Jens 'n' Frens

Some miscellaneous thoughts related to herd immunity, especially as it relates to covid.

I'm writing this on a morning on which nobody believes the withdrawal of US forces from Afghanistan was executed well, and some of the opponents of withdrawal are stealing some bases. I consider both pro-withdrawal and anti-withdrawal to be reasonable, arguable positions, and I don't intend here to be arguing against withdrawal per se, but I'm arguing against a particular argument for it.

For the last few years, our deployment to Afghanistan was small, and the number of casualties very low. That seemed to be sufficient to hold things stable in terms of denying terrorists most of the country, protecting most of its citizens from their depravities, sustaining for the United States military and intelligence an outpost in an important part of the world, and so on. Let's suppose that leaving that contingent in place for another three months would bring us those benefits for another three months, with no other changes in the situation; we then should ask whether those benefits are worth those costs. What I often see instead is people seeming to argue that these costs count as costs, but these benefits don't count as benefits, and that the only reason to keep any presence there is if it can buy us benefits that are longer lasting than the costs.

This has the feel of the idiotic but pervasive framing of renting a house as "throwing money away", which gets the whole housing thing exactly backward. Indeed, the complication with any investment, including housing (or "residential fixed investment", as it is called in the national accounts), is that you have to compare a "stock" — a cost incurred "at once", or in practice over a short period of time — with a "flow", the continued benefit from it over a long period of time. Buying a house presents this trickier problem, where renting does not; the running benefit can be matched up with the running cost. Indeed, a useful way to think of buying a house is to imagine that you are prepaying that portion of the future rents that would not go to running expenses, e.g. maintenance, insurance, and property taxes. If you buy a house, I encourage you to estimate the future rent you are effectively paying, perhaps using the (somewhat-recently paywalled) New York Times renting-versus-buying calculator; if you put in reasonable assumptions, the effective rent will certainly be positive, and will typically be comparable to the rents of similar housing.[1][2]

There are certainly times — in foreign policy and adjacent fields as anywhere else — when stocks have to be compared to flows. To the extent the premises I presented are correct, this isn't one of those times; we have the simpler choice of comparing flows with flows. What would we buy by having troops there for another five years? We would buy another five years of the status quo. How long should we leave the troops there? For as long as it offers a higher benefit than the cost.

Now, I do suspect that something would change over time, and indeed that having troops there would effect some kind of change, though I don't know whether that would be good or bad. I'm more inclined than I was a month ago to think that the cost of maintaining the status quo would have gone up if the Taliban hadn't anticipated our departure at some point soon. There is probably some change in stock that needs to be taken into account here. What I find remarkable, and frustrating, is the denial of what seems to me to be the more obvious part of the equation: the primary benefit was the ongoing benefit, which was substantial.

This post was going to start with a discussion of prescriptivism versus descriptivism and semantics in general, but that's a different essay (which I intend to write, but not soon) and felt like throat-clearing in this context. Today I want to note a few words that I see used in ways that lack a nuance that I think the words ought, in some sense, to have. I'm not a hard-core adherent to the Sapir-Whorf hypothesis, but I worry that people using these words too generally in some cases inculcate the conflation of importantly different ideas. (Perhaps ironically, in two of the cases I will treat verb and noun forms of the words together, not really bothering to distinguish between them.)

The following two words are different from the preceding three, in that I don't believe that the words do make a distinction when used as I perceive "correctly", but I want to note that they take in very diverse concepts that deserve a distinction, with the same Sapir-Whorf risks of conflation.

Suppose that it is agreed that it is within the proper authority of government under current circumstances to place substantial restrictions on people in order to curb the contagion of disease. The purpose isn't --- or certainly shouldn't be --- to torment people, to destroy society, to ruin businesses. The purpose should be to curb contagion and, in particular, hospitalizations and death. Accordingly, if there are large classes of activities that present very low risk of creating contagion, those should be allowed. I think historically the cultural right in particular has recognized arguments like "it's not fair that you're clamping down on high-cost activities but not low-cost activities" as nonsense; indeed, clamping down on low-cost activities in the name of "fairness" is closer to petty vindictiveness than it is to fairness.

This is true of activities, but is also true of people, and there some things do get trickier. When a couple of people come into the country with ebola, we isolate those people, while everyone else largely goes about their business. It makes no sense to restrict people who are known not to be carriers of any disease; what is trickier is when we don't know who is spreading the disease. A fuller test-and-trace system would have allowed better-targeted restrictions; if you can restrict 5% of the population and thereby 90% of carriers of the disease you have to do little else to keep the infection rate down. Perhaps test-and-trace would have worked better with higher state capacity, but I have the impression there was also a fair amount of resistance to it by a lot of the population that was worried about privacy. I feel like we've given up a lot more private control of our lives than we would have if test-and-trace had been effective.

So now we get to talk about "vaccine passports". Some people arguing for a vaccine passport system talk actively as though they want to punish people who choose not to get the vaccine; many more people argue for it as an incentive for people to get the vaccine, which seems less execrable but still to the side of the main point. As evidence accrues that people who are fully vaccinated spread the disease far less than people who aren't, it is simply the case that, at certain levels of case counts, some activities are quite risky (to themselves but also to others) when carried out by some people than when carried out by others. If there are restrictions that make sense, but are unnecessary for people who are vaccinated, it makes sense to make that discrimination.

I have heard a suggestion that it is too early to talk about vaccine passports; this assertion seems to come from the idea that the sole purpose of the passports is to incentivize getting vaccinated, and the observation that demand still exceeds supply. In fact, because I reject that as a particularly good motive for vaccine passports, I think the window of time in which they make sense is in fact likely to close within a couple of months; once case numbers nationally are down below 10,000 per day, things should basically be open regardless of who has been vaccinated, and I'm hopeful that herd immunity will get us there by the end of the summer. The reason to be especially skeptical of vaccine passports now, then, is the permanence of government programs; especially if they are required by governments to engage in various activities, it seems optimistic to think that the restrictions (and privacy costs) will be as curtailed in time as they should be.

Ultimately, in principle, it seems very likely to me that there's a setting in which a bad team that brings in little revenue directly, in a good league brining in a lot of revenue collectively, might be worth more than a good team bringing in more revenue directly but in a league that brings in comparatively little revenue collectively.