Increasingly students must help shoulder the costs of college. Concerned with equity and diversity in admissions, colleges and universities are also doing more of the heavy lifting themselves, and rightly so.

The public focuses, understandably, on rising college tuition rates, but the actual cost of higher education per student at Cornell -- and at many other universities -- is actually about double the price of tuition. In effect, tuition is subsidized for all students, whether they qualify for aid or not. The remainder of the education funding comes from university endowments, gifts and government support.

Cornell and many other colleges provide aid for students who demonstrate need. For institutions with need-blind admissions -- accepting students without regard to their ability to pay educational costs -- that subsidy is substantial, but gives all students the advantages of studying and living with the most qualified and diverse community possible.

Recently, Harvard, the University of Pennsylvania and a few others have made laudable efforts to increase the economic diversity of their student bodies by using institutional resources to substitute grants for loans. Unfortunately, very few institutions can match their offers.

Cornell is one of the wealthiest U.S. universities, and we have increased grants and reduced loans for low-income students. We cannot, however, completely substitute grants for loans and also continue to broaden access, meet the financial need of all deserving students, compete with peers and preserve academic excellence in a time of rapidly rising costs.

Although Cornell has the 18th-largest college endowment nationwide, it has the lowest per-student endowment in the Ivy League and a relatively high proportion of students receiving aid. Meanwhile, educational costs for colleges, across the board, are rising faster than revenue. Indeed, inflation rates for such college budget items as faculty salaries, library collections and equipment exceed Consumer Price Index inflation rate.

Also,higher education is labor intensive -- about 60 percent of Cornell's budget, for instance, goes to employee-related costs. Other factors that drive up costs include technology and infrastructure to support faculty and student research; compliance with government regulations; expectations for enhanced services and amenities in housing, dining, fitness facilities and technology; mental health services; and competition for students. As New York's land-grant institution, Cornell also must support programs to translate the university's research into usable forms for the public.

Even though we at Cornell and other universities continually review our efforts to contain costs, and are as innovative in our approach to cost as we are in our commitment to research and teaching, costs keep climbing. Yet government and other outside support does not. (Local and state spending per student on higher education was at a 25-year low in 2004-05.)

Also, Cornell's need-blind admissions policy characterizes fewer and fewer colleges and universities. But Cornell's legacy that higher education should be open to all is expensive. In the 2006-07 academic year, 45 percent of Cornell undergraduates -- some 6,181 students -- demonstrated financial need and 41 percent qualified for grant aid (which does not have to be repaid).

To fulfill our legacy, we work to increase the number of underrepresented minority students, from fewer than 25 in 1964-65 to almost 1,500 today (about 11 percent of the overall undergraduate student body), by using new ways of communicating with students from different backgrounds, and special preparation and support programs for prospects and applicants whose families have not previously gone to college.

We are also providing enhanced financial-aid packages with more grant aid and less self-help for low-income students. The percentage of undergraduates who receive low-income Pell Grant awards at Cornell is relatively high, compared with our peer institutions, but even so, Cornell and most of its peers are below the national average. Clearly there is room for progress at all selective institutions.

Cornell recently made the treatment of family assets (such as a family residence) more favorable than before to middle-income families, understanding that these families often borrow substantially for higher education. Cornell also has increased its unrestricted grant funds (largely from tuition revenues) 177 percent in inflation-adjusted terms and its restricted grant funds (from operating gifts and endowment payout) by 181 percent since 1987-88. During the same period, government grants declined 10 percent in inflation-adjusted terms. To increase unrestricted grant aid is tantamount to raising tuition (as the major source of such aid), while restricted grant aid can grow only if additional gifts are received or endowment payout is increased.

In the future, higher education will continue to redefine its approach to student aid. And Cornell will continue to seek new ways to ensure the ability of Ezra Cornell's "any student" to gain access to our institution. The ideal of being open to all is a core institutional value at Cornell as the only right and fair course. But we cannot, at least at present, afford to emulate those few institutions that promise to meet all financial need with grant aid. Nor can most institutions of higher education. To meet the challenges all of us face will take cooperation among all the players involved in supporting higher education.

Carolyn (Biddy) Martin is the provost of Cornell. An expanded version of this article originally appeared in the April 27, 2007, Chronicle of Higher Education.