Remember, Remember the Spike of November

Akshually, late October, but why pass on a gratuitous Guy Fawkes reference?

Anyway, one thing I’ve seen in many articles is the claim that Thanksgiving travel led to a massive surge in COVID-19 cases. The new case data, however, don’t indicate this, but I’m getting ahead of myself.

Early on in the pandemic, the early figures of cases, either daily new cases or cumulative cases, were constructed using a log scale. While this was useful for understanding if the rate of increase of new cases was increasing or decreasing, there are concerns that the public might be confused by this depiction: when the distance on the vertical axis between 10 and 100 cases is the same as the distance between 100 and 1,000, it might be difficult for people unfamiliar with this depiction to realize that things are much worse in absolute terms. Very quickly, graphics departments started using absolute values on the vertical axis to convey the urgency of the situation. Which is good!


Consider this chart of the one-week average of new daily cases for Washington D.C.:

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It looks like there’s a big Thanksgiving week effect. But now transform the data to a log scale and…

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…it doesn’t look like that at all. There’s a regular and increasing trend, with some variability, that definitely starts in late October, as noted by the red arrow. It’s not just D.C. either. Here’s California, where article after article blames Thanksgiving travel for that state’s woes:

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Massachusetts did have a plateau right before Thanksgiving, but it had a fairly reliable and ongoing increase in cases starting in September.

So if it’s not Thanksgiving–not that traveling around the country helped at all–then what was it? My speculative hypothesis is we were cursed with nice weather. If ever we needed a grey, shitty, rainy, and windy fall, it was this year. Instead, most parts of the U.S. had really nice weather (#NotAllParts) throughout much of the fall. That leads to people going out to restaurants and engaging other forms of maskless socializing, when we really needed people to stay the fuck at home.

Like I said, that’s just speculation, but I don’t think we can blame Thanksgiving entirely. The problem began weeks before. Unfortunately, exponential growth is hard to see clearly until it’s too late.

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1 Response to Remember, Remember the Spike of November

  1. Pingback: The Fall Surge Is Finally Noticed, If Barely | Mike the Mad Biologist

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