Macrogeography and income fronts (1965)

Warntz introduced the concept of social mass: 'Whatever is artificially produced or is transported for social purposes is social mass.' Today we talk about 'ecological footprint'.
The USA fall for Piketty's book and that's all right.

But perhaps the Americans should read their own intellectuals more often. For example the writings of late William Warntz on income distribution. Inequality should not be a shock, it was always there.
Here are some of his best works on the subject:

Harvard Papers in Theoretical Geography

GEOGRAPHY OF INCOME SERIES

I. Macroscopic Aspects of Metropolitan Evolution, GH Dutton, 1970

II. Tabulations of Data on Area, Population, Income and Certain Derived Quantities for the 3070
Counties of the 48 Conterminous States of the United States, 1967, GH Dutton, K Kiernan, D Kingsbury, W Warntz, 1971

III. The Geographical Distribution of Income in the Conterminous United States, 1967–68, and the Income Fronts by States, W Warntz, 1971

IV. A Description of the 1967–78 United States Income Potential Surface, D Kingsbury, 1971

V. National and Regional Parameters of Growth and Distribution of Urban Population in the United States, 1790–1970, GH Dutton, 1971

VI. Allometric Growth in Social Systems, MJ Woldenberg, 1971