There are some interesting statistics here.  The part I’ve reprinted says it all.

Social Pressure to Marry Is Dead – Opinion – PatriotPost.US

The failure to marry on the part of the lower and lower-middle classes, not the tax code, Wall Street or competition from China, is what is aggravating inequality in America.

The toll is incalculable. In every way that social science can measure — school performance, drug abuse, unemployment, suicide, poverty, depression, dependence on government handouts, mental illness, violence, and far more — children raised by single parents (especially when their parents never married) are at a severe disadvantage. The failure to form families is devastating our schools, exacerbating inequality and diminishing happiness on a grand scale.