It was a call I never expected to receive. I had just returned home from playing indoor tennis on the chilly, windy Sunday afternoon of March 16, 2008. A senior official of the U.S. Federal Reserve Board of Governors was on the phone to discuss the board’s recent invocation, for the first time in decades, of the obscure but explosive Section 13(3) of the Federal Reserve Act. Broadly interpreted, that section empowered the Federal Reserve to lend nearly unlimited cash to virtually anybody: in this case, the Fed planned to loan nearly $29 billion to J.P. Morgan to facilitate the bank’s acquisition of the investment firm Bear Stearns, which was on the edge of bankruptcy, having run through nearly $20 billion of cash in the previous week.
The demise of Bear Stearns was the beginning of a six-month erosion in global financial stability that would culminate with the failure of Lehman Brothers on September 15, 2008, triggering possibly the greatest financial crisis in history. To be sure, the Great Depression of the 1930s involved a far greater collapse in economic activity. But never before had short-term financial markets, the facilitators of everyday commerce, shut down on a global scale. As investors swung from euphoria to fear, deeply liquid markets dried up overnight, leading to a worldwide contraction in economic activity.
The financial crisis that ensued represented an existential crisis for economic forecasting. The conventional method of predicting macroeconomic developments -- econometric modeling, the roots of which lie in the work of John Maynard Keynes -- had failed when it was needed most, much to the chagrin of economists. In the run-up to the crisis, the Federal Reserve Board’s sophisticated forecasting system did not foresee the major risks to the global economy. Nor did the model developed by the International Monetary Fund, which concluded as late as the spring of 2007 that “global economic risks [had] declined” since September 2006 and that “the overall U.S. economy is holding up well . . . [and] the signs elsewhere are