The Survey of Income and Program Participation (SIPP) was used to compare estimates of the benefits of education among different levels of education and thereby identify the returns to education and training in the subbaccalaureate labor market. The study data consisted of information on the educational attainment and income of 14,537 (7,981 males, 6,556 females), 10,384 (5,452 males; 4,952 females); and 20,539 (10,600 males; 9,939 females) SIPP respondents (aged 25-64 years) for calendar years 1984, 1987, and 1990, respectively. Estimating equations describing respondents' earnings as a function of education and other conventional independent variables were constructed, and the results were analyzed. Both certificates and associate degrees were found to increase the earnings of those who received them, albeit not by as much as a baccalaureate degree does. Some kinds of postsecondary education provided no economic advantage at all, and completion of a certificate proved more beneficial than completion of years of college without a credential. As is the case for baccalaureate degrees, the benefits of subbaccalaureate credentials varied substantially by field of study and the effects of having a job related to one's field of study proved substantial. (Sixteen tables are included. Information about the samples and selected independent variables and a field of study-occupation matching algorithm are appended. Contains 44 references. (MN)