More than 44 million Americans have taken out student loans to pay for higher education, in the process incurring around $1.4 trillion worth of debt.

It's a symbol of the importance society places on higher education. As it turns out, the financial benefit of earning a college degree,might be overstated. That argument is raised in a new report published by The Economist, which analyzed the post-school earning potential of those with degrees, versus those without.

"Policymakers regard it as obvious that sending young people to university will boost economic growth and social mobility," the report noted. "As technological change makes new demands of workers, it seems plausible that more will need to be well-educated. A degree is a way for bright youngsters from poor families to prove their abilities."

The main evidence cited by policymakers, though, is something called the "graduate premium," defined as a return of investment on education, or, "the difference between the average earnings of someone with a degree and someone with no more than a secondary-school education," according to the report.

In the U.S., that premium is about 15 percent per year, according to New York Federal Reserve data. That means an investment equal to the cost of tuition and other education-related costs would have to earn 15 percent annual interest before matching the average value over a working life of gaining a degree, The Economist explains.