The National Review on Wednesday published a piece concluding the mandate has had little effect on the spread of the virus. “After Mandating Masks Outdoors, Oregon’s Active COVID-19 Cases Increased 73 Percent,” reads the headline.
The stat is tailor-made to spread on the right, and it has begun doing so. Conservative pundits and sites are promoting it as evidence that mask mandates — and particularly ones for the outdoors, where the coronavirus isn’t transmitted as easily — are overzealous and ineffective.
The problem is that the data spotlighted doesn’t necessarily say what it seems.
Notice that the headline says “active” cases. The traditional measure for how coronavirus mitigation is progressing is new cases, but this focuses on active ones — i.e., people who still have the coronavirus, regardless of when they were infected.
And that can be quite misleading. Mild cases of the coronavirus can last one to two weeks, while more severe cases can linger for upward of six weeks. In other words, if you’re seeing a rise in new cases, you’re probably going to see a rise in active cases for weeks afterward, because the newly infected take a while to recover. That doesn’t necessarily mean things aren’t getting better overall.
And that’s what has happened in Oregon. The mask mandate was instituted Aug. 24, because the state was seeing a spike in cases. It went from a seven-day average of about 1,000 daily new cases in early August to more than 2,000 when the mandate was instituted. And the rate stayed north of 2,000 for a while, meaning there were suddenly significantly more people who had recently been infected who needed to recover, relative to Aug. 24.
Which brings us to that more traditional and telling measure of how mitigation is working: new cases. And it turns out the seven-day average is actually down significantly — about 21 percent since Aug. 24, in fact.
Take a look at this chart from the Oregon Health Authority. Aug. 24 came right before the current peak of average new cases, and they’ve since fallen to an average of about 1,600.
Daily deaths have also leveled off and even declined of late. While the National Review piece notes they continued to rise even shortly after the mandate began, that’s to be expected. People who die often don’t do so right away, but two to eight weeks after infection, making this a lagging indicator of mitigation.
A good rule of thumb is to look at deaths about two or so weeks after new cases, and sure enough, deaths peaked around an average of 20-25 in early to mid-September, before falling to an average of 16 today. (These numbers are small enough that there’s likely some statistical noise involved, but the seven-day average has declined after that lag period.)
The National Review piece does mention the decline in new cases, before adding in the next paragraph, “Nonetheless, the fact that the state with the most far-reaching masking requirement has seen a 73 percent increase in active cases in about a month is a vivid illustration of the limitations of masks.”
Mostly, though, it seems to be a reflection of an already-existent spike in cases, which happens to have leveled off and then fallen shortly after the mandate was instituted.
Does that mean the curve has flattened and then declined because of the mandate? Not necessarily. Many things factor into increases and decreases, and even health officials who encourage masks have been circumspect about how much protection they offer. It’s quite likely that the flattening and decline of the case numbers owes more to other factors — changes in weather, people changing their other habits in light of the increase in cases, etc.
But to emphasize the active-case data in Oregon as some kind of an argument against a mask mandate is certainly a curious one, when other, better data — especially new cases — seems to suggest the situation has gotten under control, to some extent. (Hospitalizations have also declined since Aug. 24.)
The author of the National Review piece, Jim Geraghty, expanded on his argument Thursday when he got pushback. He noted that he has said masks probably help somewhat, but that “you can’t really mask your way out of this problem.” He also noted that people won’t always mask around their family members and in other contexts, which allows the virus to spread.
Which is all true. But nobody has ever held masking out there as a silver bullet. It’s a relatively easy mitigation technique that can slow the spread, hopefully in combination with other things that are far more effective, like vaccines.
Whether they should be mandated is a valid debate. But in that debate, we shouldn’t focus too much on anecdotal evidence in one state over a short period of time, and Oregon is hardly the case study against such mandates that some are suggesting.