Glenn Hubbard, dean of the Columbia Business School, adviser to Bush I and II, and co-author with Tim Kane, of Balance: The Economics of Great Powers from Ancient Rome to Modern America, says economic imbalance led to the downfall of past empires and warns that a similar fate is in store for the U.S. if the political stalemate over budget deficits and entitlements continues.

Listen to the radio interview on WNYC/The Brian Lehrer Show