A masked student has his temperature checked before his first day of in-person school since the pandemic began in Los Angeles, Aug. 16.

Photo: etienne laurent/Shutterstock

The officials in charge of running the nation’s public schools had all summer—and $122 billion in Covid relief funds from Congress—to plan for the first day of school, so naturally chaos has ensued as students begin heading back to the classroom.

San Francisco, Miami and Dallas haven’t decided on a quarantine policy or what infection-rate threshold will trigger school closures. In New York City, home to the nation’s largest school system, principals are wondering how every student can return to in-person learning full-time while still adhering to social-distancing requirements. Mayor Bill de Blasio announced a vaccine mandate for all school staff, but teachers unions have vowed to challenge its implementation.

School in parts of the South started earlier this month, at least temporarily. Burbio, a website that tracks school openings, has already “identified over 100 school closures across 70 districts” because of Covid. Classes haven’t begun yet in the Northeast and Upper Midwest, so those numbers will almost certainly rise as the Delta variant runs its course, but why are school and health officials keeping parents in prolonged suspense about contingencies? Last year, we were new at this game, and the people in charge arguably deserved some slack. Not anymore.

The Rand Corp. has released the results of a nationwide parent survey on school hesitancy taken in July. Although Delta was already spreading by then, 89% of parents, including more than 80% of typically more hesitant black and Hispanic respondents, said they would opt for in-person learning for their children this year. Parents apparently understand the health risks, and they’re weighing them against the harm of another year of horribly substandard instruction via Zoom.

What these families need is detailed information on the criteria used to determine whether schools stay open. Instead, they’re being kept in the dark by bureaucrats and politicians. And they’re being toyed with by union honchos who don’t mind the uncertainty because it can be used as leverage to negotiate better pay and benefits as a condition of returning to the classroom.

Policy makers could also stand to be a little less cocksure about the “science” behind their recommendations. Last week, President Biden instructed the Education Department to “assess all available tools”—including the threat of civil-rights probes—for undermining governors who want to let parents decide whether their children will wear masks at school. For starters, Mr. Biden is butting into affairs best handled by state and local officials who understand the needs of their constituents and can be held accountable for their decisions. Even worse, the president and other supporters of mask mandates for pupils are pretending that the case for them is ironclad.

A New York magazine article last week reported on the findings of a “mostly ignored, large-scale study of COVID transmission in American schools” that was published in May by the Centers for Disease Control and Prevention. The study matter-of-factly called into question the efficacy of face coverings for children in schools. “These findings cast doubt on the impact of many of the most common mitigation measures in American schools,” the magazine reported. “Distancing, hybrid models, classroom barriers, HEPA filters, and, most notably, requiring student masking were each found to not have a statistically significant benefit. In other words, these measures could not be said to be effective.”

The article also noted that many European countries—including Britain, Italy, France, Switzerland and all of Scandinavia—“have exempted kids, with varying age cutoffs, from wearing masks in classrooms,” yet “there’s no evidence of more outbreaks in schools in those countries relative to schools in the U.S., where the solid majority of kids wore masks for an entire academic year and will continue to do so for the foreseeable future.”

The CDC study comports with the findings of Brown University economist Emily Oster and four co-authors, who analyzed student Covid rates in Florida, New York and Massachusetts during the 2020-21 school year with a focus on the effects of student density, ventilation upgrades and masking requirements. “We find higher student COVID-19 rates in schools and districts with lower in-person density but no correlations in staff rates,” they wrote in a paper published earlier this year. “Ventilation upgrades are correlated with lower rates in Florida but not in New York. We do not find any correlations with mask mandates.”

If some parents want to be extra careful and have their children wear masks, that ought to be their prerogative. But when empirical studies, along with the experience of so many other Western nations, cast serious doubt on whether a policy is having the intended effect, it’s no wonder so many frustrated Americans are now telling policy makers what they can do with their mandates.

Main Street: The CDC should scrap its confusing guidance and make Covid-19 vaccination the only priority. Images: AFP via Getty Images Composite: Mark Kelly The Wall Street Journal Interactive Edition