As a nation, we've racked up more than $1 trillion in student loans, and education experts are saying that these loans come at a time when a growing number of young people are mounting heaves of debt but no degree to show for it.

Nearly 30 percent of college students who took out loans dropped out of school, up from fewer than a quarter of students a decade ago, according to a recent analysis of government data by think-tank Education Sector. College dropouts are also among the most likely to default on their loans, falling behind at a rate four times that of graduates.

With results like these, questions are rising regarding how access to higher learning prepares students once they are in enrolled in college. Some education experts have begun to argue that starting college-and going into debt to pay for it-without a clear plan for a diploma is a recipe for disaster.

"They have the economic burden of the debt but they do not get the benefit of higher income and higher levels of employment that one gets with a college degree," Jack Remondi, chief operating officer at Sallie Mae, the nation's largest private student lender, told the Washington Post. "Access and success are not linking up."

The Obama Administration says it is trying to address the issue by coupling its goal of better preparing high school students for higher education and new targets for graduation rates.

According to a 2009 study by Public Agenda, half of college dropouts said work to fulfill the rising costs of college was a major factor in their decision. Only a quarter said they spent too much time socializing.

The cost to the economy is roughly $500 billion. And although college dropouts make more than those with only a high school diploma, they earn about a $1 million less than college graduates over the course of their careers.

College enrollment has swelled by 38 percent during the past decade to more than 20 million, according to government data. And regulators are casting a wary eye on burgeoning market of for-profit institutions with low graduation rates and high student debt loans.

The Obama administration said it has made increasing the college graduation rate by 2020 one of its top educational priorities.

Still, education experts say that many students are simply not prepared for higher learning, and that many schools do not offer the guidance needed for many young people to succeed in college.