The new school year in 2021 will hopefully bring learning back to real classrooms. But a return to normalcy also means resumption of the war over charter schools.

Those are tax-funded public schools run by private organizations. There are now 7,400 charter schools with 3.3 million students in the United States. The successes of the 25 percent of charters that outperform traditional public schools in reading and the 29 percent that outperform in math provide useful lessons for how all schools can improve.

Many powerful people and organizations, including teachers unions, don’t like charters, which usually are not unionized. They want to restrain or eliminate them. This includes President-elect Joe Biden, who, along with the Democratic Party, proposes giving local school boards the power to block new charters.

That would cripple the charter movement, because most school boards see charters as unnecessary competitors for students. Teachers unions do good work. Some of the best teachers I know, including my mom, have been members. But unions have yet to give any good reasons for why creative teachers should not be able to start independent public schools.

A new study by University of Arkansas scholars reveals that despite good results, charters have fallen far behind regular schools in financial support. Charter critics often say charters are draining money from regular schools, but the latest figures show they haven’t been very successful at that.

The University of Arkansas study by Corey A. DeAngelis, Patrick J. Wolf, Larry D. Maloney and Jay F. May looked at 18 urban areas. Charters in those locations received an average of $7,796 less per pupil than traditional public schools in the 2017-2018 school year. The scholars said this 33 percent gap was “the largest funding disparity ever discovered by our research team.”

Charter critics might applaud that gap and pray it gets even larger, but they have a problem. Millions of parents like the charters their children attend. “An examination of charter school achievement effects in 41 large metropolitan areas across the country showed that urban charters consistently boosted student achievement and the gains from disadvantaged backgrounds have been large,” said the University of Arkansas study authors, citing research by Stanford University’s Center for Research on Education Outcomes (CREDO).

A recent study by M. Danish Shakeel and Paul E. Peterson in the journal Education Next found that “student cohorts in the charter sector made greater gains from 2005 to 2017 than did cohorts in the district sector,” according to data from the federally funded National Assessment of Educational Progress.

The University of Arkansas study looked at regular schools and charter schools in these areas: Atlanta; Boston; Camden, N.J.; Chicago; Denver; Detroit, Houston; Indianapolis; Little Rock; Los Angeles; Memphis; New Orleans; New York City; Oakland, Calif.; Phoenix; San Antonio; Tulsa; and Washington.

A separate study has come out about that last city, our nation’s capital, where I started covering charters during their infancy in 1997. That study’s author is Terry Eakin, a real estate developer active in several educational ventures, including D.C. Prep, one of the highest performing charter networks in the city.

His figures show that the two systems, D.C. traditional schools and D.C. charter schools, in some ways look like twins. They have almost the same number of students: 51,060 for traditional and 43,556 for charters in 2019. They are also similar in the percentage of students considered at risk because of family troubles including poverty — 45 percent for traditional schools and 47 percent for charters.

Yet the D.C. charters appear to be doing better with those kids. Stanford’s CREDO researchers reported in 2013 that the average D.C. charter student gained the academic equivalent of an extra 72 school days in reading and 101 school days in math compared with the average student in the traditional system. Eakin said the D.C. charters were also getting about $14,000 less per student from taxpayers in 2015 than the traditional schools. That contributed to a big difference in average annual pay: $55,209 for traditional teachers and $45,751 for charter teachers.

I conclude from these findings that traditional schools should study how charters have managed to do better with less money and follow their lead. Sadly, the University of Arkansas study, the Education Next study and the Eakin study don’t mention this possibility, perhaps because the idea is too simple-minded to survive in rough-and-tumble U.S. politics.

Instead, the unions want local school boards to have the power to nix more charters. They can’t do that under D.C. law, but they can in Virginia. The Fairfax County School Board, for instance, has been able to prevent the creation of a charter secondary school led by one of the school district’s best teachers by praising the idea but doing nothing for it.

The Fairfax County schools superintendent told me in 2015 that they just couldn’t afford “siphoning off” funds for a charter school, ignoring the fact that the district would still have to pay to educate those same students in its regular schools.

The D.C. school board would have similarly killed the city’s first charters in the late 1990s if it had the power to do so. I covered a D.C. board meeting at the time, and several members were seething about not being able to block those annoying new schools that parents found so interesting.

Thankfully, when schools reopen next school year, parents will still have a chance to enroll their children in successful charters. At a time when students will need all the help they can get to catch up on what they missed this year, blocking new charters that have longer school days and talented teachers seems to me one of the worst ideas ever.