Author Archives: Nuetzel

Trump’s Payroll Tax Ploy

15 Tuesday Sep 2020

Posted by in Fiscal policy, Taxes

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President Trump’s memorandum to Treasury Secretary Steve Mnuchin on payroll tax deferral is bad economic policy, but it might ultimately prove useful as a political weapon. The memo, released in August, instructed the Treasury to allow employers to suspend withholding of the employee’s share of FICA taxes (6.2%) until the end of the year, but it does not forgive the taxes. Only Congress (with the President’s signature) can eliminate the tax obligation. There are several reasons I don’t like it:

  1. Assuming the tax obligation is forgiven, it would provide some relief to those who are already employed (and earning less than $4,000 every two weeks), but not to the unemployed. Thus, as relief from coronavirus-induced job losses, this doesn’t cut it.
  2. It does not reduce the cost of hiring, as would a permanent reduction in the employer’s share, so it does not improve hiring incentives.
  3. The deferral creates uncertainty: will the tax bill be forgiven? If not, will the employee be on the hook? Or the employer? What if an employee leaves the company having received a deferral?
  4. The measure will not be an effective stimulus to spending. It is not an addition to workers’ permanent income since it is a temporary “holiday”. Income perceived as temporary adds little to consumer spending. And it doesn’t constitute a temporary tax break unless employers participate (see below), and even then only if Trump is re-elected and if Congress agrees to forgive the tax.
  5. Trump suggested that the tax will be forgiven if he is re-elected. It’s a rather unsavory proposition: create an immediate tax benefit paired with a matching future obligation with forgiveness contingent upon re-election!
  6. Long-term funding of Social Security is already problematic. Adding a payroll tax holiday on top of that, assuming the taxes are forgiven, only aggravates the situation. Yes, I can imagine various “long-game” reform proposals that might attempt to leverage such a break, but I consider that highly unlikely.

It’s no surprise that a number of large employers are not participating in the tax deferral. such as CVS, JP Morgan Chase, UPS, Home Depot, and Wells Fargo.

Small employers have an even bigger problem to the extent that they lack sophisticated accounting systems to handle such deferrals. Here’s Warren Meyers’ take on the payroll tax suspension:

“We have 400 employees today, but since we are a summer seasonal business we will have fewer than 100 in January. If there is a catch-up repayment in January (meaning Congress chooses not to forgive the taxes altogether), most of my employees who would need to repay the tax will be gone. Do you think the government is just going to say, ‘oh well, I guess we lost that money’? Hah! You don’t know how the government works with tax liens. My guess is that for every employee no longer on the payroll for whom back employment taxes need to be collected, the government is going to say our company is responsible for those payments instead. We could be out hundreds of thousands of extra dollars. President Biden will just say, ‘well I guess you should not have participated in a Trump program.’

So this is the vise we are in: Either we participate in the program, and risk paying a fortune in extra taxes at some future date, or we don’t participate, and have every employee screaming at us for deducting payroll taxes when President Trump told them they did not have to pay it anymore. And what happens if Congress does come along later and forgive the taxes, what kind of jerk am I for not allowing my employees to benefit from the tax break?

A payroll tax rollback was considered for the Republican stimulus packages that failed in Congress this summer, but that provision was said to be “negotiable”. In any case, nothing passed. Surely Trump’s economic advisors know that the economics of the payroll tax memo are lousy, even if Trump doesn’t get it.

I can’t decide whether the whole thing is Machiavellian or just a goof. Perhaps Trump is so eager to be seen as a tax cutter that he is willing to gloss over the distinction between a tax cut and a deferral. If the taxes owed are not forgiven, it won’t be on his watch. And Trump might believe he can weaponize the payroll tax deferral against obstinate Democrats in Congress as well as Joe Biden. Maybe he can.

False Positives, False Cases, False Deaths

14 Monday Sep 2020

Posted by in Coronavirus, Pandemic

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The tremendous increase in testing for COVID-19 (C19) this summer was associated with an increase in cases. Most of these tests were so-called PCR tests with samples collected via deep nasal swabs. More testing did not fully explain the increased case load, but false positives (FPs) still accounted for a substantial share. That’s especially true in light of the decline in positivity rates, which reflected a decline in the actual prevalence of active infections. FPs also account for a substantial share of the deaths attributed to COVID, which are obviously cases of false attribution. If a test for C19 is positive, it will be listed on the death certificate.  

COVID Case Inflation

The exaggeration of confirmed cases due to FPs is more substantial as the prevalence of active infection declines. That’s because the share of true positives in the tested population declines, while the share of false positives must rise due to the greater share of uninfected individuals in the population.

Now, as the contagion is waning in former hot spots, there is a danger that FPs create the impression of persistence in the case counts. That’s costly not just for those incorrectly diagnosed, but also in terms of medical resources, for communities subject to excessive public intervention, such as inappropriate lockdowns, and in terms of the fear promoted by these inaccuracies.

FPs are extremely disruptive when testing is relied upon in critical situations such as health care staffing, or even among sports teams. For example, at the University of Arizona, out of 25 positive tests on September 3, only 10 were confirmed as positives in later tests. The NFL has also had its share of false positives. 

Lax Testing Standards

There is evidence that testing standards under CDC guidance are so broad that a large number of inactive, non-infectious cases are being flagged as positives (see the chart above for the intuition, as well as the graphic at the bottom of this post). The tests sometimes amount to a coin flip when it comes to evaluating positives; some of the positives might even come from non-novel coronaviruses such as the common cold! This paper by Andrew N. Cohen, Bruce Kessel, & Michael G. Milgroom – CKM) questions the guidance of public health authorities on testing more generally. From the abstract (my emphasis):

“Unlike previous epidemics, in addressing COVID-19 nearly all international health organizations and national health ministries have treated a single positive result from a PCR-based test as confirmation of infection, even in asymptomatic persons without any history of exposure. …  positive results in asymptomatic individuals that haven’t been confirmed by a second test should be considered suspect.”

False Positive Math

When I wrote about “The Scourge of False Positives” in July. I noted that a test specificity of 95% implies that 5% of uninfected individuals will falsely test positive. Unfortunately, that still produces a huge number of FPs when testing is broad. That’s NOT a good reason to avoid broad testing; it just means that positive tests should be confirmed by another test. (In this case, two tests with the same specificity reduce a 5% false positive rate to 0.25%. That’s why fast, cheap tests are necessary for confirmation.

Again, exaggerated case counts due to FP’s become more severe as a contagion wanes. That’s because FPs become an increasingly large share of positive test results and overstate the persistence of the virus. If active infections fall to 1% of 750,000 daily tests, or 7,500 true cases, the 5% specificity implies 37,125 FPs: true positives would be only 17% of positive cases. Much worse than a coin flip! And again, which cases are infectious?

How Bad Are FPs, Really?

This recent research, also authored by CKM, explains the reasons why FPs are usually an issue in the real world, despite the tests’ reportedly perfect reactivity to anything other than the virus’ genetic fragments. CKM find that the median FP rate in their sample of “tests of tests” was 2.3%. That means 23 out of every 1,000 uninfected people tested will test positive.

If that seems small to you, suppose the true prevalence of active infection in a population is 4%. If 1,000,000 people are tested and there are no false negatives (unlikely), then 40,000 infected people will be identified by the test. However, another 22,000 uninfected people will also test positive ((1,000,000 – 40,000 infected) x 0.023). That means the number of positive tests will be inflated by 55%. They’ll all receive some form of treatment or ordered into quarantine. Expanded Testing and FPs This summer, the volume of daily tests increased from about 150,000 a day in early April to more than 750,000 a day in July. That’s a 400% increase, but the true prevalence of active infection in the expanded test population during the summer was almost certainly lower than in the spring. Suppose active infections fell from 10% of the test population in the spring to 5% in the summer. That means the daily number of “true positives” would have risen from 15,000 to 35,000 in the expanded test population (and again I assume no false negatives for simplicity). The number of FPs, however, would have risen from 3,105 to 16,445. Therefore, FPs would have accounted for 40% of the increase in “confirmed” cases between spring and summer.

False COVID Deaths

FPs are also inflating COVID death counts. PCR tests are routinely given at hospital admission for any cause, and even after sudden death, especially as the availability of tests increased late in the spring. This subset of the tested population will certainly have its share of FPs. If such a patient dies, regardless of underlying cause, it might well be attributed to COVID-19 as it will still appear on the death certificate. The same has occurred in the case of traffic fatalities, suicides, and other sudden deaths.

Antibody Tests

The FP problem also plagues tests of seroprevalence, which determine whether an individual has had the virus or is cross-protected against the virus by antibodies acquired via non-novel coronavirus infections. The consequences of these antibody FPs can be serious as well, because it means a positive test might not ensure immunity. As the exposed share of the population increases, however, the FP share of antibody tests is diminished.

Conclusion

As long as testing is required, dealing with FPs (and false negatives, of course) requires repeated testing, as CKM state unequivocally. And the tests must be fast to be of any use. The current testing regime must be overhauled to prevent false positives from costly impositions on the lives of uninfected patients, consuming unnecessary medical resources, making unrealistic assessments of cases and deaths, and unnecessary suspensions of normal human social activity and liberty.

Union Control, Shuttered Schools, COVID Risk

07 Monday Sep 2020

Posted by in Coronavirus, Education, Unions

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Public schools are closed in favor of virtual classrooms in some areas. Elsewhere, however, schools have physically reopened to the children of willing parents. It should be no surprise that the varying strength of teachers’ unions has a lot to do with these decisions. One cannot claim that the pattern of closures is a response to varying levels of COVID risk, as there is no geographic association between the closures and COVID cases or deaths. The shame of it is that closures compromise learning and also have destructive effects on local labor markets and the ability of parents to earn incomes.

That unions play this role, often decisively, is shown in a new paper entitled “Are School Reopening Decisions Related to Union Influence?“, by Corey DeAngelis and Christos Makridis (HT: Tyler Cowen). The authors examine the fall reopening decisions of 835 school districts and find that “… districts in locations with stronger teachers’ unions are less likely to reopen in person…“. The authors test four different measures of union strength with similar findings. They also rule out potential confounding influences like voting patterns.

Shall we defend the unions for protecting their members from excessive risk? Well, another important finding reported by the authors won’t surprise anyone having the least familiarity with data on C19 risks:

“We also do not find evidence to suggest that measures of COVID-19 risk are correlated with school reopening decisions.”

Few children catch the virus and children are not effective at transmitting C19 to their peers, teachers, and parents. Furthermore, schools closed to in-person learning are not located in areas at elevated risk relative to those remaining open.

The role of teachers’ unions in school reopening decisions is a textbook case of the inadvisability of unionized public employees. Most obviously, it is in their interests to encourage greater funding and taxes. This is but one of many dimensions of the political agendas that teachers’ unions may advance, and to which member dues are put. These are not always representative of members’ views, which is especially problematic in states without right-to-work laws.

The very nature of public service means that the work of public employees (or its absence) has profound external influences on the community at large. The unions are not shy about using this power as leverage in negotiations. Thus, teachers’ unions often act as adversaries not only to taxpayers, but to parents, children, and the business community.

Do public school administrators and elected school board members belong on the list of union adversaries as well? Perhaps: the unions have bullied school districts and have made them less attractive as educational institutions in a cost-benefit sense. In the present case, the unions have successfully lobbied for ongoing payments of income and benefits to their members despite the degraded effectiveness of on-line instruction for many K-12 students. Meanwhile, many parents are learning to exercise choice in the matter by abandoning public schools in favor of private alternatives.

Not News: Infections and Long-Term Complications

06 Sunday Sep 2020

Posted by in Coronavirus, Health Care

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At 15 years of age I was diagnosed as a Type I diabetic — 49 years ago. I had a genetic predisposition, but I’ve been told by several endocrinologists over the years that an “event” likely triggered the antibody response for which I was predisposed. The event was, in all probability, a viral or bacterial infection. The autoimmune response to that infection attacked the islet cells in my pancreas and destroyed my body’s ability to produce insulin. I’ve been dependent on external delivery of insulin ever since. Life goes on.

I relate this information to emphasize that it is not “novel” for a virus to trigger long-term “complications”. Recently, certain media factions have been shrieking about the long-term complications that might be triggered by the coronavirus (C19) even in those with otherwise light symptoms. Those are unfortunate, but again, this aspect of viral and bacterial infection is not uncommon.

We know, for example, that bacterial and viral infections often trigger autoimmune diseases like diabetes. Other examples are chronic fatigue syndrome, fibromyalgia, rheumatoid conditions, celiac disease, Graves’ disease, Guillain-Barré syndrome, Sjogren’s Syndrome, multiple sclerosis, and many others.

One condition that’s been cited as an especially dangerous complication of C19 is myocarditis, or inflammation of the heart muscle. This has been invoked as a reason to cancel sports competitions, for example. (See here for a denial of one rather hyperbolic claim regarding this condition.) Myocarditis has a long history as a side effect of influenza. Most people recover with no long-term complications, and others manage to live with it and remain productive. While C19 is “novel”, infection-induced myocarditis is not.

If you catch a virus or a bacterial infection, you might experience other complications with varying severity. Get used to the idea. It’s an unfortunate fact of life.

COVID Immunity, Herd By Herd

01 Tuesday Sep 2020

Posted by in Coronavirus, Herd Immunity

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Too many public health authorities remain in denial, but epidemiologists are increasingly convinced that heterogeneity implies a coronavirus herd immunity threshold (HIT) that is greatly reduced from traditional models and estimates. HIT is the share of the population that must be infected before the contagion begins to recede (and the transmission ratio R falls below one). Traditional models, based on three classes of individuals (Susceptibles, Infectives, and Recovered – SIR), predict a HIT of 60% or more. However, models that incorporate variation in susceptibility, transmissibility, and occupational or social behavior reduce the HIT substantially. Many of these more nuanced models show that the HIT could be in a range of just 15% to 25%. If that is the case, many regions are already there!

For background, I refer you to the first post I wrote about heterogeneity in late March, more detailed thoughts from early May, examples and more information on the literature later in May. I’ve referenced it repeatedly in other posts since then. And now, more than five months later, even the slow kids at the New York Times have noticed. The gist of it: if not everyone is equally susceptible, for example, a smaller share of the population needs to be “immunized via infection” to taper the spread of the virus.

Some supporting evidence appears in the charts below, courtesy of Kyle Lamb on Twitter. The first chart shows a seven-day average of C19 cases per million of population for ten states that reached an estimated 10% antibodies. These antibodies confer at least short-term immunity against C19. Most of these states saw cases/m climb at least through the day when the 10% level was reached, though Rhode Island appears to have been an exception.

The second chart shows the seven-day average of cases/m in the same states starting seven days after the 10% immunity level was reached. I’d prefer to see the days in the interim as well, but the changes in trend are still noteworthy. All of these states except Louisiana had a downturn in the seven-day average of new cases within a few weeks of breaching the 10% infection level (Louisiana had distinct and non-coincident outbreaks in different parts of the state). These striking similarities suggest that things turned as the infection level reached 15% or more, consistent with many of the epidemiological models incorporating heterogeneity.

Next, take a look at the states in which C19 surged most severely this summer. The new cases are not moving averages, so the charts are not quite comparable to those above. However, the peaks seem to occur prior to the breach of the 15% infection level.

Speculation about early herd immunity has been going on for several months with respect to various countries and even more “micro” settings such as cruise ships and military vessels, where populations are completely isolated. Early on, this “early” herd immunity was discussed under the aegis of “immunological dark matter”, but we know now that T-cell immunity has played an important role. In any case, anti-body expression (or seroprevalence) at around 20% has been linked to reversals in C19 cases and deaths in several countries. As Yinon Weiss notes, New York City and Stockholm were both C19 hotspots in the spring, both have seen deaths decline to low levels, and they have little in common in terms of public health policy. London as well. The one thing they share are similar levels of seroprevalence.

An important qualification is that herd immunity is not relevant at high levels of aggregation. That is, herd immunity won’t be achieved simultaneously in all regions. The New York City metro area might have reached its HIT in April, but Florida (or perhaps only Miami) might have reached a HIT in July. Many areas of the Midwest probably still aren’t there.

In the absence of a new mutation of C19, the final proof of herd immunity in many of the former hotspots will be in the fall and winter. We should expect at least a few cases in those areas, but if there are more intense contagions, they should be confined to areas that have not yet seen a level of seroprevalence near 15%.

Teachers Face Low-to-Moderate COVID Risk

29 Saturday Aug 2020

Posted by in Education, Pandemic, School Choice, Uncategorized

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A quick follow-up to my recent post “COVID Hysteria and School Reform“: the graphic above is from an occupational risk study recently conducted by Swedish health authorities. The horizontal axis is obscured by the lower banner from Twitter (my fault), but the average risk of infection across all occupations was slightly less than 1%, and the highest-risk occupations were in the 4 – 5% range. Keep in mind, the data was collected while the virus was still raging in Sweden, while schools remained open. The virus hasn’t completely vanished in Sweden since then, but it has largely abated.

The study found that teachers had roughly average or below average risk, especially for pre-school and upper secondary (so-called “gymnasium”) teachers. The results demonstrate the lack of merit to claims by teachers unions that their members are somehow at greater risk of contracting coronavirus than other “essential” workers. We already know that children have extremely low susceptibility to COVID-19 and that they do not readily transmit the virus.

The health benefits of closing schools or taking them on-line do not compensate for the loss of educational effectiveness and detrimental health effects of preventing children from attending schools. The digital divide between children from disadvantaged households and their peers is likely to grow more severe if online learning is their only option. They should have choices, including functioning public schools.

To the last point, however, read this link for the sort of thing one teachers union supports. If the members are okay with that insanity then they shouldn’t be teaching your kids.

COVID Hysteria and School Reform

24 Monday Aug 2020

Posted by in Education, Pandemic, School Choice

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Many haven’t quite gathered it in, but our public education system is an ongoing disaster for many low-income and minority students and families. The pandemic, however, is creating a major upheaval in K-12 education that might well benefit those students in the end. But before I get into that, a quick word about National Public Radio (NPR): it doesn’t make its political leanings a secret, which is why it should not be supported by taxpayers. Yes, like many other mainstream media outlets, NPR serves as a political front organization for Democrats (and worse).

Last week, NPR did a segment on “learning pods”, which I’d describe as private adaptations to the failure of many public schools (and teachers’ unions) to do their job during the pandemic. Glenn Reynolds passed along an interpretation of that NPR segment from a friend on Facebook, which I quote in its entirety below (bold emphasis mine). It was either this segment or else NPR has taken it down … but that link more or less matches the description. The post is somewhat satiric, but it captures much of what was actually said:

“Hilarious NPR, last week’s edition. They had an hour-long segment on learning pods. Participants: Host (white woman), Black Woman Activist, Asian Woman Parent, School-System Man.

Slightly editorialized (but true!) recollections below.

Host: In wealthy areas, parents get together and organize learning pods. What do we make of it?

School-System Man: Inequitable! Inappropriate! Bad! We do not support it!

Asian Woman Parent: Equity requires that we form these pods to educate our own children! Otherwise, only the rich can get education! Rich bad!

Host: Rich bad.

School-System Man: Rich horrible! They withdraw kids from public schools during the pandemic, so schools have less money!

Asian Woman Parent: We have no choice. You are not teaching.

Host: But what are you doing for the equity?

Asian Woman Parent: Why are the parents supposed to be doing something for the equity? That’s why we pay taxes, so professionals do something!

School-System Man: We cannot fix equity if you are clandestinely educating your own children, but not everyone else’s children!

Asian Woman Parent: The proper solution would have been to end the pandemic. But Trump did not end the pandemic. So, we must do learning pods. As soon as the pandemic is over, we’ll get back to normal, and everyone will catch up.

Everyone [with great relief]: Trump bad. Bad.

Black Woman Activist: No, wait a minute. This sounds as though in a regular school year, black children get good education. And they are getting terrible education! Unacceptable!

Host: Bad Trump!

Black Woman Activist: Foggeraboutit! It’s not Trump! It’s always been terrible! Black children are dumped into horrible public schools, where nobody is teaching them! So, my organization is now helping organize these learning pods for minority kids everywhere.

School-System Man [cautiously]: This is only helping Trump…

Black Woman Activist: Forget Trump! Don’t tell me black kids get no education because things are not normal now. When things were normal, their education was just as bad!

School-System Man: Whut??? How dare you! Our public schools are the best thing that ever happened to black children.

Asian Woman Parent: I’ll second that. Public schools in my neighborhood are just svelte.

Black Woman Activist: That’s the point! You live in a rich suburb, and your kids get a great public school! Black kids don’t!

Asian Woman Parent: If Trump managed the pandemic properly, we would not be having this conversation.

Host: Bad Trump!

Everyone: Bad Trump!

The end.”

Ah yes, so we’re back to blaming Donald Trump for following the advice of his medical experts, most prominently Dr. Anthony Fauci. And, while we’re at it, let’s blame Mr. Trump for following federalist principles by deferring to state and local governments to deal flexibly with the varying regional conditions of the pandemic, rather than ruling by federal executive edict. Of course, some of those state and local officials botched it, such as Andrew Cuomo. That’s tragic, but had Trump followed a more prescriptive tack, the howling from the Left would have been even more deafening.

We know that children are at little risk from the coronavirus. Nor do they seem to transmit the virus like older individuals, but teachers unions are adamant that the risks their members face at school would far exceed those shouldered by other “essential” workers. And the unions, not shy about partisanship even while representing public employees, want nothing more than to see Trump lose the election. So the unions and the schools districts they seem to control hold parents hostage. They collect their tax revenue and salaries while delivering virtual service at lower standards than usual, or no service at all. (Of course, public schools in some parts of the country are in session.) 

The teachers’ unions and public schools might get their comeuppance. The situation represents a tremendous opportunity for private schools, home schooling, and innovative schooling paradigms. Many private schools are holding classes in-person, more parents are homeschooling, and alternative arrangements like learning pods have formed, many of which are quite cost-effective.

Pressure is building to allow education dollars to follow individual students, not simply to flow to specific government schools. You can buy a decent K-12 education for $12,000 a year or so, and it’s likely to be a better education than you’ll get in many public schools. (One of the panelists on the NPR segment smugly called this an “insidious temptation”). At long last, parents would be allowed real choice in educating their children, and at long last schools would be incentivized to compete for those students. That might be one of the best things to come out of the pandemic.

COVID Seasonality and Latitudes

23 Sunday Aug 2020

Posted by in Pandemic

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The coronavirus (C19), or SARS-CoV-2, has a strong seasonal component that appears to closely match that of earlier SARS viruses as well as seasonal influenza. This includes the two distinct caseloads we’ve experienced in the U.S. 1) in the late winter/early spring; and 2) the smaller bump we witnessed this summer in some southern states and tropics. 

COVID Seasonal Patterns and Latitude

The Ethical Skeptic on Twitter recently featured the chart below. It shows the new case count of C19 in the U.S. in the upper panel, and the 2003 SARS virus in the lower panel. Both viruses had an initial phase at higher latitudes and a summer rebound at lower latitudes.

 

 

 

 

 

 

 

 

 

 

I particularly like the following visualizations from Justin Hart demonstrating the pandemic’s pattern at different latitudes (shown in the leftmost column). The first table shows total cases by week of 2020. The second shows deaths per 100,000 of population by week. Again, notice that lower latitudes have had a crest in the contagion this summer, while higher latitudes suffered the worst of their contagion in the spring. Based on deaths in the second table, the infections at lower latitudes have been less severe.

Viral Patterns in the South

Many expected the pandemic to abate this summer, including me, as it is well known that viruses don’t thrive in higher temperatures and humidity levels, and in more direct sunlight. So it is a puzzle that southern latitudes experienced a surge in the virus during the warmest months of the year. True, the cases were less severe on average, and sunlight and humidity likely played a role in that, along with the marked reduction in the age distribution of cases. However, the SARS pandemic of 2003 followed the same pattern, and the summer surge of C19 at southern latitudes was quite typical of viruses historically.

A classic study of the seasonality of viruses was published in 1981 by Robert Edgar Hope-Simpson. The next chart summarized his findings on influenza, seasonality, and latitude based on four groups of latitudes. Northern and southern latitudes above 30° are shown in the top and bottom panels, respectively. Both show wintertime contagions with few infections during the summer months. Tropical regions are different, however. The second and third panels of the chart show flu infections at latitudes less than 30°. Influenza seems to lurk at relatively low levels through most of the year in the tropics, but the respective patterns above and below the equator look almost like very muted versions of activity further to the north and south. However, some researchers describe the tropical pattern as bimodal, meaning that there are two peaks over the course of a year.   

So the “puzzle” of the summer surge at low latitudes appears to be more of an empirical regularity. But what gives rise to this pattern in the tropics, given that direct sunlight, temperature, and humidity subdue viral activity?

There are several possible explanations. One is that the summer rainy season in the tropics leads to less sunlight as well as changes in behavior: more time spent indoors and even less exposure to sunlight. In fact, today, in tropical areas where air conditioning is more widespread, it doesn’t have to be rainy to bring people indoors, just hot. Unfortunately, air conditioning dries the air and creates a more hospitable environment for viruses. Moreover, low latitudes are populated by a larger share of dark-skinned peoples, who generally are more deficient in vitamin D. That might magnify the virulence associated with the flight indoors brought on by hot and or rainy weather.   

Mutations and Seasonal Patterns

What makes the seasonal patterns noted above so reliable in the face of successful immune responses by recovered individuals? And shouldn’t herd immunity end these seasonal repetitions? The problem is the flu is highly prone to viral mutation, having segments of genes that are highly interchangeable (prompting so-called “antigenic drift“). That’s why flu vaccines are usually different each year: they are customized to prompt an immune response to the latest strains of the virus. Still, the power of these new viral strains are sufficient to propagate the kinds of annual flu cycles documented by Hope-Simpson.

With C19, we know there have been up to 100 mutations, mostly quite minor. Two major strains have been dominant. The first was more common in Southeast Asia near the beginning of the pandemic. It was less virulent and deadly than the strain that hit much of Europe and the U.S. Of course, in July the media misrepresented this strain as “new”, when in fact it had become the most dominant strain back in March and April.

What Lies Ahead

By now, it’s possible that the herd immunity threshold has been surpassed in many areas, which means that a surge this coming fall or winter would be limited to a smaller subset of still-susceptible individuals. The key question is whether C19 will be prone to mutations that pose new danger. If so, it’s possible that the fall and winter will bring an upsurge in cases in northern latitudes both among those still susceptible to existing strains, and to the larger population without immune defenses against new strains.

Fortunately, less dangerous variants are more more likely to be in the interest of the virus’ survival. And thus far, despite the number of minor mutations, it appears that C19 is relatively stable as viruses go. This article quotes Dr. Heidi J. Zapata, an infectious disease specialist and immunologist at Yale, who says that C19:

“… has shown to be a bit slow when it comes to accumulating mutations … Coronaviruses are interesting in that they carry a protein that ‘proofreads’ [their] genetic code, thus making mutations less likely compared to viruses that do not carry these proofreading proteins.”

The flu, however, does not have such a proofreading enzyme, so there is little to check its prodigious tendency to mutate. Ironically, C19’s greater reliability in producing faithful copies of itself should help ensure more durable immunity among those already having acquired defenses against C19.

This means that C19 might not have a strong seasonal resurgence in the fall and winter. Exceptions could include: 1) the remaining susceptible population, should they be exposed to a sufficient viral load; 2) regions that have not yet reached the herd immunity threshold; and 3) the advent of a dangerous new mutation, though existing T-cell immunity may effectively cross-react to defend against such a mutation in many individuals.

 

The FDA Can Put Virus Behind Us, Sans Vaccine

19 Wednesday Aug 2020

Posted by in Liberty, Pandemic, Vaccinations

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Most of the news about COVID vaccine development is positive, but there are still huge doubts about 1) whether an effective vaccine(s) will ever be available; 2) when it will be available; 3) in what quantities (supply chains for vaccines present issues that most lay persons would never imagine) ; 4) the best approaches to allocation across young/healthy vs. old/vulnerable; 5) how long it will provide protection (the news is good on lasting immunity as well); and 6) whether people will actually take it. Given all these uncertainties, it’s worth considering an approach to stanching the coronavirus that won’t require a vaccine while still allowing a return to normalcy: cheap, rapid tests available to consumers on a daily basis in their homes or in businesses.

The full benefits of cheap, rapid tests can take people a while to wrap their heads around. In fact, there are skeptics who’s views on any and all testing are colored by suspicions that increased testing is some sort of conspiracy to spread fear and keep the economy hobbled. It’s true that increased testing drove much of the increase in COVID cases this summer, which caused the mainstream media to delight in spinning alarmist narratives. Fair enough, but that misses the point, which I’ll try to elucidate below. I credit a John Cochrane post for bringing this to my attention.

A successful vaccine breaks the so-called “transmission chain”, but so does frequent testing to identify infectious individuals on an ongoing basis so they can self-quarantine. As Alex Tabarrok has emphasized, we should worry about identifying infectious individuals, as opposed to infected individuals. They are not the same. Cheap, rapid, and easy-to-administer tests have already proven to be fairly accurate during the infectious stage. The idea is for individuals to self-test every day and stay home if they are positive. Or, employers can test workers every day and send them home if they are positive. Frequent testing also makes it simpler to trace the source of an infection and may reduce the importance of tracing.

To those who say this represents an affront to personal liberty, and I’m very touchy on that subject myself, recall that even now people are being screened in their workplaces using thermometers, questionnaires, or on the basis of any frogginess perceived by supervisors and co-workers. Those “tests” are far less accurate in identifying COVID-19 contagiousness than the kinds of cheap tests at issue here, and they are certainly no less intrusive. Then there are the many businesses facing restrictions on their operations: how “accurate” is it to keep everyone at home by locking down places of business? How intrusive is that? Those restrictions are indefensible, and especially with the advent and diffusion of cheap, rapid tests.

Of course, people might cheat and not report positives. Tests could be administered at workplaces to avoid that possibility, or at points of admission to businesses and facilities, but a few minutes of delay would be necessary. I would not support a centralized database of daily test results. If nothing else, relying on the good faith of individuals in reporting their results would be a giant leap forward in breaking the transmission chain now, rather than counting on the possibility of a successful virus in the indefinite future. And we might then avoid the whole pro-vax/anti-vax imbroglio that already foments, which raises major questions bearing on individual liberty.

Then there is the question of positive tests within multi-person households. Should the entire family or household self-quarantine? I say no, not if the others are negative, but then the others should test twice before going out, which dramatically reduces the probability of a false negative, and they should probably test more frequently, perhaps several times a day.

There are other important details to address: Who will pay for the tests? Will workers be paid to stay home if they test positive? How long will they be required to stay home? How will repeated tests be treated? I don’t want to get into detail on all of these points, but cheap, fast tests can help overcome many of these difficulties, and I believe many of the details can and should be worked out privately.

Unfortunately, the FDA has approved only two rapid tests, and they are not very rapid and not cheap enough. Only one had been approved up until last weekend because the FDA found the accuracy to be lacking … compared to PCR tests! But the FDA finally issued an Emergency Use Authorization for a saliva-based test (SalivaDirect) developed at Yale, partly funded by the NBA and the Players Association. The test still requires processing at a lab, so it’s really not convenient enough and not fast enough. Here is Zach Lowe on the cost:

“The cost per sample could be as low as about $4, though the cost to consumers will likely be higher than that — perhaps around $15 or $20 in some cases, according to expert sources.”

Not bad, but it’s much higher than more rapid, paper tests developed by Harvard’s Wyss Institute for Biologically Inspired Engineering and a company called E25Bio. Both of those are expected to cost about $1 per sample and can be completed anywhere. That’s a price that can work. And there are other promising candidates.

The benefits of tests that are rough, ready, and cheap will be huge. Such tests will also enable retesting, which helps to overcome the dilemmas of false positives and negatives. False negatives might be of greater concern to the FDA, but again, false negatives are less likely during the contagious stage of an infection, and the tests will be accurate enough that transmission risk will be drastically reduced.

The FDA needs to move beyond its stodgy insistence on achieving laboratory levels of accuracy. It’s unlikely that a single test source will be adequate to stanch the transmission chain, so the agency should rush to approve as many cheap, rapid tests as possible, with as many advisories and patient warnings regarding test results and follow-up instructions as it deems necessary. Remember, these tests are much better than thermometers!

Evidence of Fading COVID Summer Surge

16 Sunday Aug 2020

Posted by in Pandemic

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Lately I’ve talked a lot about reported deaths each week versus deaths by actual date of death (DOD). Much of that information came from Kyle Lamb’s Twitter account, and he’s the source of the charts below as well. The first one provides a convenient summary of the data reported through last week. The blue bars are reported deaths each week from the COVID Tracking Project (CTP), which are an aggregation of deaths that actually occurred over previous weeks. Again, the blue bars do NOT represent deaths that occurred in the reporting week. The solid orange bars are “provisional” actual deaths by DOD. “Provisional” means that recent weeks are not complete, though most deaths by DOD are captured within three to four weeks. The CDC also produces a “forecast” of final death counts by DOD, shown by the hatched orange bars.   

Note that the recent surge in deaths has been much smaller than the one in the spring, which was driven by deaths in the northeast. The CDC “expects” actual deaths by DOD to have declined starting after the week of July 23rd. However, CTP was still reporting deaths of over 1,000 per day last week. The actual timing of those deaths in prior weeks, and the ultimate extent of the summer surge in COVID deaths, remains to be seen.

Certain leading indicators of deaths are signaling declines in actual deaths in August. Two of those indicators are 1) the positivity rate on standard PCR tests for infections; and 2) the share of emergency room visits made for symptoms of “COVID Like Illness” (CLI). The charts below show those indicators for FEMA regions that had the largest uptrends in cases in June and July. Florida is part of Region 4, shown in the next chart:

Here is the Region 6, which includes Texas:

Finally, Region 8 includes Arizona and California:

Out of personal interest, I’m also throwing in Region 7 with a few midwestern states, where cases have risen but not to the levels reached in Regions 4, 6, and 8:

With the exception of the last chart, the clear pattern is a peak or plateau in the positivity rate in late June through late July, followed by declines in subsequent weeks. The share or ER visits for CLI was not quite coincident with the positivity rate, but close. The decline in the CLI share is evident in Regions 4, 6 and 8. Again, these three regions include states that drove the nationwide increase in cases this summer (AZ, CA, FL, and TX), and the surge appears to have maxed out.     

Here is a chart showing the share of CLI visits to ERs for all ten FEMA region from mid-June through last week. Clearly, this measure is improving across the U.S.

Nationwide, the CLI percentage at ERs has decreased by about 47% over the past four weeks, and the positivity rate has decreased by about 28% in that time. In addition to these favorable trends, COVID hospitalizations have decreased by about 40% over the past three weeks. All of these trends bode well for a downturn in COVID-attributed deaths.

The summertime surge in the virus was not nearly as ravaging as in the spring, and it appears to be fading. We’ll await developments in the fall, but we’ve come a long way in terms of protecting the vulnerable, treating the infected, approaching herd immunity thresholds (which means reduced rates of transmission to susceptible individuals), and the real possibility that we can put the pandemic behind us.