The Labor Force and Earnings or Income in Different Cities, States, Nations, and Income Groups at a Given Time

Clarence D. Long, The Labor Force under Changing Income and Employment (Princeton University Press, 1958), chap. 4, https://www.nber.org/books-and-chapters/labor-force-under-changing-income-and-employment/labor-force-and-earnings-or-income-different-cities-states-nations-and-income-groups-given-time.