Mostly, that since he died on November 16, 2006, the American economy has become a very “dry dessert”.
And why´s that?
Most likely because Ben Bernanke broke the promise he made to Friedman in 2002:
Let me end my talk by abusing slightly my status as an official representative of the Federal Reserve. I would like to say to Milton and Anna: Regarding the Great Depression. You’re right, we did it. We’re very sorry. But thanks to you, we won’t do it again.
PS. The oil shocks in 2004-08 were significant, so there were some “spillovers” to the core measure.