The Relation of the Movements of Bond Yields to the Grades of the Bonds -- Economic 'Drift'

Frederick R. Macaulay, Some Theoretical Problems Suggested by the Movements of Interest Rates, Bond Yields and Stock Prices in the United States since 1856 (NBER, 1938), chap. 4, https://www.nber.org/books-and-chapters/some-theoretical-problems-suggested-movements-interest-rates-bond-yields-and-stock-prices-united/relation-movements-bond-yields-grades-bonds-economic-drift.