The Pew researchers found that the vast majority of millennials with at least a college degree thought that their degrees had already paid off, even if they had borrowed money to go to school.
Avery said his research has shown that taking on some student loan debt is still generally worth the reward of education, as long as the student borrows a reasonable amount of money and earns a degree. But it can backfire if the student drops out and ends up with high debt but little education to show for it. That's especially common among people who go to for-profit universities, he said.
Other research has shown that what you study in college, and what you plan to do after college, also makes a big difference.
A Census report on lifetime earnings, which used data through 2011, found that a person with a college degree can expect to earn about $2.4 million over a 40-year career. That's more than $1 million more than a person with just a high school diploma can expect to earn in that period, according to the analysis of median full-time salaries.
But, the Census feport found, the pay boost was generally much stronger for people in fields such as engineering or computing than for college graduates in the education or service professions.
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Still, Avery noted that there are other benefits to a college degree. He said other research has shown that college graduates are happier in their jobs than those without a college degree, even if their earnings aren't that different. He said that's evidence that there are other career benefits to going to college, such as the ability to land a more pleasant job in a field you enjoy.
The Pew data reinforced that as well. The center's survey of about 500 currently employed 25- to 32-year-olds found that 53 percent of those with a college degree were very satisfied with their jobs, compared with 37 percent of those without a college degree.
—By CNBC's Allison Linn. Follow her on Twitter @allisondlinn and Google or send her an email.