We granted Population Services International in our Saving Lives in Africa cause, focusing largely on their condom and bednet distribution and promotion programs. Soon after we cut the check, I got into a conversation with someone who questioned whether bednets are effective at all. He pointed me to a paper, “Combating malaria morbidity and mortality by reducing transmission,” which questions whether bednets are likely to have a long-term impact on malaria mortality.
Bednets reduce the number of bites that people receive from malaria-carrying mosquitoes, which in turn reduces incidence of malaria. This has two effects: (a) it reduces malaria mortality; but (b) it also reduces acquired immunity to malaria. The authors of this paper found, empirically, that areas that had lower rates of bites had similar rates of malaria mortality but a different age distribution of deaths. In places with high bite-rates, malaria mortality was restricted to children; in places with low bite-rates, adults died as well. The authors hypothesize that bednet programs may only shift the age at which people die from malaria, and have no impact on the total number of deaths from malaria.
This doesn’t mean bednets are useless. First of all, the analysis in the paper isn’t general enough to cover every case – there could be population configurations such that protecting people during their weakest years is a net benefit. There could be regions with high enough bite-rates that nets merely reduce the number of bites without affecting immunity. Also, even if total morbidity and mortality don’t change, there is definitely value in people living longer before they die. But, if it’s true that reducing mosquito bites can matter much less over the long term than over the short term, this is important when weighing the value of bednets. This paper really highlights what systematic analysis and measuring can do – and what you can miss by skimping on them.
At the moment, we’re still working on our education cause; bednets are something we’re thinking about, not devoting our time to. But if we revisit the cause of aid to Africa next year, we plan to incorporate this research into our analysis, and possibly change our recommendations. We don’t expect our decisions to be perfect; they’re merely our “best bet” given what we know. Enabling anyone to provide feedback on our grant decisions, which refines (or contradicts) our previous understanding, is precisely why we think a public discussion of what charities do and how well it works is necessary.