The second time I stayed in Russia in the mid-90s, the host mom once gave her opinion about why America was so rich and why Russia would stay poor: America had attracted the most adventurous, “can-do” people from all over the world, who were willing and able to emigrate, while Russia was left with the “can’t-do” people who had stayed behind.
Whether or not this tells you much about Russia’s problems (or America’s strengths), it seems likely to me that at least some poor countries are being harmed by losing their best and brightest to emigration. For example, let’s take a country like the Republic of the Congo.
As of 2016, the birth rate in the Republic of the Congo is 36 per 1,000, and the death-rate is 10 per 1,000. There is also currently a net emigration rate of 6 per 1,000 each year. Let’s make a couple of assumptions that seem pretty reasonable:
a) Let’s assume that emigration is non-random: if you are 1 standard deviation above the mean for potential for economic success, you have a 1.5 % chance of leaving each year, if you are 2 standard deviations above the mean for economic success you have a 3.0% chance of leaving each year, and so on (this gets us a 6 per 1000 starting emigration rate.) If you are below the starting mean, you don’t leave.
b) Let’s also assume that children grow up to resemble their parents in potential for economic success.
So if we start in 2016 with a normally distributed population of 4,400,000:
Each year, we get 36 births per 1,000 people, and 10 deaths per 1,000 people, and 6 net emigrations per 1,000 people. If the births and deaths are random, after 30 years we have a population of a little over 8 million, which has shifted to the left on our “potential for economic success” characteristic:
Even though the mean has shifted only 0.2 standard deviations to the left, the % of the population that exceeds certain benchmarks has dropped considerably: there are only 58% as many people who exceed 1 standard deviation above the starting mean, 38% as many who exceed 2 standard deviations, and less than 25% as many who exceed 3 standard deviations as before the 30 years. This obviously influences the percentage of the population who can become competent government workers, or doctors or teachers or college professors or engineers.
You think of open borders and free movement of people as making different parts of the world more similar to each other, and in some ways this is no doubt the case, but those processes can also intensify differences, making poor places poorer and making certain global cities into the kind of place that attracts “people who would just as soon step on your face as look at you,” as they say about New York in Ghostbusters 2.
There’s probably a similar process happening in rural India as more people have left for the city, and in why shrinking cities like East St. Louis, Illinois or Camden, New Jersey tend to have more ever more entrenched problems as their populations collapse.