Rising college prices, stagnating incomes, and diminished asset values have led to the widespread perception that college is "unaffordable" for more and more people. The role of student aid in reducing the prices many students pay is too complex to be widely understood, and in spite of increasing enrollment rates, most people do not question the idea that college is unaffordable. The goal of this brief is to make progress in understanding what it really means for college to be "affordable" or "unaffordable." The idea that college is unaffordable simply because it is "too expensive" is not very constructive, and the common practice of comparing published tuition prices--or the combination of tuition and living expenses--with family incomes is misleading. Understanding the complex factors affecting the actual price of college, perceptions of that price, and the very real (and not so real) struggles facing today's students is vital to efforts to increase educational opportunity. In an effort to develop the foundation for more constructive policy discussions on the financial barriers to postsecondary education, this brief discusses a variety of ways to approach the concept of affordability. The first step is to review work in two other policy areas--housing and health care--in which affordability issues receive considerable attention. Although the subjectivity of the term "affordability" cannot be avoided, housing and health care analysts have made some progress in developing benchmarks. The brief then discusses two important facets of the debate about affordability that should be clear in the minds of policymakers. First, the costs and benefits of college are widely misunderstood. In particular, the concept of "net price"--the price students pay after receiving financial aid that does not have to be repaid--is difficult to communicate. Second, the uncertain return on higher education makes the investment risky and therefore less attractive for many people. (Contains 3 tables and 14 footnotes.)