Paul Krugman is a respected trade theorist. But he does not speak authoritatively on subjects on which he has no expertise. Monetary economics is not his field of expertise. Krugman’s research background does not qualify him as an authority on Milton Friedman’s work.
Krugman’s scholarly publications rarely mentioned Friedman and,when they did,they acknowledged the contributions of Friedman and monetarism in a way that contradicts his (2007a) essay on Friedman. Friedman’s reputation is intact despite Krugman’s deplorable efforts to denigrate him and his contributions.
Damn, here's more from Anna Schwartz, a long time friend and co-author of Milton Friedman.
Here is the target of Anna Schwatz's attack, Paul Krugman's "Who was Milton Friedman?"