Exponential growth and epidemics

https://www.youtube.com/embed/Kas0tIxDvrg

Kas0tIxDvrg
A good time for a primer on exponential and logistic growth, no?
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Data source: https://www.worldometers.info/coronavirus/coronavirus-cases/#total-cases

Some have (quite rightfully) commented on how you shouldn’t look at the R^2 of linear regressions on cumulative data since even if the changes from one day to the next are completely random, the totals they add up to wouldn’t be independent of each other. Since the derivative of an exponential should also be an exponential, we could instead run the same test on the logarithms of the differences from day to day, which in this case gives R^2 = 0.91.

While this video uses COVID-19 as a motivating example, the main goal is simply a math lesson on exponentials and logistic curves. If you’re looking for a video more focused on COVID-19 itself, I’d recommend taking a look at this one from Osmosis: https://youtu.be/cFB_C2ieW5I

Extrapolation xkcd: https://xkcd.com/605/

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If you want to check it out, I feel compelled to warn you that it’s not the most well-documented tool, and it has many other quirks you might expect in a library someone wrote with only their own use in mind.

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