NYTimes March 13th, 2020
On Tuesday, they noticed a tweet by Mike Baker of The New York Times, in which he noted the cumulative number of coronavirus cases in the U.S. by date:
- Jan. 14 — 0
- Jan. 21 — 1
- Jan. 28 — 5
- Feb. 4 — 11
- Feb. 11 — 14
- Feb. 18 — 25
- Feb. 25 — 59
- Mar. 3 — 125
- Mar. 10 — 1,004
“That is exponential growth,” Dr. Nick Jewell said. (He noted that the latest increase was also likely a reflection of increased testing.)
“The graph that really grabbed my attention was the one showing a model of daily new cases of Covid-19 with social-distancing measures starting just one day apart,” Dr. Britta Jewell said. “It only takes a one-day difference in action to see a 40 percent reduction in cases — that’s enormous. It really conveys the urgency of the situation.”
The graph illustrates the results of a thought experiment. It assumes constant 30 percent growth throughout the next month in an epidemic like the one in the U.S. right now, and compares the results of stopping one infection today — by actions such as shifting to online classes, canceling of large events and imposing travel restrictions — versus taking the same action one week from today
Conclusion
The difference is stark. If you act today, you will have averted four times as many infections in the next month: roughly 2,400 averted infections, versus just 600 if you wait one week. That’s the power of averting just one infection, and obviously we would like to avert more than one.