https://www.google.com/amp/s/prospect.org/api/amp/power/libertarian-delusion/
A third grotesque case of market failure is the income distribution. In the period between about 1935 and 1980, America became steadily more equal. This just happened to be the period of our most sustained economic growth. In that era, more than two-thirds of all the income gains were captured by the bottom 90 percent, and the bottom half actually gained income at a slightly higher rate than the top half. By contrast, in the period between 1997 and 2012, the top 10 percent captured more than 100 percent of all the income gains. The bottom 90 percent lost an average of nearly $3,000 per household. The reason for this drastic disjuncture is that in the earlier period, public policy anchored in a solid popular politics kept the market in check. Strong labor institutions made sure working families captured their share of productivity gains. Regulations limited monopolies. Government played a far more direct role in the economy via public investment, which in turn stimulated innovation. The financial part of the economy was well controlled. All of this meant more income for the middle and the bottom and less rapacity at the top.
Clearly, a more equal economy performed better than a more unequal one. Families with decent incomes could recycle that purchasing power back into the economy. Well-regulated financial institutions could do their job of supplying investment capital to the real economy rather than enriching their own executives with speculative schemes-ones that left the rest of the society to take the loss when the wise guys were long gone. In the case of labor, there was not a single, "accurate," market-determined wage for each job, but a wide range of possible wages and social bargains that would attract competent workers and steadily increase the economy's productivity.