Editor’s note: This commentary is by Stan Greer, senior research associate for the National Institute for Labor Relations Research.

It’s been more than nine months now since politicians across America “temporarily” shut down K-12 schools in their jurisdictions as part of an extraordinary effort to combat the spread of COVID-19.

Last summer, as more and more became known about COVID-19, there emerged a strong, worldwide consensus among public health specialists that schoolchildren face less risk from COVID-19 than they do from the flu and that schools are not important vectors of the pandemic.

Nevertheless, many if not most K-12 public schoolchildren are still not attending school in-person this winter.  And the principal reason why is the inordinate power wielded by teacher union bosses over school operations in the vast majority of the 50 states.

With few exceptions, union officials have fought school reopenings tooth and nail. Their fierce resistance would be reasonable if COVID-19 posted a major risk to schoolchildren or to educators themselves.

But the fact is that the risk to kids is very low. Children aged 5-17 are far less likely to be hospitalized for COVID-19 than they are for the seasonal flu, according to Center for Disease Control and Prevention statistics. Children are also far less likely to die from COVID-19 than they are from the flu.

It’s also true, as an article published in the scientific journal Nature in October noted, that young children infected with COVID-19 are far less likely to transmit it than adults are, and adolescents are no more likely to transmit this disease than adults are. “Data gathered worldwide,” the article stated, “are increasingly suggesting that schools are not hot spots for coronavirus infections.”

Teachers who offer instruction to children in person are for that reason almost certainly no more likely to be infected with COVID-19 than people who work somewhere other than at a school.

While there is minimal, if any, health benefit from keeping schools shuttered, the educational costs are high.

In school districts where classes continue to be on-line only, there is ample evidence the quality of instruction is lower than it was before. Students are failing more classes. And more kids are dropping out of school altogether.

As the evidence mounts that their kids are being denied the benefits of in-person instruction for no good reason, parents in many school districts are demanding that schools reopen, and this winter more and more city and state elected officials seem to be heeding them.

That infuriates union bosses like Becky Pringle, who assumed the presidency of the mammoth National Education Association (NEA) union last September.

According to Pringle, school officials, mayors and governors who fight to keep schools open, or reopen them, while making good-faith efforts to ensure they operate safely, are “bullying” teachers “into returning … to classrooms.”

Even as Pringle and other powerful teacher union bosses insist that their members be fast-tracked for COVID-19 vaccinations, they also insist their members should not be expected to return to the classroom even after they have been vaccinated.

Expressing sentiments undoubtedly shared by many parents of school-aged children around the country, National Review correspondent Jim Geraghty has noted that Pringle’s bullying crack epitomizes how “teachers’ unions are quite content” with the “status quo of students attempting to learn from home.” This attitude, says Geraghty, is “worthy of scorn.”

As infuriating as the hostility of Big Labor bosses to school reopenings is, it wouldn’t matter much if politicians in more than 30 states hadn’t passed laws granting union bosses monopoly-bargaining power over how teachers in public schools are compensated and managed.

These special-interest statutes have turned the NEA and the American Federation of Teachers unions into political juggernauts across the U.S., even in states like North Carolina and Texas that have sensibly refused to adopt government-sector monopoly-bargaining laws.

Counterproductive state labor laws are the key reason why school reopenings in cities like Chicago and New York will be an uphill battle.  And concerned parents and everyone else who cares about the future of education in America should favor repeal of all state monopoly-bargaining laws.