A host of social and economic shifts have contributed to the trend toward unequal opportunity. Children who grow up in a home with both of their biological parents are more likely to stay in school, avoid prison, and earn more in adulthood. The share of poorer children who grow up with both parents has fallen in the past several decades, while there has been far less change in family structure for those with higher incomes.
Parenting traits and behaviors have long differed according to parents' education and income, but this difference has increased with the advent of the modern intensive-parenting culture. Low-income parents aren't able to spend as much on goods and services aimed at enriching their children, such as music lessons, travel, and summer camp. Studies show they tend to read less to their children and provide less help with schoolwork. They are less likely to set and enforce clear rules and routines for their children. And they are less likely to encourage their children to aspire to high achievement in school and, later, at work.
Differences in out-of-home care also have widened. A generation ago, most preschool-aged kids stayed at home with their mothers. Now, many are in childcare of one sort or another. Children of affluent parents can attend education-oriented preschools, while kids of poorer parents are more likely to be left with a neighborhood babysitter who parks them in front of the television.
Children from poor backgrounds are less likely than others to enter and complete college, and in the past generation this difference has expanded, due in part to the rising cost of a college degree.
The job market has become more difficult, too. Technological advance, globalization, loss of manufacturing employment, union decline, and other developments have reduced the number of jobs that require limited skills but pay a solid wage – the kind that once moved poorer Americans into the middle class.