The 3DDRR held steady at 1.26
I think a lot of people have been waiting for the rest of the country to look like New York. At this point, it does not look like that is going to happen. I will speculate more on this tomorrow. As usual you can see the data on this spreadsheet.
Untrustworthy numbers. I worry that because of Easter we are seeing a lag in reporting of deaths, which will show up on Monday or Tuesday. But for what it’s worth the overall 3DDRR and the 3DDRRxNY were both at 1.34 today. For historical data on 3DDRR, see Aaron Lindsey’s spreadsheet.
As Nate Silver says, case counts are meaningless. He goes into the weeds of how testing protocols affect reported cases. I say don’t bother.
I want to try to infer the number of people who have been infected from the number of deaths. I assume that death reports in the U.S. are a more reliable indicator of what is going on here. Call the number of deaths D. The problem is that we don’t know three things:
–the number of deaths per 1000 people that have been infected. r. So if the death rate (relative to the true number of people that have been infected, which is not at all the same as the number of reported cases) is 2 percent, then r = 20.
–the typical number of days between infection and death. Call this n.
–the growth rate of the number of infections from n days ago until now. Call this g(n). Because the 3DDRR stayed at 2 for a long time, I was estimating g(n) as 2^(n/3).
The algorithm to estimate the number of people who have been infected today is D*g(n)*1000/r. If the number of days between infection and death is 9, then n = 9. If g(n) = 2^(n/3), then g(n) = 8. So if r = 20, then the estimate of the number of people who have been infected today is 400 times the number of deaths as of today. For New York state, that would mean about 1.64 million people infected. If instead we assume that n=15 and r = 2 (o.2 percent of infected people die), that says that 64 million New Yorkers have been infected–clearly an over-estimate. Either r is greater than 2 or g(n) is less than 32, or both. g(n) could be less than 32 even though n is 15, provided that the the growth rate of infections per day started to drop in recent days, which would mean that the 3DDRR is going to drop soon. In fact, I’m inclined to expect a pretty dramatic drop in 3DDRR for New York in the coming days.
Two reasons to do this.
1. I messed up the arithmetic the first time. Now corrected.
2. Let’s check this approach against New York information. New York is at 4159 deaths. Lower bound estimate for cases would be 4159 times 50 times 8 = 1.64 million cases. Upper bound estimate would be 4159 times 500 times 32 = 64 million cases, which is more than the population of the state. So I think we can rule that out. Probably because the true case fatality rate is significantly higher than 0.2 percent. If you believe that the case fatality rate is that low, then I think you have to believe that the number of cases stopped doubling every three days in NY at least a week ago, which is another plausible scenario.
Please check my arithmetic!
at 6:30 pm eastern time today, March 31. Meeting id 824-584-0623.
It will be a learning experience.
[UPDATE: I really got a lot out of it! I think that there is a real appetite for something with an alternative point of view. But I decided that I need to think more carefully about structure. The trick will be to balance the advantages of a central focus with the fact that many people have something to contribute.
I am going to take what I learned from this and brainstorm with some other like-minded folks and then come back with another iteration, hopefully soon.
Other comments welcome.]
Note: I’m done with posting on the virus crisis. All I can do at this point is express my anger, and that is not going to accomplish anything. I have some posts that I wrote a month ago that I’ve been saving up. Here is one of them.
I do a post on this every year. Some thoughts on this year: Continue reading
Some arguments against the masks and gloves approach:
1. Not enough masks. But meanwhile, you can tie a scarf around your mouth and nose. No, it doesn’t filter out everything. But it could filter out enough. Then go home and wash the scarf. The point is to reduce my ability to spread the virus to you, in case I have it without knowing it. At lower cost than shutting down lots of businesses.
2. You can still get the virus from doorknobs. Maybe this is true–we still have not done the experiment. If it is true, then we can try to mitigate it using handwashing, being careful how we touch things, and using disinfectant. No, that won’t be perfect, but again the goal is reduction of spread, not total elimination.
3. People might become overconfident, thinking that scarves confer immunity. Probably true for *some* people, but I would hope that if the approach is clearly communicated, most people would continue taking other precautions. But they would feel less nervous about going to stores or getting their hair cut.
Look, people, our current approach looks like stupidity layered on stupidity. Because we don’t have a clear picture of prevalence or how it spreads, we are advising people to stay away from one another. Because staying away from one another cripples business, the stock market has plunged, the Fed is taking over more of the financial market, and Congress is wrangling over a $1.5 trillion “stimulus,” i.e., trough for special interests to feed at. And we are witnessing President Trump get into a battle royale with his health advisers. Is this what you want?
Given all of the issues involved, the optimum spread rate for the virus from a policy perspective isn’t going to be zero. If we can just come up with an alternative that allows people to mingle in public while keeping the spread rate low enough to avoid another Italy or NYC, that is good enough, in my opinion. I am looking for ways to keep our hospitals from becoming overwhelmed that don’t involve so much economic dislocation.
Scarves now, masks when they’re ready. I would like to thank commenter Handle for the scarves suggestion.