Why Janet Yellen and Why Not Larry Summers

Dr.Yellen has a perfectly solid relationship with Bernanke, as best as I can tell, but she’s more of her own thinker within the institution. She has spent her time as vice chairwoman urging Bernanke and her other fellow policymakers to shift policy to try to do more to combat unemployment, and thinking through ways to do just that.WP

On the other hand Geithner, Summers, Gene Sperling are leftovers from the Clinton past and see as key influential voices advising the president.
And they are Wall Street men.