During the Great Depression, as he saw ordinary people’s purchasing power collapse, Federal Reserve Chairman Marriner Eccles warned that excessive saving by the rich was draining demand and deepening the downturn. “To protect them from the results of their own folly,” Eccles told the Senate in 1933 testimony, “we should take from them a sufficient amount of their surplus to enable consumers to consume and business to operate at a profit.” Inequality in the US was then extremely high: The top 1 percent held roughly 42 percent of all wealth. Within a decade, however, the landscape changed dramatically. World War II mobilization and progressive taxation reduced inequality and restored balance between spending and production. The underlying problem that Eccles emphasized faded from public memory as the US economy entered a long period of sustained and more equitable growth. […]