How do you change regimes when the head of the old one isn't leaving? That will be the question facing Federal Reserve chair nominee Kevin Warsh next month once confirmed by the Senate , now that outgoing Chair Jerome Powell has confirmed he will stick around indefinitely as a voting member of the Fed's Board of Governors. Powell's decision to stay has little precedent in Fed history, but it may be less disruptive to Warsh's plans than it might otherwise seem. Powell said at a Wednesday press