If this outcome had been known with perfect clarity back in the spring of 2020, what would the public response have been? Surely some would have objected to closures, including those who didn’t see the pandemic as much of a threat. But overall I don’t think that parents, teachers and administrators or political leaders would have been horrified at the trade-off. Given everything else being done at the time to reduce spread — citywide lockdowns, months of social isolation and canceled events and gatherings — I think that cost would have been widely seen as pretty manageable. Presumably many of these measures could have been managed more effectively, and perhaps applied in more targeted ways. But given how long the school disruptions lasted and how significant they often were, the declines seem impressively small. (And since teachers unions have gotten a lot of criticism for delaying reopenings — even though surveyed parents were also often reluctant to return to in-person school — it may be worth mentioning that the test scores suggest that given the circumstances, the country’s teachers managed relatively well, too.)

Third, the size of the effect varied considerably. In Colorado, where only 22 percent of students had a lot of in-person schooling, test scores declined by only 5.4 percentage points between 2019 and 2021. In Minnesota, where 24 percent did, the cost was higher: 10.6 percentage points. At the state level, it’s hard to even see clearly the relationship between school closures and pandemic learning loss, and when Oster breaks down the data into cohorts by levels of in-person schooling, the picture doesn’t grow all that much clearer. In Indiana, for instance, scores in “very low” levels of in-person instruction dropped by 10 percentage points in reading and about three in math, while those with “very high” levels of in-person school fell by about eight points in each. In Minnesota, schools with “low” in-person levels lost about seven points in reading and nearly 14 in math, while schools with “high” levels lost nine points and 13 points.

That said, several earlier and more granular studies have shown stronger correlations between remote learning and testing declines at the district level, which suggests that aggregating district data probably folds a whole lot of confounding variables into what was already a complicated-to-unpack equation — and that remote learning, though not the only factor, did have a significant and meaningful negative effect. Poverty certainly plays a significant role, too, exacerbating learning losses, as previous studies demonstrating the much higher costs of school closures in poor districts have also found. A similar dynamic applies with race, and while high-performing students suffered relatively small setbacks, low-performing students registered larger losses. Closer examinations yield an even more complicated picture: In a useful meditation on the testing data for KQED, Jill Barshay points out that reading scores were relatively stable through the pandemic, in urban school districts and across the West, while math declines were much more universal.

Fourth, we are already seeing a rebound effect, reflecting the fact that across the country, students appear to be learning at “normal” pace again. But the rebound effect is not as robust as one might have hoped, with some experts suggesting it will take three to five years to recover from the setbacks. Overall, Oster estimates, students have already made up about 30 percent of their pandemic losses, as measured by the 2022 tests, though again there is a range: Colorado recovered more than half of its losses, performing in 2022 only 2.6 percentage points behind its prepandemic baseline, whereas in Indiana, students recovered only about 10 percent of their losses, and this year were almost eight points behind. Which is to say, we don’t yet know how long-lasting these setbacks will be, but we know that they are shrinking. And perhaps there is something to learn from Mississippi in particular, where, according to the 2022 test results, students have already regained as much as 80 percent of their pandemic learning loss.

How does all this add up? Not all that neatly — which may be the most important point. Throughout the pandemic, we have conjured narratives out of messy experience, trying to extract obvious lessons or apportion responsibility when reality is more complicated and contradictory than is emotionally or ideologically palatable. In the summer of 2020, we railed against people running outside or going to lake parties, and then against those traveling home for the holidays, PCR result in hand. We talked about “Red Covid” — as it supposedly became a disproportionately Republican illness — when vaccination rates were never much higher and death rates never much lower among the poor, poorly educated and racially disenfranchised than among Republicans. Because we knew that vaccines significantly reduced individual risk, we used the phrase “vaxed and done” even as more vaccinated than unvaccinated Americans were dying. We worried about teenage depression when eating disorders may have been the biggest mental-health impact of the pandemic for adolescents.

And when it came to schools, we fought over the consequences of remote learning as though the present health and future well-being of an entire generation of students was on the line. What we are starting to see more clearly now is that those consequences, though worth reflecting on, were probably not as large as either side feared. “Students haven’t regressed,” Barshay emphasizes, comparing the dynamic to a cross-country road trip. “Imagine that students were traveling at 55 miles an hour, ran out of gas and started walking instead,” she says. According to testing data, “now they’re back in their cars and humming along again at 55 miles an hour. Some are traveling at 60 miles an hour, catching up slightly, but they’re still far away from the destination that they would have reached if they hadn’t run out of gas.”

Next time, we should try to do better. But all things considered, the best data we have at the moment suggest that school closures were probably a fog-of-war-style social and political stumble, not, as some have suggested, a “disastrous, invasion-of-Iraq magnitude (or perhaps greater) policy decision.” ​​

David Wallace-Wells (@dwallacewells), a writer for Opinion and a columnist for The New York Times Magazine, is the author of “The Uninhabitable Earth.”