Paul Krugman says that they are not his children, but his great-grandchildren:
Roots of Macroeconomic Ignorance - NYTimes.com: have some quibbles: Brad, I think, telescopes the process. Today’s freshwater economists don’t believe in Friedman-type monetarism; they’re two intellectual generations of intellectual retrogression beyond that...
Nick Rowe says that they are nothing like his children--that they are Friedman's opposites:
Worthwhile Canadian Initiative: Do Keynesians understand their own models?: If we lived in a world of barter exchange, or in a world where people could use barter exchange at minimal cost, Keynesian macroeconomics would make no sense whatsoever.... [D]o Keynesians understand this? Milton Friedman understood this. Monetarism, rather obviously, would make no sense whatsoever in a non-monetary economy. As Milton Friedman (almost) said, recessions are always and everywhere a monetary phenomenon. He (and Anna Schwartz) wrote a very large book arguing that the Depression was a monetary phenomenon.
If you drew a line, and put Real Business Cycle theory at one end of the spectrum, who would be a natural candidate to put at the other end of the spectrum? I can't think of a better candidate than Milton Friedman. At one end of the line you have people who say that money plays no role in the business cycle. And at the other end you have Milton Friedman. Keynesians are somewhere in between.
So it seems counter-intuitive for Brad DeLong to blame Milton Friedman for the rise of Real Business Cycle theory. The two are polar opposites.
You could argue that the research program called RBC theory, or Classical Macroeconomics (a strange name for something that only started in the 1980's), is an example of the Ricardian Vice. RBC theory is what happens when you insist on modelling everything formally. But who should we blame for the Ricardian Vice? Ricardo, obviously. But if we are looking for more recent culprits, you could argue that, say, James Tobin, an excellent Keynesian economist, is at least as guilty as Milton Friedman.... It makes about as much sense to blame Friedman for the consequences of the Ricardian Vice as it does to blame Keynes. Both gave the model-builders something to model, but they themselves were more talkers. Personally, I blame Tobin for Lucas, and everything that followed. Well, maybe that's a bit unfair...
I think that you can blame Friedman for the current crop of ignorance much more sensibly that you can blame Tobin.
In the 1950s and 1960s and 1970s Milton Friedman faced a rhetorical problem. He was a laissez-faire libertarian. But he also believed that macroeconomic stabilization required that the central bank be always in the market, buying and selling government bonds in order to match the supply of liquid cash money to the demand, and so make Say's Law true in practice even though it was false in theory.
Such a policy of constant government intervention to continually rebalance aggregate demand is hardly a laissez-faire hands-off libertarian policy, is it?
Friedman, however, set about trying to maximize the rhetorical distance between his position--which was merely the "neutral," passive policy of maintaining the money stock growth rate at a constant--and the position of other macroeconomists, which was an "activist," interventionist policy of having the government disturb the natural workings of the free market. Something went wrong, Friedman claimed, only when a government stepped away from the "neutral" monetary policy of the constant growth rate rule and did something else.
It was, I think, that description of optimal monetary policy--not "the central bank has to be constantly intervening in order to offset shocks to cash demand by households and businesses, shocks to desired reserves on the part of banks, and shocks to the financial depth of the banking system" but "the central bank needs to keep its nose out of the economy, sit on its hands, and do nothing but maintain a constant growth rate for the money stock"--that set the stage for what was to follow in Chicago.
First, Friedman's rhetorical doctrine eliminated the cognitive dissonance between normal laissez-faire policies and optimal macro policy: both were "neutral" in the sense of the government "not interfering" with the natural equilibrium of the market. Second, Friedman's rhetorical doctrine eliminated all interesting macroeconomic questions: if the government followed the proper "neutral" policy, then there could be no macroeconomic problems. Third, generations of Chicago that had been weaned on this diet turned out to know nothing about macro and monetary issues when they became important again.
It is in this sense, I think, that I blame Milton Friedman: he sold the Chicago School an interventionist, technocratic, managerial optimal monetary policy under the pretense that it was something--laissez-faire--that it was not.