This paper investigates the nature and the presence of bubbles in financial markets. Are bubbles consistent with rationality? If they are, do they, like Ponzi games, require the presence of new players forever? Do they imply impossible events in finite time, such as negative prices? Do they need...

The U.S. economy has grown faster--and scored higher on many other macroeconomic metrics--when the President of the United States is a Democrat rather than a Republican. For many measures, including real GDP growth (on which we concentrate), the performance gap is both large and statistically...

This paper examines the macroeconomic dynamics of the 2007-09 recession in the United States and the subsequent slow recovery. Using a dynamic factor model with 200 variables, we reach three main conclusions. First, although many of the events of the 2007-2009 collapse were unprecedented, their...