[aaron695]

< As it grows, its rate of growth will increase

No, R will stay the same. Or decrease as the population becomes more exposed.

[wcoenen]

He's taking about the number of people infected per unit of time, which will indeed increase over time if the reproductive number stays larger than 1.

[biot]

Growth is number of people per unit time. Rate of growth is number of people per unit time squared. Just as with speed vs. acceleration, there certainly is a distinction.

[wcoenen]

I'm not a native speaker so I could be wrong. But in the wikipedia article about exponential growth, "growth rate" is defined as the first derivative with respect to time, which contradicts what you are saying: https://en.wikipedia.org/wiki/Exponential_growth#Differentia...

I understand the distinction you are trying to make, but I think what you call "growth rate" would actually be "growth acceleration".

[gbrown]

Actually R0 is a measure which captures both population mixing activity and the infectiousness of the pathogen - the two processes are confounded. That means that it varies a lot over space and time.