Thanks Aaron for this comment, and the longer one you made elsewhere.
On the excerpt, I think there’s anecdotal evidence for bullet points 1-3 in a few places. GiveWell mention this in an old blogpost about people not buying subsidised nets:
Two different people told us in off-the-record conversations that they thought that this occurred because the mothers offered subsidized bednets believed that they would be able to acquire free nets at some other point. There have been periodic free ITN distributions in many sub-Saharan African countries over the last decade, and the international consensus seems to be that governments should distribute ITNs free of charge in malaria-endemic areas. Accordingly, it should not be especially surprising that citizens may expect bednets to be provided free of charge, and may not move to purchase them even if they are available at subsidized prices in the marketplace. If we reasonably expect to be given something for free in a relatively short time window, why buy it now?
If this happens in a minority of locations, we may just accept that’s the cost of doing business. In order to do a large amount of good overall we accept we’re going to do a small amount of harm. If it happens in a large number of locations, the harm is increased.
Agree with the logic of your last bullet above, though I don’t know the difference in difference in impact between 20% coverage and 80% coverage. It isn’t necessarily linear—could be better or worse than that—and from memory the RCTs here all had universal coverage so no insight from there.
In terms of other stories where distributions may be net negative, I outlined a few in the comments recently. For citizens, workers, business owners and governments there may be wider impacts beyond the market-demand-for-nets idea you’ve described above. How important you think those ideas are probably depends on how you think the economy really works and what might promote or prevent future growth.
Agree a simple calculation as outlined wouldn’t be hard. That would effectively increase the cost-per-life-saved by 20%, say, which is noteworthy but not fundamentally changing things.
The real risk is the longer-term, hard-to-measure impacts which may hold back economic progress generally. These are by definition hard to fit in to a cost-per-life saved calculation but that doesn’t mean the impacts don’t exist. Knowing these risks exist and intervening anyway is a choice some donors will be comfortable with but others will not.