I want to elaborate on why ignoring urban/rural in Kansas mask study is a big deal bordering scientific malpractice:

Smaller counties are more likely to be no-mask. They are also much more sensitive to case changes in % terms.

The authors use % change as their criterion. (1/7) https://twitter.com/covidtweets/status/1330734764513497088

The authors say "... counties were compared to themselves over time, allowing for the control of constant county-related characteristics (e.g., urbanicity or rurality) that might otherwise confound a comparison between mandated and nonmandated counties." This is BS... (2/7)

When you use percentages as the criterion, smaller counties will see bigger jumps after a small absolute increase in cases. This is basic math. Yet all the Ph.D.s who have written this seem to be ignorant of this fact. (3/7)

Look at the counties below, all no-mandate except for Cherokee. Avg. population is 4,383. Average case increase between Aug11-Nov20 is 5,000%.

You read that right, five-thousand-percent!

Comanche County saw an increase of 4,000% - their cases increased from 1 to 40... (4/7)

The study uses cases within a time period instead of cumulative, which alleviates this to some extent, but still, a small county is more likely to have 2 cases one week and 10 cases the next (500% increase). (5/7)

That's why I excluded these small counties in my analysis below, along with major urban counties. That's the only way to minimize the bias caused by urban vs. rural confound.

Yet, the CDC publishes this as a scientific study.... (6/7) https://twitter.com/covidtweets/status/1330734767554359296?s=20

I would be ashamed to put my name on this as a scientific publication. Yet here we are. It is published by the CDC, none the less...

I guess this is the norm given the standards of scientific inquiry in 2020... (7/7)