Read Paul Krugman, Scott Sumner, Ezra Klein, and others on this. My thinking is simple. Public choice considerations constrain a looser monetary policy with either candidate. Otherwise, it is easier for me to imagine Summers having credibility with a Republican administration, and having a real voice, relative to Yellen. He simply has more right-wing street cred, keeping in mind that Yellen is a former Professor from Berkeley who has never really taken heat from the left, unlike Summers. I think that overall the voice of the Fed within government is a clear positive. The chance of a Republican administration, come the next election, is probably at least forty percent. Thus I would prefer Summers.