Yes, the COVID-19 Trendline Looks Exponential

John Butcher, publisher of Cranky’s Blog, has turned his attention from K-12 education to the COVID-19 virus. In scrutinizing yesterday’s data in the previous post, I asked if the spread of the WuFlu was decelerating. He has answered the call, submitting the graph above, which I shall interpret for you in a moment.

We’re not getting any such analysis from the Northam administration. Indeed, in a press conference today, Dr. Lilian Peake, chief epidemiologist on Governor Ralph Northam’s COVID-19 leadership team, acknowledged, “We don’t have a specific projection now. But we are working on a model, and so we hope to have more information about that later in the week.” (See the video, 28:30 minute mark.)

That’s an extraordinary admission — after all this time the administration has no model for forecasting the spread of the coronavirus! In other words, Northam is making decisions to close schools, shutter non-essential businesses, and otherwise throttle the life and economy of the state of Virginia based on … what? His gut instinct?

The Governor may not have an epidemiological model, but he does have access to the same data that we do (if not more), and, in Cranky’s reckoning, the epidemic is spreading at an exponential rate, which, one can argue, might justify his latest draconian decisions. And any blip, like the one I highlighted in my post earlier today, does not seem terribly significant. The chart above shows the increase on a logarithmic scale in the total number of WuFlu cases in Virginia. The next chart shows the increase in the number of new cases.

There’s a little more variability here, but the trendline is essentially the same. For an informed discussion of what these charts mean, don’t ask me. Leave a comment and ask John.

In the meantime, let’s hope that the people who really understand statistics get their act together in a hurry and finish building that epidemiological model for the Governor.


There are currently no comments highlighted.

14 responses to “Yes, the COVID-19 Trendline Looks Exponential

  1. I don’t think graphs mean much when you consider widespread testing is really just getting underway. We expected the number of new cases to rise sharply as testing became more available. But beyond that, people who are testing positive now were presumably infected as much as two weeks ago. So isn’t is possible that through social distancing, etc., the curve has started to flatten but we just can’t tell because we can’t make good comparisons from early in the month?

  2. Given people’s skepticism of modelling data these days, not sure there is a win-win for Northam in doing so – the critics are going to pounce if they disagree.

    But all the science is saying with unanimity – it’s going to expand massively it has already done overseas – we just don’t know with certainty how far it has expanded in Virginia yet because we are not doing enough testing across the state to be able to discern that with any precision.

  3. In the email that shipped these to Jim, I wrote:

    “Your Excellency!

    “It’s still early days and the limited testing surely influences
    the numbers, but those numbers certainly look like an
    exponential growth.”

    Indeed, those numbers show a 3 day doubling period, and the R-squared of 99% suggests a remarkable fit.

    As to what all that means, the only firm conclusion is this:

    • Your Excellency:

      I endorse that only firm conclusion.


      The armed robbery of the US treasury by the leftists continues this very morning in the National Capital Building in Wash, DC.

  4. Through another aspect of my life I’d become aware that Virginia’s Department of Health is very, very weak. This is a long standing issue. That weakness is now on full display. Something else for the after-action studies, what the shipyard guys called the “hot wash.” (Loved that industrial colloquialism.)

    • “Virginia’s Department of Health is very, very weak. This is a long standing issue.”

      Likely “Virginia’s Department of Health is very, very weak,” by intention. Some Virginia politicians have an odd habit of selling portions of their state and its citizens and their heritage to the highest bidders. So cash money, anybody’s money, from anywhere too often rules all else in Virginia, even history.

      Here recall the Speaker’s Fund, how money donation into those coffers are closely tied to Virginia’ approval of gambling casino licenses to donors.

      Recall too the attempted sale of the Bull Run Battlefield to Disney, all of it covert of course, but in practical effect it was a sale, a way to line pockets of powerful Virginians with Disney money.

      Same with UVA 10 days ago, when the caronavirus was ramping up big time. What was UVA president Jim Ryan’s response? He sent out a plea letter to all alumni, send me more money. Oddly, he never once raised looming crisis that at that very moment consumed the nation.

      Why? And for what did Ryan want more money?

      After all, at that very moment, the Alumni getting Ryan’s plea for more of their own money, those same alumni were watching their jobs, their income, their businesses and its income, their retirement savings, their livelihoods and future, and their family’s future and their nation’s future, all this was ever more gravely threatened from all sides, then and there evaporating, dissipating, and going down the toilet, in a financial collapse not seen since the Great Depression of the 1930s. And President Ryan, and UVA want more of our money.


      Here is Ryan answer: “to serve … to prepare our students to lead in an increasingly diverse and globally connected world … to enable all our undergraduates to have at least one international experience, to create more pathways for our students to engage in public service, to help them take better advantage of this diverse and inclusive community by allowing 2nd year students to live on the Grounds … Please Give Today. ”

      Notice the strong implication of Ryan’s plea for more of our money in our own fraught times.

      That by Ryan’s standards, teaching your kids to work, live and thrive in America’s private sector is not worthy and up to the standards of UVA.

      That by Ryan’s and UVA’s standards, teaching your kids to work, learn, earn, and thrive in America to protect their parents and themselves and their community and America, and in so doing to learn to work and build their own new families, your grandchildren, in their own local American community is not worthy of UVA and President Ryan’s Standards. Nor is any of it worthy of your own money as UVA intends to spend it. So Ryan’s never mentions this, like he never mentions the plague that is as expected now killing people all around us, threatening America’s future.

      Why? Because you, your kids, your life, your community, and your country at not inclusive and diverse according to the diktats of Ryan and UVA. So now worthy of mention even.

      Do you wonder whether, when writing his plea that you give him more of your money in this time of a great plague, Ryan ever considered what was going on right then in America. How his donors and students lives and livelihoods were threatened that very day with possible desolation and collapse, at the very moment that he penned the his plea letter’s final words. “P.S Honor the future today with a gift to the University of Virginia.”

      We’ll never know the answer to this question. But there is a telling hint. His letter I received around March 13th is UNDATED, save for word SPRING.

  5. First, don’t look at daily rates – too noisy. Pick a number of cases, say 10,000 and watch the number of days it takes to achieve the next 10,000. What you’ll see with exponential growth is fewer and fewer days to meet the number, e.g., 10 days for the first 10, 8 for the next 10, 6 for the next, etc.

    But, correct me if I misunderstood, are you saying that the Gub’na screwed up by not modeling the infection rate specific to Va.? That’s a bit provincial, isn’t it? Should we be modeling the CO2 rise only over Va. before considering climate questions?

    • Yes. That’s what it sounded like. Why is graphing this stuff so important anyhow if we know that it looks pretty much the same in a lot of places – and is expected to be that way where there is enough sampling done and in places where sampling and reporting is not as good, the graphs won’t even be really that useful.

      Or is there still doubt with respect to the disease actually expanding exponentially – as predicted?

    • “Are you saying that the Gub’na screwed up by not modeling the infection rate specific to Va.?”

      Here’s what I’m saying: The governor’s staff says it is working on a model, but it’s not ready yet. If the governor thinks it’s important enough to develop a model, he presumably thinks it would be helpful in making decisions. Whether the model is Virginia-specific or not, I don’t know. But I would say this: If it’s important to have an epidemiological model, one would think it would have been a top priority to develop. Also, we can conclude that the governor is making drastic decisions affecting the economy and peoples’ livelihoods without benefit of a model.

      • re: ” Also, we can conclude that the governor is making drastic decisions affecting the economy and peoples’ livelihoods without benefit of a model.”


        might want to re-word…

  6. How dare you criticize the governor. It sickens me!

  7. Indeed, looks a bit scary to me. But just one observation. John Butcher is the expert in this area. And my HS or college math is long behind me, but I think I got this right. If Butcher wants to underscore and demonstrate an exponential rate, why plot on a logarithmic scale. One has to have a deep mathematical understanding to know log scales. At first glance, the chart is a straight slope – ie. not exponential. Only upon further inspection, did I see the log scale….and that is reason for concern.

    • I don’t care about the slope. Wake me when it flattens out, and open the bubbly when it starts to decline. Me, I’m now betting that’s still 60 days off.

Leave a Reply