This is interesting and definitely updates me a bit, but like others I’m still not convinced.
One thing I think Huw alludes to, but nobody else have spelled out, is considering net effects on other economic sectors than the ones directly studied. (In economics language, “consider general equilibrium more broadl”y). You say:
If the supply of doctors and nurses is fixed, this is a valid concern. In the real world, the supply of doctors isn’t fixed. When people have the option to earn qualifications in order to go abroad and earn more, they are much more likely to pursue those qualifications. When doctors can go abroad (and earn more), more people want to become doctors. Some of these additional doctors will end up leaving, but some will end up deciding not to.2
This is exactly what happened in the Philippines when US visa rules changed to make it easier to move there as a nurse. Many more Filipinos decided to train as nurses; new nursing colleges opened to accommodate the demand. Many of the newly trained nurses did end up moving, but not (even close to) the majority. Even after some left for the US, the Philippines ended up with considerably more nurses than they’d had before.
The same happened in the IT sector in India. Many people in India went to school and learned IT because they hoped to migrate to the US. But not all ended up getting visas to the US—and those that stayed behind helped start the Indian software boom. India did not end up worse off because people tried to migrate; instead, they ended up with more skilled people than ever before.
Imagine a simple model/story where there’s unidimensional STEM competency, call it s. In such a world, perhaps what happens is that some countries with a good fit for a sector (for sake of argument, IT in India, nurses in the Philipines) would have many people in the 99th percentile in s enter that sector without emigration. If emigration via that sector then becomes popular, perhaps 95th-99th percentile people will all enter that sector. Then when the 99th percentile leaves, the remaining people in the 95th-98th percentile people will still buttress the sector (average quality goes down but the effects on that sector are muted because the overall quantity of qualified people goes up).
However, this masks the effect where other sectors are indirectly affected by brain drain to the exporting sector. (In such a world, perhaps the counterfactual without exports would be that India would have great nurses, or the Philipines would have a tech boom).
So you can’t necessarily infer from a specific sector not suffering that the overall counterfactual effects of emigration are net positive.
I think this is a bit of a roundabout argument. From the Philippines study:
We examine the effects of the policy changes on enrollment and graduation in other degree programs to determine whether increased migration prospects for nurses spurred new students to obtain postsecondary education or, instead, caused students to shift from other fields of study. While these results are relatively imprecise, they suggest that nursing enrollees primarily switched to nursing from other fields. This result helps to explain our large enrollment effects by clarifying that we are not estimating the elasticity of overall education to migration opportunities. Rather, the policy changes examined here were occupation specific, and individuals might be more elastic in switching between fields of study than making the extensive margin decision to enroll in higher education… While the enrollment effects were driven primarily by students switching from other degree types, students persisted to graduation at higher rates, leading to an overall increase in college graduates in the Philippines.
So they are finding exactly what you suggest, that people switch to the sector from other sectors, but they also find that if people hadn’t moved, they would have been less likely to graduate college, period. So if you see increases in the overall stock of college workers as an overall positive effect, the program did have an overall positive effect.
But in general, I don’t even think you need to appeal to that kind of reasoning, because brain drain is usually in jobs that are among the most valuable possible jobs for the country. (This is likely because those jobs are both the jobs that rich countries want to import, and also because they must be well-paid for the people to have the means to emigrate.) Medical workers are extremely valuable, so are engineers. It seems a little contrived to imagine that the sectors that lost out were comparably socially valuable.
This is interesting and definitely updates me a bit, but like others I’m still not convinced.
One thing I think Huw alludes to, but nobody else have spelled out, is considering net effects on other economic sectors than the ones directly studied. (In economics language, “consider general equilibrium more broadl”y). You say:
Imagine a simple model/story where there’s unidimensional STEM competency, call it s. In such a world, perhaps what happens is that some countries with a good fit for a sector (for sake of argument, IT in India, nurses in the Philipines) would have many people in the 99th percentile in s enter that sector without emigration. If emigration via that sector then becomes popular, perhaps 95th-99th percentile people will all enter that sector. Then when the 99th percentile leaves, the remaining people in the 95th-98th percentile people will still buttress the sector (average quality goes down but the effects on that sector are muted because the overall quantity of qualified people goes up).
However, this masks the effect where other sectors are indirectly affected by brain drain to the exporting sector. (In such a world, perhaps the counterfactual without exports would be that India would have great nurses, or the Philipines would have a tech boom).
So you can’t necessarily infer from a specific sector not suffering that the overall counterfactual effects of emigration are net positive.
I think this is a bit of a roundabout argument. From the Philippines study:
So they are finding exactly what you suggest, that people switch to the sector from other sectors, but they also find that if people hadn’t moved, they would have been less likely to graduate college, period. So if you see increases in the overall stock of college workers as an overall positive effect, the program did have an overall positive effect.
But in general, I don’t even think you need to appeal to that kind of reasoning, because brain drain is usually in jobs that are among the most valuable possible jobs for the country. (This is likely because those jobs are both the jobs that rich countries want to import, and also because they must be well-paid for the people to have the means to emigrate.) Medical workers are extremely valuable, so are engineers. It seems a little contrived to imagine that the sectors that lost out were comparably socially valuable.