The Ministry of Economy, Trade and Industry said Thursday that a data error has forced it to revise downward its production data on personal computers for the past 12 years.
The correction includes a 21 percent cut for 2001.
A METI official attributed the error to the duplication of output data from a major PC maker and several of its affiliated makers that it had outsourced production to.
The 2001 output was corrected from 14.36 million units to 11.34 million. METI also revised all monthly data dating back to October 1990, when it began taking into account the production figures of the affiliated makers.
As a component of monthly industrial production data, a key economic indicator measuring output at mines and factories, the revision is expected to affect monthly moves of the index by a margin of 0.2 percentage point, but not its trend, the official said.
The weight of PCs in the overall output, which is fixed on the basis of data for 1995, will also be revised down from 0.624 percent to 0.596 percent, he said.
The ministry plans to finalize revisions by the time it announces annual adjustments in mid-April, and has started examining the accuracy of other components, the official said.