What is Larry Summers' Criticism of the Fed?

The NYT had an article on a conference at the International Monetary Fund with the headline, "Candid Criticism of the Fed That Wasn't On the Agenda." The piece promises blunt criticism of the Fed from former Treasury Secretary and top Obama adviser Larry Summers:

"Now that he is no longer a candidate to head the Federal Reserve, Mr. Summers — who withdrew from consideration this fall in the face of stiff resistance in Congress, with the White House ultimately nominating Janet L. Yellen — was...