By Kent R. Kroeger (Source: NuQum.com, June 11, 2020)
“More than a dozen states and Puerto Rico are recording their highest seven-day average of new cases since the pandemic began, hospitalizations in at least nine states have been on the rise since Memorial Day,” says The Washington Post. “In Texas, North and South Carolina, California, Oregon, Arkansas, Mississippi, Utah and Arizona, there are an increasing number of patients under supervised care since the holiday weekend because of covid-19 infections.”
“While the recent mass protests could exacerbate its spread, the incubation period of the (corona)virus means this latest rise in cases can more likely be traced to a loosening of lockdown restrictions around Memorial Day weekend late last month,” writes The Guardian’s Tim Walker.
Given the evidence — both in terms of new cases and hospitalizations — its an easy conclusion to draw.
Unfortunately, most news accounts of the recent rise of coronavirus cases in some (mostly southern) U.S. states misses the bigger story.
According to the following analysis of Johns Hopkins University Center for Systems Science and Engineering’s daily coronavirus data, the recent rise in coronavirus cases is connected more to the opening of warm, sunny beaches along America’s coastlines — particularly the Atlantic and Gulf Coast beaches where those states are also among the earliest to loosen lockdown restrictions (see Figure 1). But the increase is also evident in California where beaches were opened for the Memorial Day weekend, despite the state maintaining its general statewide lockdown.
Figure 1: New COVID-19 cases in U.S. Coastal States (7-day moving average)
In terms of sheer numbers, California, Florida and Texas have experienced the largest increases in daily new COVID-19 cases since the Memorial Day weekend (May 23–25). As of June 9th, California’s 7-day moving average of new cases each day is around 2,750 — its highest levels ever.
Likewise, Texas is at an all-time high at around 1,500 new cases each day (7-day moving average) and Florida is near its all-time high at 1,250 per day (7-day moving average).
However, a serious question remains as to precisely why these states (including other states such as North Carolina and South Carolina) are witnessing new highs but not others.
The easy suspect is the loosening of lockdown policies across the country, especially in Southern states where the summer vacation season is in full-swing.
Ballotpedia offers a summary of the lockdown policies for all 50 states (plus D.C.). Using their data, combined with the John Hopkins coronavirus data, I break out the 7-day moving average trends in new coronavirus cases for states in each of three lockdown categories: (1) states that continue to have a statewide lockdown in place, (2) states that began to loosen their lockdown policies after the start of the Memorial Day weekend (May 23 to 25), and (3) states that began to loosen lockdown restrictions before the Memorial Day weekend.
Figure 2 shows the trends for all three lockdown categories.
Figure 2: Comparing New COVID-19 cases by Lockdown Categories (7-day moving average)
Data source: Johns Hopkins University (CSSE); Graph by Kent R. Kroeger (NuQum.com)
Looking at the total U.S. trend in Figure 1, there has been a clear downward movement in new coronavirus cases since the first week of April. However, there is a small upward bump occurring soon after the Memorial Day weekend and before any possible impact by the George Floyd/Black Lives Matter protests, which began on May 26th (in Minneapolis) and increased steadily across the country through the first week of June.
That is evidence of a modest Memorial Day effect.
[Note: A large spike of 5,500 new coronavirus cases in Michigan on June 5th appears to be the function of a backlog in test results and not an actual spike in new cases in and around that day. Removing this spike does not significantly change the nominal shape of the U.S. totals in Figure 1.]
More interesting than the total U.S. trends, however, are the changes for the three lockdown categories.
For the six states that have not significantly loosened their lockdowns (California, Kentucky, New Hampshire, New Mexico, New York and Oregon), the trend in new cases has been consistently downward since early April — though, this encouraging trend has plateaued since mid-May.
For the 10 states that began opening up for normal business after May 23rd (Delaware, Hawaii, Illinois, Maine, Michigan, New Jersey, Pennsylvania, Rhode Island, Virginia and Washington), the downward trend in new cases did not begin until early May, but has continued consistently since.
Finally, those 27 states that began easing restrictions before May 23rd, the evidence is mixed. On one hand, there has been no sustained rend up or down in new COVID-19 cases since early April. However, these states appear to be the drivers behind the U.S. total uptick in new COVID-19 cases after Memorial Day, suggesting some of the states in this group are the likely culprits behind the national increase.
But what states and why?
Figure 3 breaks out the 50 states (and D.C.) by whether or not they are Coastal states within the warmer half of the country (i.e., states entirely or partially below 40° latitude; shown in Figure 1).
We have found the malefactors responsible for recent increases in coronavirus cases and it is not based solely on a state having loosened their lockdown restrictions. There are states that loosened their lockdowns before May 23rd and yet have not experienced a significant rise in COVID-19 cases (Connecticut, Idaho, Indiana, Iowa, Kansas, Louisiana, Missouri, North Dakota, Nebraska, Ohio, South Dakota, and Wyoming).
Something else is driving up coronavirus cases and I believe Figure 3 has found the prime suspect: warm, sunny beaches where documentary evidence has shown in the past few weeks that beach goers are not routinely practicing sound social distancing methods (e.g., facial masks and 6-ft personal spaces).
Figure 3: Comparing New COVID-19 cases in U.S. Overall and Coastal States (7-day moving average)
Data source: Johns Hopkins University (CSSE); Graph by Kent R. Kroeger (NuQum.com)
The New York Times interviewed Memorial Day weekend vacationers in Ocean City, Maryland who said very few people practicing proper social distancing methods.
“We expected 50/50,” said one Ocean City, MD beach visitor about the prevalence of facial masks during the Memorial Day weekend. “But this is like 10 percent, maybe.”
Similar accounts have been reported on beaches throughout the country since the first warm days of April.
As seen in Figure 3, Coastal states (which include California, Florida, North Carolina, South Carolina and Texas) have seen their COVID-19 cases rise persistently since mid-April — the peak of the spring break beach crowds and the start of the regular vacation season.
There are exceptions to this rule: (1) Lousiana has not seen a large rise in new cases (but neither is Louisiana a prime beach location), (2) New Jersey (where I live) saw its beaches begin to fill in late May and, yet, has not witnessed a surge in new COVID-19 cases, and (3) Arizona — which has experienced a large increase in new COVID-19 cases since Memorial Day — has no apparent ocean beaches.
Yet, the data is showing a strong connection between warm Coastal beach states and the recent spike in new COVID-19 cases.
Far more people will go to the beach this weekend than march in protests. In a typical year, 64 percent of Americans spend at least one summer weekend away from home and the most frequent destination is a beach (or about 13 million people during each of the summer weekends). From 2016 to 2018, only one-in-five Americans participated in at least one protest — a time period which includes the Women’s Marches around Donald Trump’s inauguration — and the recent mass protests for George Floyd and Black Lives Matter (BLM), while likely larger and more widespread, probably has not exceed 10 million in total (based on my analysis of the recent BLM marches listed here).
None of the findings here suggests mass protests can’t spread the coronavirus or that states where lockdown restrictions have loosened too fast or recklessly won’t experience a spike in new cases. Both are likely sources of some of the newest COVID-19 cases.
Still, the evidence is stronger that recent increases of COVID-19 in the U.S. are a function of the specific social distancing behaviors of Americans (or lack thereof) when they are relaxing along our nation’s many warm beaches.
To anyone I might see on one of the New Jersey beaches this weekend: Please wear masks and keep your distance from me and my family. No offense intended.
The dataset and statistical code used for this analysis can be requested at: firstname.lastname@example.org