KANSAS CITY, Mo. —

Millions of students in two- and four-year colleges are finding themselves clamoring for competitive internships, seeing them as must-have resume builders and keys to coveted jobs.

But just as the perceived value of internships has grown, so too have questions over who benefits most from the arrangements. While internships can hold great value as career starters, they also can create an environment — with college students hungry for jobs and employers able to feed that desire — that’s ripe for exploitation.

Few doubt the importance of internships to college students, even as the economy moves further out of the recession’s shadow. While unemployment for those ages 25 and older stands at 4.5 percent, the federal Bureau of Labor Statistics says it’s more than double that, 9.6 percent, for people ages 20 to 24. It’s triple, 15 percent, for 18- and 19-year-olds.

PAID OR UNPAID

Not all internships are created equal. Nor are all internships equal in their power to generate future jobs.

One of the biggest determining factors is whether an internship comes with a paycheck.

The National Association of Colleges and Employers’ 2014 student survey included 44,000 responses from students, including 10,210 from seniors getting bachelor’s degrees at nearly 700 colleges and universities.

Nearly 61 percent of the 2014 graduates had internships before they graduated, the report said. Slightly more than half of those who had an internship, either paid or unpaid, received job offers before they graduated.

But data collected over the last four years comparing the results of paid internships to unpaid internships to having no internship at all have repeatedly turned up the same result: Students with paid internships did far better in the job market than those with unpaid internships.

Students with unpaid internships, in fact, generally did no better than students who graduated having had no internship.

In the 2014 report, students with paid internships came out better on job offers in every sector: for-profit companies, nonprofits, government agencies.

Students with paid internships from for-profit companies had the best outcome: 65 percent of those with internships got offers before graduation.

Unpaid interns, on the other hand, fared comparatively poorly. No matter which sector, only about 40 percent of unpaid student interns received job offers before graduating.

That outcome is a statistical wash with that of peers with no internship at all. Among non-interns, 39 percent received job offers before graduating.

Starting salaries for those who had an unpaid internship, he said, not only tend to be lower than for those who once held paid internships, but they also tend to be lower than for those who had no internship.

Ending up in court

Unpaid internships can cost employers too. High-profile cases regarding the legality of unpaid or even low-paying internships have been finding their way before judges and juries.

The U.S. Department of Labor publishes six guidelines that for-profit companies must meet to hire unpaid interns. Among them: Internships are for the benefit of interns, not employers; interns do not displace other workers; and interns receive career training of a sort that might further their educations.

Going for broke

Many interns know the deal when they take their jobs.

Long hours, hard work, maybe the possibility of a job. And even if not, the possibility of making connections and earning goodwill that could lead to something else.

Nick Restivo, 25, knew that he’d be working hard last year as a sales intern for the Kansas City T-Bones baseball team.

The organization is known for putting its 40 or so seasonal interns through their paces from May to September. When the team is out of town, work slows. But when the T-Bones are playing at home, the college students can find themselves at the ballpark for 12 hours or more a day.

Working unpaid for college credit while he got his master’s degree, Restivo said he made money by also working 12-hour shifts, often on Saturdays and Sundays, at a fast-food restaurant.

“I’m a sports nut,” Restivo said. “I knew when I graduated I wanted to get into the sports industry.”

After his internship last year, he now has a full-time job in the T-Bones front office as a group sales associate.

His unpaid internship paid off.