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| Italy's lockdown. |
April 3, 2020—On a Zoom chat this morning, someone asked about the future for the U.S. and New York City economy. I suggested that it depends on how we manage the pandemic at the NY City, State and Federal level.
The number to watch, I said, is the death rate, because by now everyone is aware that the "confirmed cases" number is dependent on how many tests are done. Shortages of testing kits reduce the number of confirmed cases but also, by delaying proper care and isolation, contribute to higher death rates. The number of cases is not a good measure of the outcome of the disease.
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Chart 1. Virus Cases by Country, David
Leonhardt, NY Times, March 31, 2020. |
Whichever measure we use, the prognosis for the United States is for the disease to worsen before it gets better.
Let's look first at the number of cases. Did the United States get ahead of the curve between the time that the disease started in China and then spread to Italy?
The chart at right, by David Leonhardt in the
NY Times on March 31, suggests not.
In fact, by this point in the progress of the virus, China and Italy and even Spain were both doing better based on cases. But this chart is subject to testing bias. If the United States is "not flattening," the reason may simply be that the United States has stepped up the rate of testing.
Deaths in a democratic country are hard to fake or hide. People are paid to track them. A death from the coronavirus follows a gruesome pattern that should now be not hard to diagnose. Population numbers are closely watched. So, horrible though they are, the death rates are "good" measures of the spread of COVID-19.
The table at right shows the top seven lines of a table published as an Upshot in the
New York Times. As the accompanying text in the story points out, the death rates lag cases, so they are not the best measure of the challenges being faced at the moment in the hospitals.
Because China was ahead of Europe, and Europe has been ahead of the United States, in facing the coronavirus, the Lombardy and Wuhan death rates are worth looking at as a guide to what might happen in the New York City area.
If there is a bias in the death rates in Lombardy and Wuhan, it is probably on the low side:
- Yes, Italy has an unusually elderly population, second in the world after Japan. This would tend to raise the death rates relative to New York — the median age in Lombardy is about 45, whereas it is 38 in New York. But Lombardy numbers may be considerably understated because many deaths that did not occur in hospitals were not counted by the health care reporting system — i.e., they might not have been counted if they occurred where people live, even if they were in nursing homes.
- The Wuhan numbers may also be undercounted. A classified U.S. report suggests that C.I.A. insiders believe that Chinese cases and deaths from the virus may have been systematically underreported.
What do the death-rate numbers tell us? It is not in the Upshot story, but if the progress of the disease in the New York area matches that of Lombardy, we can expect a death rate of approximately 0.5 per thousand applied to a New York City metro area population of 20 million, or
10,000 deaths.
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Chart 2. New York deaths higher than
Lombardy at same point. Upshot,
NY Times, April 3, 2020. |
The math is not hard to follow. Lombardy suffered 5,000 deaths, in round numbers. It has half the 20 million population of the
New York City Metro Statistical Area.* So one would expect, all else equal, that the New York metro area would end up with double the Lombardy deaths, or 10,000.
Today, April 3, the
New York Times published another Upshot chart showing how we are doing on death rates relative to the Lombardy region. It should not make us complacent.
Upshot shows on the chart that the NY City death rate until the last observation has been
doubling every two and a half days. It has been on a trajectory well above Lombardy's for a week, until the latest day. Governor Cuomo has noted in his 11 a.m. daily updates a marked improvement in the State trajectory in the last few days. If he is right, it is a breakthrough and he should get credit for it. The Governor's recent moves have improved the odds that the State's hospital system will be able to handle the coming peak load of patients. Meanwhile, we should watch the numbers carefully. It still seems likely that the New York metro area will exceed Lombardy's death rate.
* The NY metro is the statistical area (MSA), not the Combined Statistical Area (CSA), which would add another 3 million people. The NY MSA is composed of four Metropolitan Divisions; one of them is Nassau-Suffolk, two counties that together constitute Long Island as a Metropolitan Division.
