when you look at canada. that s right. i think the honest answer is we don t really have a good sense of why countries differ in terms of their mobility rates. miles corak is an economist at the university of ottawa, has done some really interesting research on u.s./canadian differences. what he found is canada does a few things that very clearly are different from american policy, and so at the end of the day he sort of noted that canada has more family leave, more generous policies when for both fathers and mothers when kids are born. it also has very different demographics than the u.s. as well. so the united states has a lot more teen child-bearing, a lot more entrenched poverty. we have a lot of segregation of a lot of our poor population, which i think is a really important result that jumps out in raj s paper. but i don t think we have a really good sense at all of how