Among two-parent families, median earnings did rise by an inflation-adjusted 23% from 1975 to 2009. But the parents’ combined hours worked increased by 26% during the same period–accounting for most of the income gains.
Via Tyler Cowen.
Demographics other than two parent families (including single parents) in many cases saw hourly income declines. The two parent case also conceals declining income for men matched by rising income for women.