EA - Is Nigerian nurse emigration really a "win-win"? Critique of a CGD article by NickLaing

Welcome to The Nonlinear Library, where we use Text-to-Speech software to convert the best writing from the Rationalist and EA communities into audio. This is: Is Nigerian nurse emigration really a "win-win"? Critique of a CGD article, published by NickLaing on June 9, 2024 on The Effective Altruism Forum.
I write to raise what I think is a fundamental flaw in a Center for Global Development (CGD) article about immigration.[1] I posted here only after receiving what I considered inadequate feedback from the authors over the last 3 months.[2]
The major argument of the article "UK recruitment of nurses can be a win-win" is that the current situation where Nigeria exports an ever-increasing number of nurses to the UK could be good for both countries. For Nigeria, the benefits come through both the classic economic benefits of remittances, and stimulating increased nurse training in Nigeria to compensate for the losses of nurses.
A Misleading Datapoint
The central datapoint on which their argument rests seems misleading. The authors cite the number of nurses who leave Nigeria each year for the UK alone and claim that increased nurse training in Nigeria is enough to replace these nurses.
"Between late 2021 and 2022, the number of successful national nursing exam candidates increased by 2,982 - that is, more than enough to replace those who had left for the UK." Technically, they are correct that the number trained replaces those who leave only for the UK, but they don't consider the majority of nurses who left to other countries.
Emigration to the UK constitutes under 25% of the total nurse emigration from Nigeria. A more meaningful data point would have been the total number of nurses that leave Nigeria for all countries. Based on
this Guardian article (and others), about 29,000 new nurses were registered in Nigeria over the last 3 years, while 42,000 left. The total number of nurses in Nigeria is reducing, not increasing as they claim.
To express this situation graphically, the best graph to illustrate whether or not nurse Migration is a "Win-Win" for both Nigeria and England might have looked more like this (forgive the poor formatting!)
Over the last 3 years Nigeria has lost a net 13,500 nurses. This is a loss of about 1% of their nurse workforce a year, while Nigeria needs an increase of around 2.5% nurses yearly just to keep up with population growth. This assumes that no nurses left or joined the Nigerian workforce for other reasons.
Nurses may leave the Nigerian workforce due to retirement or for other work, while nurses could also be entering Nigeria from other countries to work - I doubt these adjustments would make a big difference to the overall analysis.
Based on this data, it looks like England will win and Nigeria will lose. My main claim is that it is incorrect to claim a win-win scenario for two countries when emigration from Nigeria includes a majority of nurses leaving for many other countries - not just the UK. I'm very happy to be shown where I've gone wrong here and welcome any comments!
An Author's response
Privately, one of the authors briefly responded that their argument is based on the change in trainees and migrants over time. This still avoided my concern: you cannot look at migration outflows and inflows between two countries in a vacuum. The author also noted
WHO data
that shows a flat trend in the number of nurses per 1,000 people. I agree that tracking "nurses per capita" over time would be the best way to measure whether the nurse situation in Nigeria is improving or deteriorating. However the world bank data appears grossly inaccurate. Their "nurses per 1,000 population" number fluctuates implausibly between 1.75 per 1,000 in 2016, to almost half that 0.9 per 1,000 in 2018 then back up 1.5 per 1,000 the next year.
Unless 100,000 nurses left Nigeria over 2 years then flooded back in the next year (not the case), the data is absurd and not to be trusted. The most proximate data we have to underst...