Surprisingly, there are some recent, more sophisticated studies indicating that our social mobility is a lot better than earlier thought, relative to the countries that are usually lauded for social mobility.
For example, Scandinavian countries are famous as exemplars for how to be a developed country with high income mobility. But a recent paper focused on Denmark (the most income-mobile country in the group) in order to study the effectiveness of the Scandinavian model. It found that pre-tax, pre-transfer income mobility was the same as the US! Needless to say, this is a pretty shocking find, as it belies years of assumptions about equality of opportunity and its effect on achievement (as measured by income). Even the addition of Denmark's much heavier investment in all levels of schooling does nothing to budge the level of educational attainment among the poor, relative to the US.
From the Atlantic article linked in my footnotes:
> Low-income Danish kids are not much more likely to earn a middle-class wage than their American counterparts. What’s more, the children of non-college graduates in Denmark are about as unlikely to attend college as their American counterparts.
IMO, Denmark's generous redistribution is worth the impact on outcomes, but it's fascinating to see redistribution have almost ZERO impact on one of its most positive-sum, universally appealing benefits (moving more towards equality of opportunity).
[1] http://voxeu.org/article/intergenerational-mobility-denmark-...
[2] http://www.theatlantic.com/business/archive/2016/08/the-amer...