The relationship between college costs and family income is examined, along with the debt burden incurred by students while pursuing a postsecondary education. Attention is directed to an analytical model of discretionary income, the families' current income and college costs and how these have changed over the last decade, and general empirical findings and further research that would improve current modeling efforts and data availability. Discretionary income is defined as the amount of resources that remain for a family or an individual after taxes and basic living expenses are deducted. Findings include the following: the ratio of college costs (at both public and private institutions) to parental discretionary income is slightly lower than it was in 1970; between 1970 and 1979, the increase in family discretionary income far exceeded the increase in college costs; during 1979 and-1981, college costs have grown at a much faster rate than income; college graduates with borrowing and income levels around the median will have little trouble repaying education debts; students who are unemployed, working part-time, or in low-paying jobs may have relatively high burdens in the first few years of repayment. (SW)