Part of the problem is that there’s nowhere you can actually donate $50k and prevent or cure 1k cases of blindness. The only [1] EA recommendation in this area is Hellen Keller International (recommended by GiveWell), but looking at their vision benefits writeup and BOTEC, linked from their cost-effectiveness model most of the supplementation is going to people who wouldn’t otherwise become blind. Yes, it’s two pills for ~$2.70, but interpreting GW’s rough estimate is that only 1:1,100 people who get the pill would otherwise become blind. [2] So about $3k to prevent a case of blindness via vitamin A supplementation.
(Note that vitamin A is unlikely to be the cheapest option, since the mortality benefits are the main reason GW has been working on evaluating it, so this is not an estimate of the cheapest way to avert blindness.)
[1] You might also think that Sightsavers would have something to do with vision, but GiveWell’s review is specifically for their deworming program.
[2] 1.3% fraction of kids with night blindness, 10% of those progress to full blindness, relative risk of night blindness post vitamin A supplementation is 32%. Combining these (1/(1.3% * 10% * (1-32%)) gives me 1,100x.
This is tangential to your point, but I don’t think using the “prevent blindness in poor countries vs train guide dogs” comparison they way you’re doing it is a great idea; more here: Fact checking comparison between trachoma surgeries and guide dogs.
Part of the problem is that there’s nowhere you can actually donate $50k and prevent or cure 1k cases of blindness. The only [1] EA recommendation in this area is Hellen Keller International (recommended by GiveWell), but looking at their vision benefits writeup and BOTEC, linked from their cost-effectiveness model most of the supplementation is going to people who wouldn’t otherwise become blind. Yes, it’s two pills for ~$2.70, but interpreting GW’s rough estimate is that only 1:1,100 people who get the pill would otherwise become blind. [2] So about $3k to prevent a case of blindness via vitamin A supplementation.
(Note that vitamin A is unlikely to be the cheapest option, since the mortality benefits are the main reason GW has been working on evaluating it, so this is not an estimate of the cheapest way to avert blindness.)
[1] You might also think that Sightsavers would have something to do with vision, but GiveWell’s review is specifically for their deworming program.
[2] 1.3% fraction of kids with night blindness, 10% of those progress to full blindness, relative risk of night blindness post vitamin A supplementation is 32%. Combining these (1/(1.3% * 10% * (1-32%)) gives me 1,100x.
Thanks Jeff,
It’s helpful to have the facts. I will look for a better example next time!
Cheers
Denis