Mark Zandi, the chief economist and co-founder of Moody’s Economy.com was in the midst of a whirlwind day that included two speeches, a panel discussion, a television interview and a visit to the Congressional Budget Office but he still found time for a little extracurricular research. In a taxi on the way to the Park Hyatt hotel in Washington, where he was making a presentation to a bank-industry group, Zandi turned to the driver. “How’s business” he asked.