Will mask mandate enthusiasts please confront the data?

On March 2, Texas Governor Greg Abbott made headlines by lifting the state’s mask mandate and removing all restrictions on business capacity.  The condemnation from public health authorities was swift.  Dr. Anthony Fauci stated that this move was “inviting” another virus surge.  CNN reported that Abbott faced a “torrent of criticism,” including from President Biden, who characterized Abbott’s move as “Neanderthal thinking.”

We are now, on March 23, three weeks out from Abbott’s decision.  Here are the data on cases in Texas, from the NY Times:

On March 2, the Times reported a seven-day average of 7,259 new cases per day; as of yesterday, the seven-day average is 3,714 cases per day.  Clearly, there is no sign of a surge; far from it, the number of cases in Texas has dropped by 49%.  Note that this is much steeper drop than the 17% national decline in cases over the same period, based on the NY Times data (64,469 cases/day to 54,190 cases/day).  

Mississippi eliminated its mask mandate and business restrictions on the same day as Texas.  Almost exactly like Texas, Mississippi has seen a 50% drop in the seven-day average of new cases from March 2 (582/day) to March 22 (293/day).  Here’s the plot:

Maybe three weeks is not long enough to see the predicted rise in cases?  Three other states lifted their mask mandates earlier:  North Dakota in mid-January, and Iowa and Montana in early-to-mid February.  Here are the plots:

Not a surge in sight; in all three states, there are fewer new cases per day now than there were when the mask mandates were lifted.  

What about states that never had mask mandates in the first place?  Surely, during the periods of the worst spread of Covid-19, mask mandates must have made some difference?  The following chart shows the number of Covid-19 deaths per 100,000 people as of March 22, 2021, by state (from Statista).  I have added the arrows to indicate the 11 states that never had mask mandates.

A couple of states without mandates have had a relatively high toll (Arizona, South Dakota), and a few states without mandates have had a very low toll (Nebraska, Idaho, Alaska).  The rest are in the middle somewhere.  Overall, there is no indication that the impact of Covid-19 has been greater in states that have lacked a mask mandate.  

One year into this pandemic, policies with regard to masks and other restrictions on personal and business activity do not seem to explain the variability in the prevalence of Covid-19 between states, nor do they seem to explain changes in prevalence over time.  This is not a new observation, as the almost identical impact in Florida and California, despite their very different approaches, has been much discussed, such as in this article from March 13: 

“Nearly a year after California Gov. Gavin Newsom ordered the nation’s first statewide shutdown because of the coronavirus, masks remain mandated, indoor dining and other activities are significantly limited, and Disneyland remains closed.  By contrast, Florida has no statewide restrictions. Republican Gov. Ron DeSantis has prohibited municipalities from fining people who refuse to wear masks. And Disney World has been open since July. Despite their differing approaches, California and Florida have experienced almost identical outcomes in COVID-19 case rates.”

One possibility, of course, is that mask mandates and business restrictions don’t have much effect on the spread of Covid-19 because people’s behavior is mostly governed by their own judgment and proclivities, whatever the official rules may be; however, there is at least some evidence that mask mandates do increase mask wearing.  The other possibility is that mask wearing itself is simply not very effective in preventing community spread, in the real world, contrary to what we have been told since near the beginning of the pandemic.  Indeed, the only randomized, controlled trial that I have heard of, which was carried out in Denmark, did not find a statistically significant reduction in Covid-19 cases due to mask wearing. 

Whichever of these explanations turns out to be right – or if both are partly right – an important question is whether the supporters of mask mandates and business restrictions will start to change their views about the efficacy of these measures or, if not, will be held accountable for them by the media.  I am afraid that there is little sign of this happening, yet.  On February 26, CDC Director Rochelle Walensky stated that “Now is not the time to relax restrictions.”  But why, exactly?  It is long past time for public health and other governmental authorities to point to the actual data demonstrating the efficacy of these restrictions.  They are often espoused as ‘common sense.’  Perhaps this is a correct characterization – it does seem like mandating mask-wearing and business closures should work – but we now have more than enough data to demonstrate whether they actually do. 

I’ll note that I would welcome any argument as to why the above data should not be taken at face value.  Please reply with a comment.  

I’ll also note, however, that we should all try not to cherry-pick data from a particular time, or a particular place, that are favorable to a case for or against mask mandates. For example, on December 4 Vox published a graph very much like the one above, but showing that many of the states without mask mandates had among the highest rates of new cases in the month of October. But why focus on October? Presumably because the data from this particular month happen to fit that article’s narrative. Indeed, these were not even the most recent data at the time of publication. As the plot in the present article clearly shows, states without mask mandates have not been hit particularly hard overall, which implies that we could have focused on other months when the states without mandates did better than average. The graph I’ve shown here covers the entire pandemic; we are not picking and choosing a time period that favors any one case.

Similarly, we should avoid cherry-picking specific comparisons that make a state’s policies look good or bad. I pointed out in a previous post that the frequent comparison of Sweden’s pandemic impact to the impact in Norway and Finland, which makes it look like Sweden’s less restrictive policies have been a mistake, is quite misleading, because Sweden’s pandemic impact has actually been quite typical for European countries.

Adrian Staub (astaub@umass.edu)

Thanks, as usual, to Rosie Cowell, Carlo Dallapiccola, and Dave Huber.

4 thoughts on “Will mask mandate enthusiasts please confront the data?

  1. Talking about mandates has no meaning without knowing about adherence to mandates in states that had them and mask wearing behavior in states that didn’t. I think population density and population characteristics such as age breakdown and health status of the population has to be taken into account. I find your general statements overly broad and misleading.

    • Thanks for your comment. What you are suggesting is that a more complex statistical model, taking into account variability between states in these other factors (e.g., population density, health status, etc.), would reveal that mask mandates do actually have some effect, though it is not visible in the simple state-by-state comparisons that I have shown above. That’s possible – but let’s see that evidence, then! I haven’t seen it. It’s high time to prove that mask mandates work, as opposed to simply assuming that they do.

      Adrian Staub

  2. I do agree with K. Smith above. I think it is important to look at the demographics and other data of the counties/states that are being affected to see and compare how states are doing with their mandates vs non-mandates.

    I am, or at least was originally, a supporter of the mask mandates, I believe the best thing I can do as a human being is do what I can to protect others around me and that includes masking and social distancing as much as possible. I don’t think that mask mandates work if the whole of the population isn’t working to eradicate the illness together. If in the beginning of the pandemic the whole of the population did everything in their power to mask/social distance/quarantine, I think we would see very different data than what we are seeing now and my guess is that we would be currently moving away from this illness at a substantially faster rate.

    At this point, since that did not occur and people actually actively fought against having to participate, we have prolonged the illness by not allowing it to die off before it could mutate into another variant. I believe that it can no longer be eradicated and thus we will have to learn how to live with it and adapt as a species. I think at this point it is a matter of pulling off the bandage and getting back to “normal” which will result in more deaths then I think was necessary.

    I would like to see an updated response to this article that looks at how these states listed, and other states that dropped their mandates and then reinstalled them, are doing. I know where I live in Oregon, when mandates were lifted we didn’t see a lot of change in levels until 2 months after the lifting of the mandates. Currently, our infection and death rates are the highest they have ever been.

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