R is a dimensionless constant. Infections is measured in individuals. So what the f*ck are the units then?
This is the kind of bullshit we call “mathiness” in our forthcoming book.
H/t @merz.
This is the kind of bullshit we call “mathiness” in our forthcoming book.
H/t @merz.
From the book: "Mathiness refers to formulas and expressions that may look and feel like math—even as they disregard the logical coherence and formal rigor of actual mathematics."
(Admittedly the shock-and-awe factor is minimal here in this sum of two quantities)
(Admittedly the shock-and-awe factor is minimal here in this sum of two quantities)
"When an equation exists only for the sake of mathiness, dimensional analysis often makes no sense."
If Boris claimed the threat level was a *function* of these two quantities, fine. But to say it is a *sum* makes zero sense.
If Boris claimed the threat level was a *function* of these two quantities, fine. But to say it is a *sum* makes zero sense.
Now possibly R in Boris's equation is not the familiar R0 or Re. To make sense, though, it has to have units of "individuals" — and thus cannot be a rate.
If it *is* R0, it's interesting that an R of one with 15 cases would be scarier than an R of 10 with five case.
If it *is* R0, it's interesting that an R of one with 15 cases would be scarier than an R of 10 with five case.
Finally, bonus points for having literally two variables with letter names (rate of infection, response level), and picking capital R for both of them.
I thought it would be hard to top epidemiologists' dual use of R in the SIR model. I was wrong.
I thought it would be hard to top epidemiologists' dual use of R in the SIR model. I was wrong.
Ok, one last thing. Why can't this just be a "metaphor", used for expository purposes?
Here's our take:
Here's our take:
Further discussion (thread):
