http://en.wikipedia.org/wiki/Socio-economic_mobility_in_the_United_States#Comparisons_with_other_countries
Several large studies of mobility in developed countries in recent years have found that [b[the US among the lowest in mobility. One study (Do Poor Children Become Poor Adults?"
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.
According to journalist Jason DeParle
At least five large studies in recent years have found the United States to be less mobile than comparable nations. A project led by Markus Jantti, an economist at a Swedish university, found that 42 percent of American men raised in the bottom fifth of incomes stay there as adults. That shows a level of persistent disadvantage much higher than in Denmark (25 percent) and Britain (30 percent) a country famous for its class constraints. Meanwhile, just 8 percent of American men at the bottom rose to the top fifth. That compares with 12 percent of the British and 14 percent of the Danes. Despite frequent references to the United States as a classless society, about 62 percent of Americans (male and female) raised in the top fifth of incomes stay in the top two-fifths, according to research by the Economic Mobility Project of the Pew Charitable Trusts. Similarly, 65 percent born in the bottom fifth stay in the bottom two-fifths.