Which States Are Fighting COVID-19 Most Effectively?

Do we really need to shut down restaurants? Or is this a countermeasure with low value at fighting COVID-19?Kevin Drum

Fight disinformation: Sign up for the free Mother Jones Daily newsletter and follow the news that matters.

Reader SL forwarded to me an interesting estimate of how well each state is doing controlling the spread of COVID-19. I’m a little reluctant to write about this since I can’t independently judge it, but it’s a weekend, so let’s go wild.

The author is Kevin Systrom and he uses Bayesian statistics to estimate the trend value of R0 which tells us how fast the virus is spreading. Any value above 1.0 means that each infected person infects more than one other person. In that case, the total number of infections rises exponentially. A value below 1.0 means each infected person infects less than one person. In that case, the total number of infections will decline. Obviously our goal is to put in place countermeasures that will get the value of R0 below 1.0 and keep it there.

I’ve long been sort of fascinated by Bayesian statistics, even though it seems like it mostly produces the same results as ordinary frequentist statistics. But that’s OK: it means that the procedure outlined in “Real Time Bayesian Estimation of the Epidemic Potential of Emerging Infectious Diseases”—which Systrom applies to COVID-19—is probably fairly conventional. The real problem isn’t with the statistical methodology, but with the fact that Systrom relies on confirmed case counts, which we know to be highly unreliable. On the other hand, the algorithm compares case counts day-to-day over a period of seven days, and it’s likely that any errors in the count stay about the same over such a short period. So there’s reason to think that this approach might produce something useful.

Without further ado, here are his results:

(Note that these results only go through April 11. It would be interesting indeed to see an updated chart.)

The bars show the point estimate for each state: Idaho is lowest at R0 = 0.55 and Rhode Island is highest at R0 = 1.55. However, the states are arranged by the high point of their error bars. The reason for this is that the size of the error bars varies widely, and unless the top of the error bar is below zero you can’t be sure that R0 is truly below 1.0. Systrom suggests that if the top of the error bar is below 1.1, it means a state most likely has the epidemic “under control.” There are eight states in this category:

  • Louisiana
  • Idaho
  • Washington
  • Michigan
  • New Jersey
  • Florida
  • California
  • New York

The states that are worst off are the ones where even the bottom of the error bar is above 1.0. There’s not a remote chance that they’re anywhere near getting things under control. There are 12 states in this category:

  • Alabama
  • Virginia
  • Illinois
  • Kentucky
  • South Dakota
  • Pennsylvania
  • Connecticut
  • Texas
  • Georgia
  • Massachusetts
  • Maryland
  • Rhode Island

Systrom adds this: “It’s clear that all non-lockdown states cluster on the right-hand side. While we cannot be sure the true Rt value is that high, this graph should give any policymaker in a non-lockdown state pause.” (The non-lockdown states are the red bars in the chart above.)

Systrom takes this as evidence in favor of lockdowns, but I have a different interpretation. Take California, which is the poster child for taking COVID-19 seriously. We locked down early and tight and Systrom puts our R0 at about 1.0. Meanwhile, South Dakota is the poster child for its governor’s refusal to even think about lockdowns and Systrom puts their R0 at 1.5.

Think about that. There are differences between states, of course, and that might account for part of what’s going on. Still, an enormous disparity in countermeasures produced a difference in R0 of only 1.0 vs. 1.5. That doesn’t seem like an awful lot. FWIW, I take it as yet another piece of data that we’re locking down without knowing which measures really work and which are window dressing. There’s just too much evidence accumulating that the value of (some) countermeasures is simply not as great as we’ve been assuming.

AN IMPORTANT UPDATE

We’re falling behind our online fundraising goals and we can’t sustain coming up short on donations month after month. Perhaps you’ve heard? It is impossibly hard in the news business right now, with layoffs intensifying and fancy new startups and funding going kaput.

The crisis facing journalism and democracy isn’t going away anytime soon. And neither is Mother Jones, our readers, or our unique way of doing in-depth reporting that exists to bring about change.

Which is exactly why, despite the challenges we face, we just took a big gulp and joined forces with the Center for Investigative Reporting, a team of ace journalists who create the amazing podcast and public radio show Reveal.

If you can part with even just a few bucks, please help us pick up the pace of donations. We simply can’t afford to keep falling behind on our fundraising targets month after month.

Editor-in-Chief Clara Jeffery said it well to our team recently, and that team 100 percent includes readers like you who make it all possible: “This is a year to prove that we can pull off this merger, grow our audiences and impact, attract more funding and keep growing. More broadly, it’s a year when the very future of both journalism and democracy is on the line. We have to go for every important story, every reader/listener/viewer, and leave it all on the field. I’m very proud of all the hard work that’s gotten us to this moment, and confident that we can meet it.”

Let’s do this. If you can right now, please support Mother Jones and investigative journalism with an urgently needed donation today.

payment methods

AN IMPORTANT UPDATE

We’re falling behind our online fundraising goals and we can’t sustain coming up short on donations month after month. Perhaps you’ve heard? It is impossibly hard in the news business right now, with layoffs intensifying and fancy new startups and funding going kaput.

The crisis facing journalism and democracy isn’t going away anytime soon. And neither is Mother Jones, our readers, or our unique way of doing in-depth reporting that exists to bring about change.

Which is exactly why, despite the challenges we face, we just took a big gulp and joined forces with the Center for Investigative Reporting, a team of ace journalists who create the amazing podcast and public radio show Reveal.

If you can part with even just a few bucks, please help us pick up the pace of donations. We simply can’t afford to keep falling behind on our fundraising targets month after month.

Editor-in-Chief Clara Jeffery said it well to our team recently, and that team 100 percent includes readers like you who make it all possible: “This is a year to prove that we can pull off this merger, grow our audiences and impact, attract more funding and keep growing. More broadly, it’s a year when the very future of both journalism and democracy is on the line. We have to go for every important story, every reader/listener/viewer, and leave it all on the field. I’m very proud of all the hard work that’s gotten us to this moment, and confident that we can meet it.”

Let’s do this. If you can right now, please support Mother Jones and investigative journalism with an urgently needed donation today.

payment methods

We Recommend

Latest

Sign up for our free newsletter

Subscribe to the Mother Jones Daily to have our top stories delivered directly to your inbox.

Get our award-winning magazine

Save big on a full year of investigations, ideas, and insights.

Subscribe

Support our journalism

Help Mother Jones' reporters dig deep with a tax-deductible donation.

Donate