He asks, "Where in the world is it easiest to get rich?" Where could he have been born and become rich the easiest.
His professor says that he needed to have been born in a society with free markets, low taxes and minimal government intervention.
So, his measurement is based on the number of rich people per capita.
His argument seems to be that government paid higher education makes it easier to get rich and lower paying jobs appear to have been eliminated through the use of technology.
Beyond that, there's not much else presented.
If he controlled for immigration into Denmark versus the United States, his results might not be as easy for him to conclude.