Monday, August 16, 2021 :::
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.
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.
 One reason to buy (or rent) rather than rent (or buy) may well be that different kinds of housing are often available; in may places rental housing is primarily apartments and resident-owned housing is primarily single-family. Usually there are enough single-family homes for rent for at least some notion of what the rental rates are to exist.
 Sometimes you will get lucky, or perhaps have special local knowledge, and, even after accounting for your labor costs in doing any DIY projects, the house price will rise fast enough after the fact for your rent to be, ex post, lower than you expected; sometimes you will get unlucky, as I did with my first home purchase and my parents did with theirs. Neither is to be counted on.
::: posted by dWj at 11:09 AM