The concept of the “student swirl” was conceived in the 1980s to describe undergraduates who moved among institutions before earning a bachelor’s degree. Students who transferred often did so because they made a poor initial match with an institution, or encountered academic or financial problems along the way.

But now there is a growing body of evidence that students might be making a deliberate choice to transfer institutions as part of their pathway to a bachelor’s degree.

First there is the report released last week from the National Student Clearinghouse Research Center, which found that more than one-third of students transfer at least once before earning a bachelor’s degree. Of those who switched colleges, almost half transferred more than once.

Second there is research from Sallie Mae’s annual survey, How Americans Pay for College. According to that report, students who have a wide variety of choices about where to go to college are beginning their studies at a community college. Twenty-five percent of students from households earning $100,000 or more now attend community colleges, up from 12 percent just five years ago, the survey found. In the past, many of those students likely started and finished at a four-year college.

As the price of four-year colleges continue to rise and family incomes stagnate, parents and students are taking another look at community colleges as a good place to start. Two-year colleges offer a variety of advantages including lower tuition rates, sometimes smaller classes, and the chance to explore majors before committing to a specific one.

But the problem is that most two- and four-year colleges fail to recognize that students want more structured 2+2 pathways to a four-year degree. With the exception of a handful of partnerships in a few states, articulation agreements between two- and four-year colleges are hit or miss. The gold standard remains the Direct Connect program in Orlando, which guarantees admission to the University of Central Florida for graduates of nearby two-year institutions, such as Valencia College. Community college students who have transferred to UCF now make up 48 percent of those who are awarded bachelor’s degrees.

Without a strong agreement like the one in Orlando, there are too many hurdles for ensuring a smooth pathway for students who want to set out on their college career by attending two institutions to earn their bachelor’s degree. As a result, too many students give up. Although some 80 percent of community-college students say they plan to transfer to earn a four-year degree, only about 40 percent do, and only 17 percent actually earn a bachelor’s degree within six years.

Many of those students end up with a bunch of credits and no degree. Across the country, there are nearly 45 million Americans 25-years-old and above who have some college but no degree. That’s more than one in five adults. In many ways, those people are no better off financially than high-school graduates who never attempted college at all.

What’s worrisome is that some 2.2 million people under the age of 30 have earned at least half the credits they need for a bachelor’s degree, according to the National Student Clearinghouse Research Center. Twenty-somethings represent the biggest slice of the population by far who have that many credits but no degree.

Leaders of four-year colleges maintain that students need to spend four years on their campuses in order to receive the full benefits of the bachelor’s degree. But many institutions have little proof that four years leads to better student engagement and outcomes than the final two years of a degree. Four-year colleges, of course, have an enormous financial incentive to persuade students to spend four years of tuition on their campus rather than transfer in half of their credits.

But as students of all kinds see the route to a bachelor’s degree running through a community college, four-year colleges that provide an easy pathway for students on that road will increasingly have a competitive advantage in the admissions market for high-school graduates in the future.