BOSTON — After a decade of relative stability, COVID has wreaked havoc with Massachusetts public-school enrollments, and the U.S. Department of Education projects more declines by 2030, according to a new study published by the Pioneer Institute.

The figures should serve as a warning to vulnerable districts that they must be prepared for the financial, staffing, and facilities impacts that may accompany substantial drops in public-school enrollments.

“COVID triggered a significant enrollment drop, and most of those students haven’t returned to public schools. Declines are likely to continue through the current decade,” said Ken Ardon, author of “Enrollment in Massachusetts Public Schools, COVID and Beyond.”

Previous Pioneer reports in 2008 and 2012 found that statewide public-school enrollment fell by 35,000 students over a decade, or about 0.5% per year, with the biggest declines in Western Mass. and Cape Cod.

Between 2010 and 2019, overall state enrollment was stable, although 68 cities and towns lost more than 20% of their students and 33 saw enrollment rise by more than 10%.

Patterns were more difficult to deduce during the 2010-19 period. Small districts were slightly more likely to lose students, while growth was more generally found in the Boston area and on Nantucket and Martha’s Vineyard.

COVID put an end to the relative stability. Between October 2019 and October 2020, statewide public-school enrollment fell by 31,000, or 3.3%. It declined by another 0.4% in the following year, and increased by just 2,200 students, or 0.2%, between October 2021 and October 2022. It’s clear that most of those who left have not returned.

The decline was largest among the youngest students; pre-K enrollment dropped by one-third, and kindergarten enrollment fell by 12%. White enrollment fell at three times the rate of non-white students. Pre-K and kindergarten enrollment has rebounded, but the decline is now beginning to make its way through middle grades. It’s not clear what happened to the students who left public schools during the pandemic, but there is some evidence that most of them switched to home schooling.

The U.S. Department of Education projects that K-12 public education enrollment in Massachusetts will shrink by 40,000, or 4.5%, by 2030. The data suggest that enrollment declines may be steeper in Western Mass. Construction of new housing or changes in migration could prevent some of the declines, but vulnerable school districts should be prepared for substantial drops.

Click here to read the full report.