Chance of a Depression in America is one in five

A Harvard economist has determined that the U.S. economy has a one in five chance of slipping into a Depression.

His research is painstakingly thorough. And it tries to match up a potential crash in the stock market with the current economic woes.

A Depression is not the end of the world. Our parents and their parents survived it. We can, too. But it is important now to prepare in your spending and saving.

Professor Robert J. Barro's research is worthy to read as a matter of education as to the times we face now, and potentially worse to come.

Here is an excerpt:

The U.S. macroeconomy has been so tame for so long that it's impossible to get an accurate reading about depression odds just from the U.S. data. My approach uses long-term data for many countries and takes into account the historical linkages between depressions and stock-market crashes.

(The research is described in "Stock-Market Crashes and Depressions," a working paper Jose Ursua and I wrote for the National Bureau of Economic Research last month.)

The bottom line is that there is ample reason to worry about slipping into a depression. There is a roughly one-in-five chance that U.S. GDP and consumption will fall by 10% or more, something not seen since the early 1930s.

Our research classifies just two such U.S. events since 1870: the Great Depression from 1929 to 1933, with a macroeconomic decline by 25%, and the post-World War I years from 1917 to 1921, with a fall by 16%.

We also assembled long-term data on GDP, consumption and stock-market returns for 33 other countries, sometimes going back as far as 1870. Our conjecture was that depressions would be closely connected to stock-market crashes (at least in the sense that a crash would signal a substantially increased chance of a depression).

This idea seems to conflict with the oft-repeated 1966 quip from Paul Samuelson that "The stock market has predicted nine of the last five recessions." The line is clever, but it unfairly denigrates the predictive power of stock markets.

In fact, knowing that a stock-market crash has occurred sharply raises the odds of depression. And, in reverse, knowing that there is no stock-market crash makes a depression less likely.

Our data reveal 251 stock-market crashes (defined as cumulative real returns of -25% or less) and 97 depressions. In 71 cases, the timing of a market crash matched up to a depression. For example, the U.S. had a stock-market crash of 55% between 1929-31 and a macroeconomic decline of 25% for 1929-33.

Likewise, Finland had a stock-market crash of 47% for 1989-91 and a macroeconomic fall of 13% for 1989-93.

In this relatively favorable scenario, we may follow the path recently sketched by Federal Reserve Chairman Ben Bernanke, with the economy recovering by 2010. On the other hand, the 59 nonwar depressions in our sample have an average duration of nearly four years, which, if we have one here, means that it is likely recovery would not be substantial until 2012.

Given our situation, it is right that radical government policies should be considered if they promise to lower the probability and likely size of a depression. However, many governmental actions -- including several pursued by Franklin Roosevelt during the Great Depression -- can make things worse.

I wish I could be confident that the array of U.S. policies already in place and those likely forthcoming will be helpful. But I think it more likely that the economy will eventually recover despite these policies, rather than because of them.