"One-third of children in the United States are born to unmarried parents. A substantial number of black and Hispanic children live with a never-married mother. Children of never-married mothers are more likely to drop out of high school, repeat grades, and have behavioral problems than are...

"Mexican immigrants were historically clustered in a few cities, mainly in California and Texas. During the past 15 years, however, arrivals from Mexico established sizeable immigrant communities in many "new" cities. We explore the causes and consequences of the widening geographic diffusion of...