 The Pew Economic Mobility Project's research shows that forty percent of children in the lowest income quintile remain there as adults, and 70 percent remain below the middle quintile, meaning 30% moved up two quintiles or more in one generation.In recent years several large studies have found that vertical inter-generational mobility is lower in the United States than in most developed countries.A 1996 paper by Daniel P. McMurrer, Isabel V. Sawhill found "mobility rates seem to be quite similar across countries."