Friedman, Milton. "The Social Responsibility of Business is to Increase its Profits" New York Times Magazine, September 13, 1970.
LK comment: In 2000 ethicist William Laufer was preparing for a Wharton-sponsored conference on responsible investment and called Dr. Friedman to consult him on the subject. According to the book of the conference:
After a pause, Friedman said: “If people want to invest that way, that’s their business. In
most cases such investing is neither harmful nor helpful.”
See also Markowitz et al (2009).