Times writer Travernise looks at a new study by Stanford University. According to Travernise, "the findings show a changed map of prosperity in the United States over the past four decades, with larger patches of affluence and poverty and a shrinking middle."

The study analyzes the changes in neighborhoods and the growing wealthy suburbs.

"Lawrence Katz, an economist at Harvard, said the evidence for the presumed adverse effects of economic segregation was inconclusive. In a recent study of low-income families randomly assigned the opportunity to move out of concentrated poverty into mixed-income neighborhoods, Professor Katz and his collaborators found large improvements in physical and mental health, but little change in the families' economic and educational fortunes."

"But there is evidence that income differences are having an effect, beyond the context of neighborhood. One example, Professor Reardon said, is a growing gap in standardized test scores between rich and poor children, now 40 percent bigger than it was in 1970. That is double the testing gap between black and white children, he said."

Thanks to Cathie Pagano