General Discussion

"I queried a number of Keynesian scholars. Their responses are below, listed alphabetically."

https://stevecotler.com/2009/07/07/keynes-nastiest-wickedest-capitalism/

Thomas Cate, professor of economics, Northern Kentucky University, specializing in the economics of John Maynard Keynes:
“I do not believe that this quote is by Keynes. It appears to be a re-wording of something said by Adam Smith about the business community.“

J. Bradford DeLong, professor of economics, University of California at Berkeley, and former deputy assistant secretary of the U.S. Treasury:
“I’ve never seen it.”

Alexander Kirby, Associate Professor of American History and Government, University of Wisconsin-Stout:
“Beats me, which is why I’d never use it in a scholarly source.”

Michael S. Lawlor, Professor of Economics, Wake Forest University, co-author of New Perspectives on Keynes (1995):
“The quotation you cite is unfamiliar to me.“

N. Gregory Mankiw, Robert M. Beren Professor of Economics, Harvard University, and former chief of the President’s Council of Economic Advisors (he even has a dog named “Keynes”!):
“I don’t know where the quotation comes from.”

Allan Meltzer, University Professor of Political Economy, Carnegie Mellon Tepper School of Business:
“I read most of Keynes’s published papers. I never saw it.”

Donald E. Moggridge, Professor of Economics, University of Toronto:
“The quotation is fabricated.“

James M. Rock, Emeritus Professor of Economics, University of Utah:
“I think it is bogus.”

Robert Skidelsky, Emeritus Professor of Political Economy at the University of Warwick and author of a prize-winning, three-volume biography of Keynes:
“One of the fictions.”

Luigi Zingales, Robert C. McCormack Professor of Entrepreneurship and Finance, University of Chicago Booth School of Business:
“I have never heard of it.”