While not comprehensively covered, GiveWell mentions this in a few places. The second point here links to a report with this section discussing whether people are willing to pay for nets, as well as a link to this old blog post which briefly makes the argument that people won’t buy their own nets, since previous hand-outs (from other charities) have resulted in a lack of local producers and an expectation of free nets. They also mention that nets have some positive externalities, and mostly benefits children, who aren’t the ones paying, which gives some reason to subsidize them.
After brief reading, seems like the conclusion is: “At market prices, most people would not use the anti-malaria nets; this is empirically verified. Therefore, we provide the nets for free, and we give the nets instead of cash to buy the nets.”
The obvious question is why are people unwilling to buy the nets?
Is there a rational reason, such as “the money is needed to prevent more immediate dangers, such as starvation”? Or is it an irrational one, such as underestimating the danger of malaria, not understanding how malaria spreads, or fatalism about diseases?
Between rational and irrational is PD: individually rational, collectively irrational. Lanrian gave two reasons that nets benefit people other than they person paying. One is that they are most valuable for children. The other is that they protect people not using the nets. Probably the most valuable nets are those deployed on people who already have malaria, to prevent it from spreading to mosquitoes, and thus to more people. (See also Paul Ewald.)
Probably the most valuable nets are those deployed on people who already have malaria, to prevent it from spreading to mosquitoes, and thus to more people
I hadn’t thought about this! I’d be interested in learning more about this. Do you have a suggested place to start reading or more search term suggestions (on top of Ewald)?
Parasites in general and malaria in particular are pretty specific. For example, humans developed immunity shortly after speciation from chimps and malaria only jumped back 30kya (but probably did so multiple times to produce the several species of malaria). It’s pretty clear that it doesn’t have other hosts in the New World because the strategy of treating all humans in an area for 3 weeks wipes it out. But it’s hard to rule out the possibility that it has other hosts in Africa.
Ewald has written lots of great papers. Here is a paper summarizing his career. Mostly it’s about explaining the past, but he goes on to say that we should design interventions to shape the evolution of infectious agents. His main claim about the past is that malaria is debilitating because it can be passed on from someone who can’t move. Thus if we keep the mosquitoes out of beds or out of homes, then malaria will evolve to be less debilitating. But I’m not sure where he says this. Scientific American? TED?
Thanks! The info on parasite specificity/history of malaria is really useful.
I wonder if you know of anything specifically about the relative cost-effectiveness of nets for infected people vs uninfected people? No worries if not
I don’t know. My claim was based on reasoning from first principles. It was intended as an illustrative example that there could be positive externalities, not to measure them. If you have to triage nets, it’s probably the way to go, but if you’re triaging nets, you’ve probably made a bad decision. I can think of so many reasons to concentrate nets in one village, rather than spreading them out and micro-managing the deployments in the villages. One reason is habit formation. Another is the cost of distribution, which is probably low for marginal nets and high for a new village. A third is that there positive externalities compound, at least if you cross over the threshold of locally wiping out malaria. (Under that threshold, I’m not sure.)
While not comprehensively covered, GiveWell mentions this in a few places. The second point here links to a report with this section discussing whether people are willing to pay for nets, as well as a link to this old blog post which briefly makes the argument that people won’t buy their own nets, since previous hand-outs (from other charities) have resulted in a lack of local producers and an expectation of free nets. They also mention that nets have some positive externalities, and mostly benefits children, who aren’t the ones paying, which gives some reason to subsidize them.
After brief reading, seems like the conclusion is: “At market prices, most people would not use the anti-malaria nets; this is empirically verified. Therefore, we provide the nets for free, and we give the nets instead of cash to buy the nets.”
The obvious question is why are people unwilling to buy the nets?
Is there a rational reason, such as “the money is needed to prevent more immediate dangers, such as starvation”? Or is it an irrational one, such as underestimating the danger of malaria, not understanding how malaria spreads, or fatalism about diseases?
Between rational and irrational is PD: individually rational, collectively irrational. Lanrian gave two reasons that nets benefit people other than they person paying. One is that they are most valuable for children. The other is that they protect people not using the nets. Probably the most valuable nets are those deployed on people who already have malaria, to prevent it from spreading to mosquitoes, and thus to more people. (See also Paul Ewald.)
I hadn’t thought about this! I’d be interested in learning more about this. Do you have a suggested place to start reading or more search term suggestions (on top of Ewald)?
Also, can animals harbour malaria pathogens that harm humans? This section of the wiki page on malaria makes me think not, but it’s not explicitly stated
Parasites in general and malaria in particular are pretty specific. For example, humans developed immunity shortly after speciation from chimps and malaria only jumped back 30kya (but probably did so multiple times to produce the several species of malaria). It’s pretty clear that it doesn’t have other hosts in the New World because the strategy of treating all humans in an area for 3 weeks wipes it out. But it’s hard to rule out the possibility that it has other hosts in Africa.
Ewald has written lots of great papers. Here is a paper summarizing his career. Mostly it’s about explaining the past, but he goes on to say that we should design interventions to shape the evolution of infectious agents. His main claim about the past is that malaria is debilitating because it can be passed on from someone who can’t move. Thus if we keep the mosquitoes out of beds or out of homes, then malaria will evolve to be less debilitating. But I’m not sure where he says this. Scientific American? TED?
Thanks! The info on parasite specificity/history of malaria is really useful.
I wonder if you know of anything specifically about the relative cost-effectiveness of nets for infected people vs uninfected people? No worries if not
I don’t know. My claim was based on reasoning from first principles. It was intended as an illustrative example that there could be positive externalities, not to measure them. If you have to triage nets, it’s probably the way to go, but if you’re triaging nets, you’ve probably made a bad decision. I can think of so many reasons to concentrate nets in one village, rather than spreading them out and micro-managing the deployments in the villages. One reason is habit formation. Another is the cost of distribution, which is probably low for marginal nets and high for a new village. A third is that there positive externalities compound, at least if you cross over the threshold of locally wiping out malaria. (Under that threshold, I’m not sure.)