Pedro Domingos

Which is mainly a problem if you think that everyone has equal talent, and the only cause of differential achievement is discrimination. (BTW, I've lived in the US and two very different European countries, and America is a classless society in a way that Europe will never be.)

We should not worry too much about social mobility unless "*everyone* has equal talent". What kind of argument is this?

I didn't say that. Stop making up straw men. Once you take ability into account, the difference in mobility between the US and European countries largely disappears. Refute that or admit it.

How did you not say that? And why is the burden on me to refute such as silly claim? It is your burden to support your claim. I'm not even sure what your claim is. Is it your claim that the distribution of talent is different in US and Europe?

Outcomes are a function of both ability and opportunity, both of which vary within each country. If you ignore ability, you imagine greater differences of opportunity than are really there. Is that clear now?

Social mobility in the US has gone down precisely because the US is ahead of Europe in matching ability to outcomes, assortative mating, etc. (And Piketty is a joke.)

Or, it could be because inequality has grown so much larger, with the powerful rigging the system in their favor. I'll have to reflect more on that. (And much of Piketty is simply showing historical trends in economics -- you don't like the descriptive stats?).