Gordon L. Weil
People are fascinated by numbers.
Not surprisingly, the Covid-19 pandemic
has become entangled with statistics. The problem may be that people
focus on those numbers, so they lose sight of the real problem.
How many cases have there been in China
or Italy or the U.S.? Where is the pandemic “epicenter” based on
the case count? What's the number of ventilators, face masks, or
protective gear?
Experts have been busy building models
to create forecasts of the possible number of new cases, recoveries
and deaths. Daily press briefings are mainly about the latest counts
and the expected shortfalls in equipment generated by models. Models
seem to be used to frighten people.
Suddenly, we are expected to understand
enough math to know that an important goal is to “flatten the
curve.” The models produce a curve. What curve? What does
flattening do? Whatever, let's just do it.
New York Gov. Andrew Cuomo heroically
fights the country's toughest challenge, but he seems to believe he
can scare people into reducing the spread by citing forecasts. In
Washington, the federal government publicly revealed a controversial
forecast showing a stunning quarter of a million dead.
Dr. Nirav Shah, the Maine CDC head,
says he uses the models not to produce forecasts as their main
purpose, but to plan for a range of possible health challenges. He
understands that the models tell him that what might happen depends
on what people do to reduce the spread.
That's why he reluctantly released
model results. People are likely to believe models yield reliable
forecasts, when they are really only a tool.
The most important data from a Covid-19
model is how many cases can be expected. Differing assumptions about
people's behavior produce a wide range of results, but no single,
reliable forecast. People influence the model not the other way
around.
Social distancing, using face masks and
hand washing matter more than models.
The simple lesson of the models is that
more spread means more illness. That hardly requires a lot of detail
about the numbers. And knowing the exact number of people who will
be affected is impossible.
Shah makes one mistake when he says the Covid-19 forecasts are like
weather forecasts. Weather forecasts are famously inaccurate, because
conditions beyond our control continually change. But people can
control Covid-19 models by cutting down on current cases. In fact,
right now, that's about all that can.
People would be unwise to take comfort
from models or even from the belief that “flattening of the curve”
is the goal. We simply know too little and numbers produced by
models may tempt people to believe their hopes.
Flattening the curve does not
necessarily mean that fewer people will get Covid-19. It means that
the number will be spread over a longer period, which will stress
hospitals less and provide time to find a helpful medication or
vaccine. That could save some lives.
“It's not over, until it's over,”
said Yogi Berra, the philosopher-baseball player.
With stay-at-home orders to fight the
spread, the economy loses both producers and consumers. It slows
down. The government keeps it alive by pouring out money to people
and companies.
President Trump and others see the
stock market as an indicator of the health of the economy.
Investors have extreme reactions to each day's model numbers and data
reports, which they treat as a daily forecast. The market swings
wildly.
Trump's re-election is reportedly
dependent on the state of the economy. Like everybody else for their
own reasons, he wishes for a speedy economic recovery.
Falling stock market indexes –
numbers, again – cause some policy makers to press for an early
finding that there is a cure for the virus and that the crisis is
ending, freeing people from protecting themselves so they can get
back to work.
Peter Navarro, a presidential advisor,
says his economics doctorate makes him as much an expert on the virus
models as the medical doctors. He asserts the crisis is not so bad
as they say, so we should test and simply declare, “It's over.”
He admits that some people will die. Economic recovery is apparently
worth lives.
“Dr.” Rudy Giuliani, Trump's
personal lawyer, claims that some sketchy data is enough to show an
unproven drug is the Covid-19 cure, though scientists are still far
from that conclusion. Fall ill, take the drug, and go back to work.
Navarro is flat wrong. Giuliani is
dangerous. The health of the economy depends on the health of
people.
The health of people depends on their
protecting themselves and others and, in the end, on science, not
math.