This guy rocked (the world of economics).
If it hadn't been for guys like Milt, would the current day USA economically look much more like current day Germany, France, Sweden or Italy (that is, stagnating and decaying)? That's certainly where the leftists antagonists of Harvard, MIT and the other "salt-water" institutions wanted to take our country back in the '70s. And for a while they did just that ("We are all Keynesians now...")
Note that Milt wasn't totally libertarian or anarcho-capitalist; he still advocated a central bank governmental manipulation of the money supply. Still, that's a LOT less of an intrusion into the economy than social(ist) programs, or wage and price manipulations.