The report "Downward Mobility from the Middle Class: Waking Up from the American Dream" shows a third of children raised under middle class conditions fell out of the middle class as adults.
The report comes from the Pew Charitable Trusts. In the introduction, researchers cite a popular definition of the American Dream - your children are financially better off than you.
For varying reasons, the dream didn't work out for one third of the people they looked at.
The report used data from the 1979 National Longitudinal Survey of Youth. 12,686 young men and women who were 14-22 years old were part of that survey.
The reports authors define middle class as being "those falling between the 30th and 70th percentiles of the family-size-adjusted income distribution." Or a family with two adults and two kids making between $32,900 to $64,000 (in 2010 dollars).
Author Gregory Acs writes that while the chances of falling out of the middle class reflects what one might expect mathematically, "not all middle-class children are equally likely to fall."