Wednesday, April 14, 2021

Follow Decision Theory!

Back in January, I wrote that there's no such thing as "following the science" -- that scientists and medical experts "aren't experts in ethical or rational decision-making. Their expertise merely concerns the descriptive facts, providing the essential inputs to rational decision-making, but not what to do with those inputs."

It's worth additionally emphasizing that this question of how to convert information into rational decisions is not something about which academic experts are entirely at sea. On the contrary, there's a well-developed academic subfield of decision theory which tells us how to balance considerations of risk and reward in a rational manner.  The key concept here is expected value, which involves multiplying (the value of) each possible outcome by its probability.  For example, we know that (all else equal) we should not accept a 50% chance of causing 10 extra deaths for the sake of a 1% chance of averting 100 deaths, for the latter's expected value (one death averted) does not outweigh the former's expected cost (5 extra deaths).

Now, my central complaint throughout the pandemic has been that policy-makers and institutions like the FDA (and their European equivalents) have evidently not been guided by any sort of cost-benefit analysis or the most basic principles of decision theory.  As Govind Persad put it, withholding vaccines during a pandemic is like withdrawing the service ladder from a subway tunnel for a safety check, while someone is stuck in the tunnel.  The tiny risk of harm from the vaccine is completely dwarfed by the risk posed by remaining vulnerable to COVID-19.  Prioritizing the former risk over the latter thus reveals a shocking kind of innumeracy and normative ignorance on the part of these policy-makers.

Trump's flouting of established scientific expertise deplorably caused many unnecessary deaths.  But the same can be said of the broader medical establishment's flouting of normative expertise, which can be every bit as deadly, and should be decried as similarly deplorable.

[The outcry won't happen, of course, because while Trump was low-status (by the Blue Tribe's lights), the medical establishment is high-status.  Members of the liberal intelligentsia can't signal their tribal loyalty by raising such criticisms; quite the opposite -- they might instead sound like [shock horror] libertarians!  Still, it could serve as a pretty good test of intellectual honesty and truth-seeking, so might gain some traction in those rare sub-communities that care more about that sort of thing than about status hierarchies.]

Some have defended the establishment's self-styled "caution" (read: wild recklessness) on the grounds that the "vaccine hesitant" public is so irrational that authorities need to make bad and misleading decisions in order to signal to the public that they take their (irrational) concerns seriously.  The costs of making decisions that are bad on the merits may be outweighed by the indirect gains to their institutional credibility, at least if they're thereby able to "reassure" the public and get more people on board with (eventual) vaccination.

I find this reasoning bizarre on so many levels.  I mean, few people would defend public authorities spreading harmful scientific misinformation (about masks, say) in order to try to "build their credibility" with a deluded and skeptical public.  Spreading harmful misinformation is bad on its face, and seems a dubious strategy for building long-term credibility.  But to pretend that rare side-effects warrant suspending vaccinations is itself a kind of harmful misinformation (this time normative rather than empirical), and by default we should consider its tactical spread to be a bad idea for all the same reasons.  On its face, it seems far more likely to bolster than to assuage vaccine hesitancy, and it undermines the credibility of the authorities when the truth comes out.

(Of course, ultimately, the effects on vaccine hesitancy are an empirical matter, so I'll withdraw this particular objection if it turns out that the authorities were in close consultation with psychologists and sociologists -- the relevant disciplinary experts -- before making their decisions.  But I somehow very much doubt that.)

But even if I'm mistaken about it being counterproductive, it's also morally wrong to deprive innocent people of the means to protect themselves from a lethal virus merely in order to protect fools from self-inflicted risks.

So please, no more excuses.  We should demand that public authorities follow decision theory, and make rational choices using cost-benefit analysis, given the available empirical data.  Anything less is a betrayal of the public trust, of Trumpian proportions.

1 comment:

  1. You write, "...that scientists and medical experts aren't experts in ethical or rational decision-making."

    I'd be particularly interested in reading more from you, and/or links to elsewhere, in a broader focus this topic. To what degree are authorities in science, medicine and philosophy rational?


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