Greenspan Calls for Better Economic Data; Treasury Official Talks Taxes.

Byline: Avrum D. Lank

Mar. 28--WASHINGTON--Government statistical data understates both productivity and growth, Federal Reserve Board Chairman Alan Greenspan told a group of economists here Tuesday, while Treasury Secretary Paul O'Neill said that just sending a tax rebate to Americans will not do enough to ensure future prosperity.

Instead, O'Neill said, any rebate must be part of a larger package that includes a reduction in marginal tax rates.

While O'Neill's comments were straightforward, Greenspan's remarks contained a more important message for investors in the long run, many of those in attendance said. Both spoke to the annual spring conference of the National Association for Business Economics.

Much of Greenspan's …