Why R we mindless?

Posted on by

When it comes to virus policy, to whom should we assign status and credibility? I propose that we severely downgrade the status of anyone who speaks in terms of R, or R0. That concept is not helpful. A society could have R well below the “magic number” of 1 and still have a lot of elderly people dying from the virus. A society could have an R above 1 while insulating its elderly and thus having a low death rate.

I keep coming back to the Avalon Hill metaphor, in which what matters is the attack factor and the defense factor. The attack factor is the amount of virus particles that you get hit with. You get hit with more when you spend several minutes in a closed environment with someone who is expelling a lot of virus, especially by coughing or sneezing or singing or yelling. The defense factor is the strength of your immune system, which depends mostly on your age.

I want to focus here on the defense factor. If we had a vaccine, that could give everyone a strong defense factor. To the extent that people who have had the virus are immune, then they have strong defense factors. Young people have strong defense factors. People over 70 presumably have weak defense factors. People with heart conditions or compromised immune systems have weak defense factors.

Is there a rigorous way to evaluate my defense factor? That is something I would like to see researchers working on. If I knew for sure that I have a strong defense factor, then I could be a lot more relaxed about resuming some of my favorite activities.

Although the defense factor is likely to fall on a continuum, for simplicity let us say that there are people of type H and type L, for high defense factors and low defense factors, respectively. I can imagine linking people’s behavior to their defense factors and also to the defense factors of people with whom they must interact.

–If you are type L, then you want to avoid getting the virus. This means only being in places where you can be sure that no one has the virus. If you must be around people who may have the virus (say, you are a health care worker), then you have to follow extreme safety protocols involving personal protective equipment and sanitizing afterward.

–If you are type H and you do not have to interact with people who are type L, then you can interact with whomever you want. Your only responsibility is to try to avoid inflicting a high attack factor on someone. If you do not have antibodies, then you may have the virus, so that you should wear a mask while indoors around people with whom you don’t live. If you have antibodies, then you are harmless to others, even without a mask.

–If you are type H and you have to interact with people who are type L, then you have to be certain that you do not have the virus. You are good to go if you have antibodies. Or if you have been strictly self-quarantining for two weeks. Or if you have reliably tested negative for the virus.

This approach does not try to drive R to any particular value. If R is high among type H people, that could be a good thing.

21 thoughts on “Why R we mindless?”

  1. Arnold;
    You are reflecting individual heterogeneity with respect to the virus – whether you are infected, whether you can readily be infected, how much you are shedding/how much you would shed if you were infected. It’s difficult to know which of these can be observed, how accurately they can be observed, how long the observation stays relevant – and how to prove your status to other people (‘reputation’ effects). It is the observation of some researchers that coronavirus resistance is a factor of short term immunological dips and sags – a bad night’s sleep, for example – and that immunity is uncertain, wavering, and fades rapidly at best. Some of the secrets of vaccinations is that many people don’t get a protective response the first time – though many do – and for those many vaccines the booster can help quite a bit, but not always. In short, we don’t understand all the variability around well-known vaccination responses. In those cases as well, it might be temporary status at the time of vaccination, or it can be individual variation.

    So how do we bundle all this up into well-founded self-knowledge and demonstrable reputation?

    • At the very least, we should be putting more research dollars into these questions and fewer research dollars into the modelers with there R’s.

      • Mathematical modelling is almost infinitely cheaper than medical experimentation, to the point where I don’t think they’re even competitors for each other.

        If you want to use a wargame model, I’m concerned that we’re using ablative armor. The disease seems to do permanent lung damage in over 70% of cases, even otherwise asymptomatic ones. A healthy 20-year old can ignore that easily once, or even twice, but probably not five times.

  2. WWCD? What would Coase do?

    I strongly suspect that he would support something very similar to what Arnold just put forth.

    Allocate the burden to the best cost avoider the most optimal solution will emerge.

  3. “A society could have an R above 1 while insulating its elderly and thus having a low death rate.”

    “If you are type H and you do not have to interact with people who are type L, then you can interact with whomever you want. ”

    You argument completely depends on the assertion that we can somehow maintain a viral barrier between the type L people and the type H people.

    Sure. Let’s pretend the absolute core of the problem doesn’t exist. Let’s just assume we can control where the virus does and does not spread. Makes perfect sense. Problem solved.

    • But isn’t this th very premise of social distancing? That we can control the viral barrier?

      It’s just with lockdowns we hope to control the barrier indiscriminately. With what is proposed it is more targeted.

      • We can increase the risk, or reduce it. We cannot control the viral barrier.

        We social distance, but nursing homes, even in their locked down state, have workers who must come and go. The attack factor that is described here comes from that exposure.

        Social distancing often fails to prevent an infection because almost none of us can do it 100%, but it can reduce the attack exposure enough so that the number of concurrent infections does not go up on net. That’s the premise of social distancing.

        Its all about containing concurrent infections from expanding to certain problematic thresholds. Any strategy that doesn’t do that is a certain to fail.

        If it does go up, before long the attack factor price goes up faster than the economic gain does.

        We can give more freedom to some H people by deploying more strategies to prevent concurrent infections from going up on net. But if we think we can let H people move about thinking they can tolerate more concurrent infections, and somehow we won’t kill lots more L people, we are delusional.

      • “We social distance, but nursing homes, even in their locked down state, have workers who must come and go. The attack factor that is described here comes from that exposure.”

        Bingo. From observation of the situation my parents were in, the lowly paid workers at these places are extremely high risk to be infected.

      • If we had sufficient, perfect testing we could do much more targeted isolation. But we don’t, so we can’t. Which means our choices are imperfect isolation or none at all.

  4. Arnold, what you suggest is basically Sweden’s strategy. Jury is still out on this. I hope that the experiment won’t be terminated prematurely.

      • Two strategies are available to us at this point, either slow the spread as long as possible and hope that we will get a vaccine or significantly improved treatment at some point, or allow a semi-controlled (semi because it attempts to segregate weakened immune systems from healthy) spread that will lead to herd immunity (Sweden’s strategy). Test and trace and social isolation are both variations of slow the spread, as neither can irradicate permanently a global virus. Which strategy we should pursue depends upon our wild-assed guess as to whether a vaccine or significantly better treatment will appear before civilization ends in economic ruin. At least, when we revert to hunter-gathering, it will slow the spread of future viruses.

        • MULTIPLE strategies are available.
          But minimize spread speed is one extreme. Minimize short term econ hit is another.
          Minimize long-term econ hit is similar, yet this is a different strategy with different result.
          Two key results – deaths,
          economic loss.

          In all cases, there is some unspoken tradeoff between deaths and econ; but whatever “strategy” / tradeoff point is chosen, there are better tactics and less good tactics.

          Doing NO special actions is one such tactic, unlikely to be optimal for any strategy. Wearing masks, social distancing, help for nursing homes and more protection for hospitals might be optimal for both — lowest deaths AND lowest econ. But this is a bit unlikely. There will probably be found better “lower death” actions, with higher econ losses; and lower econ losses, with higher deaths.

          (Plus there is the problem of “Covid-19” deaths, where it really needs to be excess deaths over what would have happened anyway, and no way to really know that but actuary tables could help on that.)

    • Sweden has under 19,000 concurrent cases and over 10M people(>.002). It remains to be seen if they can stabilize the growth in concurrent infections. Not looking great, but they had a couple of good days recently. As long as they can, they can do anything within that bound that works.

      I haven’t seen anything to suggest that Sweden views their strategy anything like the high defense/high freedom ideas expressed here.

        • The link you posted is the same site I referenced. Please refer to the Active Cases in Sweden graph. On May 12, there were 18,988 active cases.

          So, what is bothering you?

  6. “Is there a rigorous way to evaluate my defense factor? That is something I would like to see researchers working on. If I knew for sure that I have a strong defense factor, then I could be a lot more relaxed about resuming some of my favorite activities.

    I think this is the heart of the closer argument. As you note in today’s general update, “openers” wish to achieve herd immunity sooner, while “closers” wish to achieve herd immunity later. (This isn’t quite right, I think, but it’s a useful framing*). Isn’t the best closer argument that we need herd immunity later precisely because we need time to research and understand with real clarity who is safe, who is not, why, and when? Today, we have some headline-grabbing guesses, but no real understanding yet. We need to buy time.

    (* To this framing, I would add that closers may believe that we are headed for economic change, not economic ruin. Yes, many businesses will go bankrupt, if we let them (and we should). That is precisely because, in Hayekian terms, the market is sending information which tells us that for the foreseeable future we will need fewer restaurants and more delivery services; fewer retail jobs and more contact tracers. An openness to this sort of change used to be the strength of our economy, though sadly it doesn’t seem to be anymore).

Comments are closed.