Yes, because he did study in the US, at the University of Pennsylvania (http://en.wikipedia.org/wiki/Elon_Musk#Early_life). Granted he had a scholarship, but people like Elon Musk tend to get scholarships. For regular Americans state schools are affordable w/ government loans.
> The science says that social mobility is much higher in other countries like Denmark than in the US
No offence to Denmark but I can't imagine that many immigrants chose to immigrate there instead of the US because of social mobility scores.
By definition most immigrants are ambitious, or at least willing to risk leaving their country of birth for the possibility of greater opportunities elsewhere.
Countries with a high immigrant population in the preceding generation score very high - just because the first wave of immigrants probably did relatively badly compared to the average population, so if their kids do average that looks like high mobility
The science says that social mobility is much higher in other countries like Denmark than in the US:
> Several studies have been made comparing social mobility between developed countries. One such study (“Do Poor Children Become Poor Adults?")[5][15][16] found that of nine developed countries, the United States and United Kingdom had the lowest intergenerational vertical social mobility with about half of the advantages of having a parent with a high income passed on to the next generation. The four countries with the lowest "intergenerational income elasticity", i.e. the highest social mobility, were Denmark, Norway, Finland, and Canada with less than 20% of advantages of having a high income parent passed on to their children.
-- http://en.wikipedia.org/wiki/Social_mobility#Country_compari...