Student enrollment at colleges fell once again in the fall, a new report has found, prompting some to worry whether the declines experienced during the pandemic could become an enduring trend.

The National Student Clearinghouse Research Center on Thursday said undergraduate enrollment in fall 2021 dropped 3.1 percent, or by 465,300 students, compared with a year earlier. The drop is similar to that of the previous fall, and contributes to a 6.6 percent decline in undergraduate enrollment since 2019.

That means more than 1 million students have gone missing from higher education in the wake of the coronavirus pandemic, according to the Clearinghouse.

Even as campuses have largely reopened and returned to some semblance of normalcy, people are not pursuing credentials at the same rate as before. Experts worry that the unabating declines signal a shift in attitudes about higher education and could threaten the economic trajectory of a generation.

“The longer this continues, the more it starts to build its own momentum as a cultural shift and not just a short-term effect of the of the pandemic disruptions,” Doug Shapiro, executive director of the National Student Clearinghouse Research Center, said in an interview. “Students are questioning the value of college. They may be looking at friends who graduated last year or the year before who didn’t go and they seem to be doing fine. They’re working; their wages are up.”

Job openings are at near record highs, and the lure of what many economists say is a job seekers’ market may be siphoning off would-be students, especially adult learners. Indeed, one of the sharpest enrollment declines this fall was among people 24 and older, particularly at four-year colleges, according to Clearinghouse data.

The number of associate-degree-seeking students enrolled at four-year institutions plummeted in the fall, down 11 percent from a year ago. The drop was less severe at community colleges, where the decline in head counts was 3.4 percent.

Still, public two-year colleges remain the hardest-hit sector since the start of the pandemic, with enrollment down 13.2 percent since 2019. Leaders of community colleges have said some of their students struggled to pivot online at the start of the health crisis because of spotty Internet access, while others took a step back from school because of family obligations.

Because community colleges educate a large share of students from low-to-moderate-income families, higher education experts worry a continuation of enrollment declines could erode their earnings potential. Shapiro is broadly concerned that tepid enrollment throughout higher education will impact the nation for years to come.

“There’s a great deal at stake,” he said. “We have to get students back on track, re-engage them.”

There are some promising signs in the data. Freshman enrollment stabilized in fall 2021 following a precipitous decline the previous year, even though it remains 9.2 percent lower compared with pre-pandemic levels. Private nonprofit four-year colleges are driving the increase in enrollment, with an increase of 11,600 students, according to Clearinghouse data.

Only four states — Arizona, Colorado, New Hampshire and South Carolina — witnessed an increase in total fall enrollment. Head counts at colleges and universities in Maryland fell 5 percent, largely driven by depressed enrollment at community colleges. The same trend prevailed in Virginia, where total fall enrollment dipped 1.2 percent because of public two-year schools.