If you need a little extra motivation to set aside college savings each month, consider this: With a volatile stock market taking a bite out of college endowments, financial aid budgets are shrinking and assistance will be harder to come by. Worse, many colleges are choosing not to admit students who need aid.

Today, relatively few schools have the financial wherewithal to disregard a student’s ability to pay when making admissions decisions. According to Donald E. Heller, an associate professor and senior research associate at Pennsylvania State University, only about three dozen colleges and universities now commit themselves to meet every admitted student’s need. “So it’s safe to conclude that all other institutions, to one extent or another, take financial need into account when deciding which students to admit,” says Heller.

Will your children be affected? It depends on the strength of their credentials, Heller says. Most top candidates will be accepted regardless of need, and may even be awarded merit scholarships. But other students may be judged in part on the basis of how much they will cost the school. “When admissions staffs get down to those last pools of applicants, very often they will not admit students who need financial aid if they know the school can’t meet that need,” says Heller. “At that point, candidates who can pay their own way have an advantage.”

That’s not the way things generally worked during the 1970s and early 1980s, when most colleges at least aspired to need-blind admissions policies. By the mid-’80s, however, most admissions offices had adopted a more pragmatic business model often referred to as enrollment management. The bottom line for the admissions staff was simple: Fill the class but don’t exceed the financial aid budget.

Today, enrollment management is firmly entrenched at most schools. Moreover, with economics affecting alumni giving and pressure being put on endowment earnings, a student’s financial situation plays an increasingly critical role in the admissions process. As a result, strategies for maximizing a student’s apparent need by putting assets in parents’ names and taking advantage of aid formulas that require students to spend a larger proportion of their own savings could have undesirable consequences. And not saving for college at all, while counting on financial aid to bear the brunt of school costs, could prevent your children from getting into the colleges of their choice.

The safest approach to college funding is to plan to pay as much as possible yourself. Positioning your assets to qualify for financial aid or counting on the availability of loans could backfire with the admissions office and your kids.