Eyal Frank (the guy behind the vultures paper) also has a paper finding pretty large effects from decreasing bat populations on infant mortality in the same vein- the channel here is that the bats eat insects that otherwise farmers use insecticide to treat, and the insecticide causes infant mortality (he doesn’t say how but I think it’s birth defects?). He also has one on killing sparrows leading to the Great Famine in China, but the solution to that problem is “don’t put Mao in charge of your economy” which doesn’t seem very relevant in a modern context.
I took a gander at looking into the vultures paper and my first impression is that their methodology isn’t unreasonable, but I wouldn’t expect the effects to be as big in other contexts. For one, a lot of the carrion in India apparently comes from cows, which are treated differently because of their status in Hindu religion and so are more likely to die naturally and less likely to be slaughtered. Plus, the mechanism they hypothesize is that dead animals end up in the water instead of being eaten by vultures, and so the effects would only hold up a) where water contamination is a major portion of the disease burden and b) where those animals can easily end up in the water instead of being eaten by vultures.
If people are interested, I might look into this further and write something up, but I’m not an expert on this and so far everything I saw looked like defensible choices.
Also, on the topic of econ papers with much bigger effects than I was expecting: a very simple savings exercise gives maize farmers in Zambia ~1 month more of expenses to use during the hungry season, and this lets them then have a better harvest the next year.
Eyal Frank (the guy behind the vultures paper) also has a paper finding pretty large effects from decreasing bat populations on infant mortality in the same vein- the channel here is that the bats eat insects that otherwise farmers use insecticide to treat, and the insecticide causes infant mortality (he doesn’t say how but I think it’s birth defects?). He also has one on killing sparrows leading to the Great Famine in China, but the solution to that problem is “don’t put Mao in charge of your economy” which doesn’t seem very relevant in a modern context.
I took a gander at looking into the vultures paper and my first impression is that their methodology isn’t unreasonable, but I wouldn’t expect the effects to be as big in other contexts. For one, a lot of the carrion in India apparently comes from cows, which are treated differently because of their status in Hindu religion and so are more likely to die naturally and less likely to be slaughtered. Plus, the mechanism they hypothesize is that dead animals end up in the water instead of being eaten by vultures, and so the effects would only hold up a) where water contamination is a major portion of the disease burden and b) where those animals can easily end up in the water instead of being eaten by vultures.
If people are interested, I might look into this further and write something up, but I’m not an expert on this and so far everything I saw looked like defensible choices.
Also, on the topic of econ papers with much bigger effects than I was expecting: a very simple savings exercise gives maize farmers in Zambia ~1 month more of expenses to use during the hungry season, and this lets them then have a better harvest the next year.