In For Better or For Worse: Entrepreneurs, Families, and Inequality, Arnold Kling argues that “marital choices interact with trends in entrepreneurship to tend to increase inequality of income”:
Since World War II, our economy has evolved in ways that reinforce the financial differences between strong families and weak families. As the earnings of women have risen, “assortive mating” (men and women of similar educational levels tending to marry) tends to widen income differences. The surge in entrepreneurship further rewards strong families. Finally, the rise in divorce and single motherhood puts severe stress on the lower part of the income distribution.