If masks stop coronavirus, why no discontinuity in the numbers?

Masketologists have declared victory against coronaplague. If a population of humans is ordered to wear masks, coronavirus will pack up and go home. Example: “Identifying airborne transmission as the dominant route for the spread of COVID-19” (PNAS) and one of the less hysterical popular media summaries.

[6/18 update from the Department of Coronascience is Settled: researchers from Stanford, John Hopkins, and University of Colorado say that the above PNAS paper should be retracted. “While we agree that mask-wearing plays an important role in slowing the spread of COVID-19, the claims in this study were based on easily falsifiable claims and methodological design flaws”]

I was fully prepared to believe this, since it is consistent with my idea that whatever people are doing in Japan, China, Korea, and Taiwan is probably the right thing to be doing. However… the governor of Massachusetts imposed a strict mask law that was effective on May 6. Faith in the Church of Shutdown’s Ritual of the Mask becomes a little tougher to sustain when looking at stats from the New York Times:

If masks are the way to slay the Covid-19 dragon, why isn’t there an observable discontinuity in these curves as a result of the restrictions imposed on May 6? If anything, it looks like there was a bump in cases followed by a bump in deaths roughly correlated to a change on the May 6 date.

Maybe the answer is that masks do work, but the state reopened in early May and therefore the viral spread from reopening canceled out the viral suppression from masks? Definitely not! From the License Raj:

Construction and manufacturing were allowed to reopen, “with restrictions, some capacity limitations, and a staggered start”, beginning on May 18. There was no significant change until May 25 (hair salons) and June 8 (hotels, some childcare (with masks on children older than 2; see the happy preschooler below), retail with occupancy limits).

The anti-Karen wrote:

What I don’t get: If masks work, why aren’t we back at work? If masks don’t work, why are we being asked to wear them?

This mask-loving Karen wonders:

If masks work, why don’t we see a collapse in “the curve”?

Readers: Should we believe “science” or our own eyes looking at the NYT graphs? I picked Massachusetts because that’s where I live (unwisely, it seems). Is there another state that adopted a mask law and in which the coronavirus waved a white flag and packed up?


8 thoughts on “If masks stop coronavirus, why no discontinuity in the numbers?

  1. There may be ‘laws’ on masks, but from my personal observations in some parts of Colorado, enforcement is at best lackadaisical, and compliance is weak. Similar to speed limits.

    A friend who has had to travel lately a bit says there is a great deal of variation across the country.

  2. Paul: At least until the Black Lives Matter protests started, I would have said that compliance in Massachusetts was quite high, nearly 100 percent inside the “essential stores” (I didn’t check into the essential marijuana shops, but I was a regular at Home Depot, Costco, Target, and some grocery stores). Cambridge had its own “masks on the sidewalk and in parks” addition to the statewide rule. Observed compliance was very high among white and Asian residents in the middle class or above.

  3. You are using the wrong curve if you want to see things that happened. You don’t want the curve that reports the number of cases by day of report. You want the curve that reports the number of cases by the date of test (or date of symptom onset if that is known). That gets rid of much of the delay that makes it hard to see the correlations you are looking for. https://drive.google.com/file/d/1lLOmidtJ6D-tb7fFp0KPiuge8TKpgrBD is page 5 of the MA daily dashboard.

    The number of cases has been falling dramatically since the beginning of May. Has it been falling faster since May 7? Maybe. We don’t know exactly which of the interventions has helped, but it’s definitely getting better.

    Furthermore, everyone that is wearing a mask now was wearing masks before May 7, so why would you expect to see any kind of discontinuity.

    There is some promising evidence that masks give you almost all the benefit of a full shutdown. But due to the nature of science, it’s too early to be state that such a theory is well supported.

    Also, it’s clear that the NYT journalism isn’t great. If you want to understand something in detail, you’re going to have to work a little harder.

    I’m concerned that as long as you frame things as “believe” and “church” you will not be able to understand science or even engineering.

  4. Saw an interesting video from a total kook on twitter. It purports to show Brazilian Parliamentarians forcing their way into a hospital that claimed 5000 cases and 200 dead from the Corona. The hospital was empty.


    If you will recall, I predicted that Brazil would see the dead actually rise from the grave as a result of the Corona.

    Quad est demonstrandum for the WIN, baby!

  5. law = compliance?

    Serious answer: "work" in this context means "reduce the probability of transmission". Masks reduce the probability of transmission. Distancing by 6 feet (or preferably more) reduces the probability of transmission. Doing both reduces the probability of transmission EVEN MORE.— Carl T. Bergstrom (@CT_Bergstrom) May 24, 2020


  6. Walking around Deluxebury yesterday mask compliance among the beautiful and well off was lower than lesser towns. Only the old were wearing masks, middle aged, younger, and their kids were smiling free.
    Masks are gross and provide zero protection from corona. Besides no one is properly wearing the masks spend a couple of minutes outside of any store and watch the touchy touchy soggy soggy masks.
    Forget trying to parse the saints err scientists use your own brain.

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