I'd be more interested in a study of how people move from lower classes to at least upper middle class.
So you have a good question is all I'm trying to say.
#1 was born to a teenage mom (and an alcoholic/deadbeat dad). Since she was still in high school, I assume she was probably in the bottom quintile of income.
#7 was given up by his mother and adopted.
#9 was born in the Soviet Union. It's likely his family's income (in rubles) was in the bottom quintile of the United States at the time. (Sources I've found suggest that the top 1% income cutoff in the SU was around 250 rubles per month, which is less than the $5,000--$7,500 cutoff for the bottom quintile in the US at the time.)
#13 was born in Yemen before his family moved backed to India. One could probably assume that he was in the bottom quintile by US standards, because even today, the top 10% cutoff in India is below the bottom 10% in the United States.
#18 was born in China and I have little doubt that he was far below the bottom quintile cutoff for the United States growing up.
You might think it's a stretch to call Bezos's family "bottom quintile", but saying that billionaires Zhong Shanshan, Xu Jiayin, or Qin Yinglin weren't is hard.
Also, people born in foreign countries had completely different experiences, and more importantly, what is relevant is if they were in the bottom quintile in their own country.
If you're super rich in your own country then you have a lot of opportunity. For example Sergey Brin may have been born in Russia, but his family managed to come to the US when he was a kid and he was clearly middle class as a teen.
I think the comment does refer to Jeff Bezos. Here is the relevant section from Wikipedia:
"At the time of his birth, his mother was a 17-year-old high school student and his father was 19.[17] After completing high school despite challenging conditions, Jacklyn attended night school while bringing baby Jeff along.[18]"
IMO a 17 year old attending night school is pretty low in terms of economic status.
Also I am sure there are other cases but I know about #17 (Mukesh Ambani) and his father was a petrol bunk attendant - pretty low down even by Indian standards.
And https://en.wikipedia.org/wiki/Zhong_Shanshan "He dropped out of elementary school during the Cultural Revolution and found work in construction."
https://en.wikipedia.org/wiki/Xu_Jiayin "Xu Jiayin was born to a rural family in Jutaigang Village, ... His father is a retired soldier who participated in the Second Sino-Japanese War in the 1930s and 1940s. After the establishment of the Communist State, he became a warehouseman in his home-village. Xu's mother died of sepsis when he was 8 months old. He was raised by his paternal grandmother. After high school, he worked in a cement product factory for a few days and then worked for two years at home."
https://en.wikipedia.org/wiki/Qin_Yinglin "Qin was born in 1965 in Hexi Village... He grew up in poverty.
In 1982, when Qin was in high school, his father saved up money and bought 20 pigs, but all but one died. This motivated Qin to study pig farming at university, so that he could help people in his village earn money raising pigs."
I'm not sure billionaires like Eric Yuan ("collected construction scraps to recycle copper for cash"), Jay Chaudhry ("Chaudhry was born in Panoh, a Himalayan village without running water"), Jan Koum ("When he was living on welfare, Jan Koum's family collected food stamps a couple of blocks"), Isaac Perlmutter ("He emigrated to America, arriving in New York City with only $250"), and Romesh Wadhwani ("He contracted polio at age of 2") count as "super rich in your own country" that would thus "have a lot of opportunity".
At the time of Mukesh Ambani's birth, his father was in Aden colony (present-day Yemen). A year later, he supposedly left:
> The rise of Ambani began in 1958 when he gave up his clerical job in Aden and moved back to Mumbai with fifty thousand rupees in his pocket. https://knappily.com/onthisday/dhirubhai-ambani-death-legacy...
If the claim is to be believed, then 50000 rupees of wealth is probably the lowest quintile in the United States (at the time).
Of course, Dhirubhai Ambani is probably a better example himself, but he is dead.
Elon's "teenage mother" was a famous model.
Here's a chart that tries to show the decline of upward mobility in the U.S. with an article that explains it. While, from the reading I did while trying to find this - which was not a huge amount - it does appear down, somewhat, worldwide, it is in a much sharper decline in the U.S. on average. This, of course, is in comparison to European nations. Not a true "worldwide" comparison.
Also I like the stagnant wage growth numbers because it demonstrates that the corporations are no longer the gatekeepers to economic opportunity. If you're more likely to make money starting a business than getting a job somewhere and working there 30 years, this is good for everyone because their economic prospects aren't dictated by McDonalds and General Motors. It means a more diversified economy, more opportunity beyond the beaten path, and more creativity driving economic growth.
I'd also like to see the criteria for "upper", " middle" and "lower" used in the chart about income distribution. Judging by the first graph of "is it all bad news?" I'd say it's a hard dollar amount delimitation, a very bad metric, because while that would appear to show a bad trend, all it shows is that more people have higher amounts of money. The only way to get a clear picture is to weight income/wealth with purchasing power as the delimiter between classes.
Another note on this first graph, it clearly shows that less people are in the lower class and lower middle class, and more people are in the middle, upper middle and wealthy class with each graph since 1967, which means people have gotten richer and as a whole life is getting better for people economically. Ideally what you'd want to see is the bars to the right of each sample get bigger and the bars to the left get smaller with each sample, and you almost see exactly that. I'd like to see the same graphs in 20 years and that will tell if upward mobility has actually decreased. I'd also like to see this graph weighted with purchasing power.
From those graphs, upward mobility looks perfectly fine, I'm getting the sense it peaked about 20-30 years ago, but has not had a sharp decline and is definitely still higher than it was 50 years ago.
The world just went through massive war that destroyed nearly all of Europes infrastructure and the demand to fix it mostly manifested as opportunity for Americans. Since then Europe has rebuilt and both India and China have arrived on the scene as powerhouses of their own. We will never have the same opportunities that we had then again, or at least we should all pray we don't.