Wednesday, March 18, 2020

Is "The Curve" a Useful Model for Policy?

As Covid-19 has spread through the United States and the UK, so too has the meme of "flattening the curve" to reduce the strain on healthcare system capacity. The logic of flattening the curve is simple, by taking precautions to reduce the chance of contracting the virus, you reduce the number of new patients. This gives medical facilities the opportunity to let patients recover fully under their care without having to discharge early or restrict admission on the basis of medical priority.

Unfortunately, this model requires fairly extreme measures that have come under the rubric of "social distancing." The will to social distancing has varied across the country with some places offering widely-ignored health recommendations and others putting their jurisdictions on lock down enforced by the police.

At the furthest extreme, we are looking at the macroeconomic equivalent of a general strike in order to flatten the curve. With some projections claiming that social distancing may be required for a year or more, it's unclear what exactly the virus response is saving us from. What is clear, is that relying on the natural spread of the virus is not a viable option.

Assessing the Problems

The virus provides us with a number of competing problems that the epidemiological model of "the curve" make appear impossible to resolve. Primary among these problems are:

The Medical System

  • The limited number of available tests
  • The limited capacity of hospitals
  • Shortages of medical professionals due to contracting the virus
  • Shortages of medical equipment and supplies
  • Intake and triage bottlenecks

Uncontrolled Disease Vectors

  • Asymptomatic people spreading the disease
  • Mildly symptomatic people spreading the disease
  • People spreading the disease in healthcare facilities

The Economic System

  • Widescale losses of personal and business income
  • Widescale drawdown of production
  • Disruption of supply chains
  • Sudden Ponzi financing of corporate debt (Paying off debt with more debt)
  • Unreliable price system due to financial market turmoil
  • Real economy cannot be stimulated (evenly) through fiscal or monetary policy

The longer this crisis, the more severe these problems can be expected to become–particularly the economic ones.

The Problem with "The Curve"

While the curve does lead to good advice as far as individual habits are concerned, it is not very instructive for policy. It is certainly beneficial for hospitals who are seeing patient surges to have you postpone individually contracting and spreading the virus. However, the economic effects of such measures, particularly those that have been institutionalized through emergency action, threatens to deal us an equally severe death blow in the form of economic privation.

Chief among the issues with using the curve as a policy model is that it fails to include variables necessary to form a comprehensive public health response to the crisis. Further, it fails to take into account the effects of a long-term policy response to the virus, particularly the impacts it will have on the healthcare sector.

The Patient Count Line

Every mathematical model requires some degree of abstraction from the on-the-ground reality of the situation being explored. This means simplifying the information into simple measurements that we can use to express relationships between phenomena. However, in doing this abstraction, we must ensure that the measurements remain useful in helping us understand what it is we want to solve.

The patient count in the curve allows us to show that generally we, as random individuals, can collectively reduce the strain on the healthcare system by postponing our contraction of the virus. However, as far as policy is concerned, we are not random individuals, and we do not all have to end up on the curve.

In its severe abstraction, the curve misses key facts that we now know about the virus that can be instrumental in designing a proactive response to the disease that allows us to accelerate to the point of widescale inoculation while minimizing uncontrolled spread. These facts include:

  • Not all cases of the virus produce symptoms severe enough to require hospitalization, or produce symptoms at all.
  • The severity of the symptoms and their lethality seems to vary with age and overall health among other knowable factors.
  • Patients' interaction with the healthcare system is not uniform.

The flattened curve further fails to account for the crumbling of social distancing measures as economic strains become too much to bear for either households, businesses, or the patience of conservatives in government.

The Healthcare Capacity Line

We can expect that as more sectors of the economy shut down, more payments missed, and more bankruptcies declared, the problems for healthcare will only get worse. Shortages of medical equipment and supplies will increase as downstream production slowdowns catch up with the supply chain. Leveraging in the healthcare sector may cause lines of credit to dry up, impacting the ability of healthcare facilities to pay their employees.

Thus it might be more accurate to depict the capacity of the healthcare system as a decreasing function of the number of patients/workers or possibly one that decreases autonomously as the result of quarantine policy. What we can say for sure, however, is that it will be very unlikely that it remains constant.

Further, the healthcare capacity line presumes a homogeneity within the healthcare system that does not exist. If everyone showing symptoms rushed to the emergency room, that would put far more strain on the hospital system than if people visited primary care physicians for testing.

Two Proposed Solutions

There have already been a number of solutions proposed as far as pure economic policy goes. In addition to the monetary policy measures currently underway, political leaders and commentators have variously offered as solutions:

  • Healthcare coverage relating to testing and treatment
  • Some form of basic income
  • Rent and mortgage freezes
  • Subsidies for businesses
  • Moratoria on utility shut offs
  • Bailouts or nationalization of major industries
  • Federal assistance to state and local governments
  • Relaxation of public assistance qualifications

As I discussed in my previous post, all of these are great short-term measures, but the longer production remains suppressed by pandemic containment measures, the more disruptions there will be in supply chains as payment arrangements break down.

In my view, we cannot view our economic policy as separate from our health policy. If we do, we are stuck with the curve, trying to calibrate a response that ensures a certain rate of transmission in a trade-off between healthcare facility admission rates and length of the crisis. Rather we can use our health and economic policies to complement each other.

A Blue New Deal

Currently there is a pressing need for medical equipment and supplies. Although not as efficient as factory production, many of these goods can be at least partly produced at home from materials or with the assistance of a 3D printer. Open up online applications, and develop a logistics system that gets materials to people's homes, pays them for their output, and gets finished products to where they can be sterilized.

Controlled Inoculation

An early proposal in the UK by the government of Boris Johnson suggested developing herd immunity to the virus naturally. This was widely rebuked as little more than a eugenicist fantasy, as the likely casualties from such a policy would be massive while waiting for herd immunity to establish itself.

Herd immunity is one of the principle reasons vaccine proponents advocate always staying up to date with all of your shots. The idea is that if enough of the population is immune to a disease, that disease won't be able to find enough viable hosts to spread. Unfortunately, for herd immunity to take effect, immunity rates need to be upwards of 60%, a number likely higher than would be exposed from containing the virus through social distancing.

However, just because letting the virus run rampant is an absolutely unconscionable proposal that marks the most vulnerable for death doesn't mean that aspiring to herd immunity is a lost cause. Rather, if we can control inoculation, I believe we can simultaneously arrest the uncontrolled spread of the virus while accelerating us to the end of the crisis.

The policy I am proposing would allow people meeting certain health and lifestyle qualifications volunteer to be infected with the virus and quarantine under supervision of their primary care physician. There are numerous instances where I describe standards set by health officials. This would be a body comprised of relevant federal agencies determined by congress, but not including congress itself. In all likelihood, the standards they set would change over the course of this program, starting especially stringent, and gradually relaxing as more of the population is inoculated. The policy creates a procedure that looks like this:

  1. A potential candidate creates an account on the inoculation program's website and prints out a form.
  2. The candidate fills out the patient portion of the form which details information about their lifestyle, household, health history, family health history, and anything else health officials determine might be a risk factor for either a quarantine or a successful recovery.
  3. The candidate waits for the biological sample package to come in the mail.
  4. The candidate takes the form and the biological sample package to their primary care physician who does a routine physical as well as additional tests as required by health officials.
  5. The physician fills out the physician portion of the form detailing results from the physical.
  6. The physician takes the necessary biological samples and mails it along with the form back to health officials. (Postage covered.)
  7. If the candidate is cleared by health officials, they receive a package in the mail containing instructions on preparing for and living in quarantine, instructions for the physician, the virus applicator, test kits to determine if the infection has passed, and a check for one month's full-time salary at either the prevailing median wage of the county or the candidate's hourly wage or equivalent, whichever is higher, regardless of whether the candidate works full-time or at all.
  8. The candidate prepares everything they need for the quarantine according to the instructions provided.
  9. The candidate takes the package to their physician who, after reading and agreeing to the care instructions, administers the virus applicator, preferably in the patient's home.
  10. The candidate quarantines in their own home, and is checked on regularly, by phone and in person according to a schedule set by health officials, by their physician who is also on call. The physician documents the course of the illness for health officials to use in epidemiological analyses.
  11. The candidate remains in quarantine until the physician determines they are no longer infected according to the instructions of health officials.
  12. The candidate is sent some sort of identifier that they have been inoculated as an exemption for lockdown orders.

An Assessment of the Solution

Certainly, this solution is far from perfect. My contention, however, is that it would do more to reduce harm than any of the current policy approaches being applied or discussed.

As far as strain on the medical system goes, it eliminates at least one test per inoculated patient since the patient will already know that they are infected with the virus when they show symptoms. Further, it reduces patient contact with the hospital system since candidates would only resort to it for unique emergency treatment options their physician can't provide. Last, it provides a means of ensuring the production of necessary medical supplies while not risking the disease factory of centralized production.

As far as mitigating the spread, the plan will ensure that those who are most likely to transmit the disease asymptomatically or who may be inclined to weather mild symptoms know when they have the disease and quarantine from the moment they get it. This not only eliminates the candidate as a vector, but also the other people to whom the candidate would have spread the disease. It also reduces patients spreading the virus in waiting rooms while awaiting a test or throughout the hospital to staff.

If this plan is both successful and scalable, it could help avert economic calamity. Not only will it hasten the ability to call off production-slowing lockdowns, but it will also enable inoculated people to return to work without fear of contracting and spreading the virus while lockdowns are in place.

Lingering Concerns

This proposed plan, like the curve, assumes some basic things about the virus and its transmission. First, it assumes that there is an inoculation effect in surviving Covid-19. There are a small number of cases in China and Japan that may suggest that reinfection is possible, but these cases haven't been verified as reinfections versus relapses.

Second, this presumes a full recovery in inoculation candidates which might also not be a given. In numerous cases, we are seeing patients with lasting lung and kidney damage. In this case, there might need to be a permanent disability fund set up for those who volunteer to inoculate and walk away with conditions that impair their ability to work.

Last, there is the question of where to roll this plan out. For instance, does it make sense to clear a candidate for inoculation in a location that has yet to be exposed to the virus? What about areas where emergency health facilities are already pushed to capacity? These questions, like a lot of details in this proposal, must ultimately be ironed out by people with more expert knowledge.

What I am sure of, however, is the present reactive approaches will only give us a choice between pestilence and famine.