That view is shared by private economists like Stephen S. Roach of Morgan Stanley and Bruce Steinberg of Merrill Lynch. The goal is to halt a systematic overstatement of G.D.P. caused primarily by the sharp drop in computer prices since 1987, the base year. In fact, it is many times cheaper. The distortion becomes greater over time. While only the method of measurement has changed, that may well have a negative effect on the way many people view the economy.
Many specialists insist the changes only scratch the surface.
And since the components no longer add up, economists say it will be even harder to construct meaningful forecasts and provide readily understandable data for policy makers. Indeed, some critics say it is time to start over with entirely different measures. Richard M. Salsman, an economist at H. C. Wainwright Economics in Boston, disparages the G.D.P. accounts as based on an era when most economists believed that consumption was the driving force of the economy. He argues that the statistic undervalues business investment, does not capture the dynamism of new inventions and fails to account correctly for transactions that take place among companies. It excludes the bulk of activity that goes on.