Tax credit bills of various sorts were passed by the U.S. Senate in 1967, 1969, 1971, and 1976, with recent votes favoring the idea by about a two-to-one margin. Longstanding opposition in the Ways and Means Committee has heretofore prevented a postsecondary education expense tax allowance bill from reaching the floor of the House of Representatives. In the spring of 1977, however, hearings on tax allowance bills were held by a House budqet committee task force, which indicated to some that the legislative climate for passage of a credit or deduction had improved. At the same time, important questions remain to be answered: How much would a tax allowance cost the Treasury in forgone revenues? Who would benefit? What would be the effect of such a measure on different types of collegiate and noncollegiate institutions. In this analysis the justifications for the allowance are reviewed, the major provisions of the currently considered bill are set out, and a model for analyzing the bill is prescribed. Presented are the findings when available data are run through the model, and the implications of the law are discussed for both static and changing enrollment patterns. (MSE)