to a high school diploma, may be due to a greater selectivity of the GED population when compared to high school graduates. The study compares the literacy and earnings of persons who do not pursue any postsecondary education, that is, whose highest educational attainment is a high school diploma or equivalent. Since a larger proportion of high school graduates pursue postsecondary education when compared to GED holders, and these are usually the persons with greater academic achievement, the sample of persons whose highest educational attainment is just high school constitutes a negatively selected group. Persons who pursue a GED, on the other hand, are usually the most motivated, and have the highest academic achievement, among high school dropouts (they also tend to have a greater number of years of high school compared to dropouts who do not pursue a GED). The positive selectivity of GED holders and the negative selectivity of persons who have a high school diploma as their highest educational level may account for the apparent equivalence of the two groups in literacy and earnings, as determined in this study. If this is the case, then, it is not the GED as such that provides the literacy and earnings gains documented in this paper, but rather the dynamism and selectivity of GED holders.