For those who are interested, here are the data sources for the Oct. 20th piece.
For part 2, "The New Gilded Age": The standard source for data on growing inequality is the Census "historical income tables" home page . These tables show a sharp rise in inequality. However, for reasons explained by a CBO study , these data understate incomes at the top - which is where the biggest action is. The CBO estimates for 1979-1997 can be found here . A more readable summary of the main conclusions of the CBO report is offered by the Center on Budget and Policy Priorities. These data tell us that the gains of the top 1 percent have been much, much bigger than those of the next 4 percent, let alone the top quintile; this suggests that there are even bigger gains as you move to the really rich, the top 0.1 percent or even less. Sure enough, a paper by Piketty and Saez , forthcoming in the Quarterly Journal of Economics, uses income tax data to track the incomes of the very rich since 1913, and finds immense gains at the top. (An amazing observation: the share of percentiles 90-95 has not risen significantly over the last 30 years; all of the gain in the top decile is in the top 5 percent, 80 percent of it in the top 1 percent. So much for 90-10 comparisons as a measure of inequality trends.) This paper is also a convenient source of data on executive compensation. A full set of tables and figures, some of which aren't in the final version, is available in worksheet format .
For part 4, "The price of inequality":A good source for international comparisons of life expectancy, infant mortality, poverty, and other social indicators is the appendix to the UN's Human Development Report . For more focused comparisons of the U.S. with other advanced countries, the work of economists associated with the Luxembourg Income Study is extremely helpful; a nice set of notes by Smeeding provides comparisons of absolute income at the 10th and 90th percentile.
For part 5, "Inequality and politics", I have found the work of McCarty, Poole, and Rosenthal eye-opening. The general source for this material is Poole's home page at Houston. (It's a funny factoid, which does not at all reflect on Poole, that he is the Kenneth L. Lay Professor of Political Science.) To understand how he and his colleagues quantify political positions, and why this is useful, read this methodological note . For an overview of the remarkable polarization of U.S. politics in recent decades, read this set of notes (click on "the Polarization of US Politics").. For an analysis of the relationship between income polarization and political polarization, see this paper .
For the facts about the estate tax, see this report from the Center on Budget and Policy Priorities.
Originally published on the Official Paul Krugman Site, 10.18.02