Sources for union membership: OECD (for crossnational comparisons, 1960-2013); Union Source Book and Labour Canada (1920-1955), as cited in W. Craig Riddell, “Unionization in Canada and the United States,” in Small Differences That Matter: Labor Markets and Income Maintenance in Canada and the United States, ed. David Card and Richard B. Freeman (Chicago, IL: University of Chicago Press, 1993).

Source for wealth shares: data from Emmanuel Saez and Gabriel Zucman, “Wealth Inequality in the United States since 1913: Evidence from Capitalized Income Tax Data,” Quarterly Journal of Economics 131, no. 2 (May 2016): 519-78. Wealth shares were estimated by capitalizing income-tax returns.

Note: Click on the chart for the data and an interactive display.

Last updated: 6/12/2017