Lakshman Achuthan and Anirvan Banerji are the co-founders of the
Economic Cycle Research Institute (ECRI) with Geoffrey H. Moore,
and the co-authors of Beating the Business Cycle: How to Predict
and Profit from Turning Points in the Economy, published by
Currency Doubleday.    Four of the past six recessions started
during a quarter when GDP was growing, as did 72% of all
recessions in the past 94 years .  How can that be? The answer
is that expansions end -- and recessions begin -- at the peak of
the business cycle, after which the economy begins to contract.
For instance, the initial quarter of the Great Recession of
2007-09 showed 1.7% GDP growth, while the severe 1973-75 and
1981-82 recessions began with 3.9% and 4.9% GDP growth,
respectively.  Revisions are another issue, so GDP could be
contracting and we wouldn't know it for some time. That's why
real-time data often doesn't show GDP turning negative until
about half a year after the recession has actually begun --
that's typically been the case in th