I just did an updated calculation of what happens to America if we do nothing. And it is nothing short of terrifying.
The current rate of spread is a near-perfect exponential. If we do not change our behavior dramatically and fast, here is what the math says: 1/n
The current rate of spread is a near-perfect exponential. If we do not change our behavior dramatically and fast, here is what the math says: 1/n
The last eleven days give a remarkably good fit for linear regression on the log cases (R^2=0.9981), that's good enough to project the exponential. Here's what happens:
~March 18th the US passes 10k cases
~March 26th we pass 100k cases
~April 4th the US passes 1 million cases
~March 18th the US passes 10k cases
~March 26th we pass 100k cases
~April 4th the US passes 1 million cases
If 10% require hospitalization:
~April 5th the US passes 1.6M cases, or 10x the number of ventilators
~April 11th we 9.24M cases, or 10x the total hospital beds
If we do not change our behavior, by early April the entire US medical system will be treating critical Covid-19 cases
~April 5th the US passes 1.6M cases, or 10x the number of ventilators
~April 11th we 9.24M cases, or 10x the total hospital beds
If we do not change our behavior, by early April the entire US medical system will be treating critical Covid-19 cases
Even if these numbers are off by a factor of 2 or 3, it only changes by one or two days when it happens. But this future is not set in stone. With only ~3,000 cases in the US, there is still time to act, but we have to radically change our behaviors, and we have to do it now.
Close everything. Work from home and isolate to the maximum extent possible. Do not go to bars, avoid all groups. And, and this is really important: encourage others to do the same. Contact your elected officials and urge them to shut things down now, before it's too late.
It is going to be hard, and it will be costly, but the actions already over the last few days have given me hope. Stay strong, keep it up, and encourage others to do the same.
Update: there are many valid critiques of the details of this estimate, but none change the conclusions.
-It's just a line fit: true, it should be a sigmoid, but for <1% of the population infected, exponential is valid approximation, and certainly within measurement error.
-It's just a line fit: true, it should be a sigmoid, but for <1% of the population infected, exponential is valid approximation, and certainly within measurement error.
-We are undertesting: indeed, but we're likely not undertesting hospitalized cases by as much. So the total growth of severe cases will be similar.
-There's a lot of uncertainty in percent severity: see previous point.
-There's a lot of uncertainty in percent severity: see previous point.
-I am regressing on levels: Good catch, I made a mistake, the R^2 is overinflated. The qualitative predictions still hold, though perhaps the days on which things happen are wrong by a couple in either direction.
Obviously an unfettered exponential is an approximation (otherwise more than the whole world would be infected soon), but up until a surprisingly late point it’s a good approximation for many types of biological growth including epidemics
