"Problem" is that I'm Swedish and thus live in Sweden. Becoming rich here is almost impossible, just as it is impossible to be poor.
So, what are the geographic constraints for becoming rich? I guess it boils down to the US?
Rank Nation Number of billionaires Population People/Billionaire (rounded)
1 Germany 54 82,210,000 1,522,407
2 Russia 32 141,950,000 4,404,687
3 UK 27 60,587,300 2,243,974
4 Turkey 13 71,517,100 5,501,315
5 Italy 12 59,337,888 4,944,824
6 Spain 12 46,157,822 3,846,485
7 France 10 64,473,140 6,447,314
8 Sweden 9 9,234,209 1,026,015
Sources:
http://en.wikipedia.org/wiki/List_of_countries_by_the_number...
http://en.wikipedia.org/wiki/List_of_European_countries_by_p...
Edit: For comparison, I calculated the ratio for the USA (population 306,798,000, billionaires 859, according to the Wikipedia), and found that about one in 357,147 US citizens is a billionaire. So while it's appearantly relatively easy to become a billionaire in Sweden compared to the other European countries, it seems to be even easier in the US. I guess that means you're about half right...
Note2: Since I'm already here for that comment, the number of billionaires is not a very good measure of how easy it is to become rich. "Becoming rich" means moving from middle class to, say, millionaire status. So the metric would be around income changes at that level, not how many super rich people decide to live somewhere or another.
I'd even suggest that "geographic constraints" is thinking it wrong, if you re-read Dennis, or look at actual facts. Discarding the formality of money accounts, there were "rich people" in Stalin's USSR and Mao's China. The degree of unpleasantness of the process varies, of course.