Milton Friedman, one of the most influential economists of the past century and winner of a 1976 Nobel Prize, died on Thursday morning of heart failure at a San Francisco area hospital, a spokeswoman for his family said. He was 94.

A free-market economist, Friedman preached free enterprise in the face of government regulation and advocated a monetary policy that called for steady growth in money supplies.

His ideas played a pivotal role in informing the governing philosophies of world leaders like former British Prime Minister Margaret Thatcher and former U.S. President Ronald Reagan.

Friedman believed that economic stabilization policy did not operate like a thermostat, because of the 'long and variable lag' between policy actions and their ultimate effects.