Milton Friedman, the Nobel Prize-winning economist who advocated an unfettered free market and had the ear of Presidents Richard Nixon, Gerald Ford and Ronald Reagan, died Thursday. He was 94. Friedman died in San Francisco, said Robert Fanger, a spokesman for the Milton and Rose D. Friedman Foundation in Indianapolis. He did not know the cause of death. "Milton's passion for freedom and liberty has influenced more lives than he ever could possibly know," Gordon St. Angelo, the foundation's president and CEO, said in a statement. "His writings and ideas have transformed the minds of US presidents, world leaders, entrepreneurs and freshmen economic majors alike."