Charles F. Roos was a well-known mathematician, economist, and statistician who was a founder and president of the Econometric Society in the 1930s. In 1938, Roos formed the Econometric Institute Inc., which was a research and consulting firm for communities and companies throughout the United States. According to J.W. Nixon's biography for the International Statistical Institute (ISI), of which Roos was an elected member, Roos was the first "to use the concept of disposable personal income in the analysis of consumer demand and size of markets." Nixon goes on to explain that Roos also "originated the concept of corporate purchasing power and used it to help explain the demand for machinery and equipment."
From the guide to the Charles F. Roos Papers, 1935-1965, (David M. Rubenstein Rare Book & Manuscript Library, Duke University)
