William Stanley Jevons was an English economist and logician.
William Stanley Jevons
Portrait of W. Stanley Jevons at 42, by G. F. Stodart
Portrait of Jevons published in the Popular Science Monthly in 1877
Jevons' Logic Piano in the Sydney Powerhouse Museum in 2006
Irving Fisher was an American economist, statistician, inventor, eugenicist and progressive social campaigner. He was one of the earliest American neoclassical economists, though his later work on debt deflation has been embraced by the post-Keynesian school. Joseph Schumpeter described him as "the greatest economist the United States has ever produced", an assessment later repeated by James Tobin and Milton Friedman.
Fisher photographed by George Grantham Bain in 1927
Theory of interest as determined by impatience to spend income and opportunity to invest it, 1930