President Donald Trump tells a lot of outlandish lies. Sometimes, though, he employs a more sophisticated form of political dishonesty: using an accurate statistic in a deceptive way.
At his coronavirus briefing on Wednesday, Trump continued to try to paint a picture of national progress. One of the things he cited as evidence was what he framed as a big decline in the test positivity rate — the percentage of people who have tested positive versus the total number of people who have been tested.
“Our nationwide positive test rate is beginning to decline and is currently at 8.8%, compared to over 16% at its peak in April. It’s coming down. It’s coming down fairly rapidly,” he said.
Facts First: The national positivity rate is not rapidly declining. While Trump was correct that the rate is now much lower than it was in April, he didn’t mention that it is also much higher than it was in May and June. In fact, the current rate is about double the rate at its lowest point in June.
The positivity rate is seen as a critical indicator of the state of an outbreak. It helps show whether an increase in cases is simply the result of more tests being conducted or whether there is a truly worsening problem.
The national positivity rate was well over 16% (all figures in this article are seven-day averages) at various points in March and April, when testing capacity was much more limited, according to data provided by the COVID Tracking Project and published by Johns Hopkins University.
By mid-June, when testing had expanded significantly, the positivity rate fell to a low of 4.3%. But then, as major outbreaks erupted in states like Florida, Texas, Arizona and California, the national positivity rate steadily increased, up to a high of 8.7% on July 12, 13 and 14.
Since then, the national rate has been essentially flat — declining only very slightly to 8.5% on the day Trump spoke.
While we don’t yet know if that slight decline is a blip or the start of a trend, there is at least some basis for Trump’s initial claim that the rate is “beginning to decline.” But there is not evidence for his claim that “it’s coming down fairly rapidly.”
“No, there has not been a rapid decline in percent positivity nationally during July. While some regions have been improving, others are not,” said Jennifer Horney, professor and founding director of the epidemiology program at the University of Delaware.
Horney said it is important to note that using national figures like these can obscure important local and state data about outbreaks in particular places. For example, Arizona’s positivity rate during its July crisis has regularly exceeded 20%.
According to the COVID Tracking Project, the positivity rate in the Northeast region was just 1.9% as of the day Trump spoke here, a major decline from 6.9% two months prior. Conversely, the rate in the South was 12.6% on the day Trump spoke, a major increase from 5.4% two months prior.
The country as a whole is now far above the less-than-5% target level the World Health Organization says should be reached, among other targets, before pandemic restrictions are relaxed.