___One issue not on the agenda but a hot topic at the edges of the conference: The campaigns waged by supporters of Yellen and Summers to secure the nomination of their candidate. From the use of Twitter and opinion columns to behind-the-scenes lobbying and letters signed by Senate Democrats, the battle to influence the president's mind has been raging. Fed officials here have been careful not to take sides in the contest, at least not publicly. They do agree on this: They've not seen anything quite like this summer's public jousting. Dennis Lockhart, head of the Atlanta regional Fed bank, called it unprecedented. But he said the jockeying over the chairman's job is having no effect on the Fed's policymaking. "The chairman's leadership is as strong as it has ever been," Lockhart said in an interview on CNBC. He was addressing concerns that the prolonged contest to succeed Bernanke might weaken his influence as chairman by solidifying the perception that he's a lame duck. James Bullard, head of the St. Louis Federal Reserve Bank, noted that a change in the Fed chairmanship has been fairly unusual since World War II. Bernanke has served for nearly eight years. Two of his predecessors â¿¿ William McChesney Martin (1951-1970) and Alan Greenspan (1987-2006) â¿¿ served for a combined nearly four decades. As for whom he would prefer as chairman, Yellen or Summers, Bullard, also interviewed on CNBC, struck a diplomatic note. They're both "great economists," he said. ___ Yellen did have a modest role to play at this year's conference, serving as the moderator for Saturday's session. It was a job she performed with fair minded diligence. "My job today is to be a ruthless time keeper," she told the crowd in her opening comments. And she kept to her word, turning over numbered cards signaling to the presenters how much time they had left to present papers on such esoteric topics as global liquidity and cross-border capital flows.