The right-leaning Tax Foundation lowered its estimate for the boost to economic growth that it says would result from the House Republican tax bill.

Tax changes under the House legislation would potentially lead to a 3.6 percent higher gross domestic product, rather than 3.9 percent as previously estimated, according to an emailed statement from the Washington policy group Thursday.

The initial error was due to a flaw in the group’s economic model relating to the interaction between federal and state taxes, according to the statement. The Tax Foundation said a “preliminary examination” resulted in the new 3.6 percent figure.

Internal Revenue Code books sit during a House Ways and Means Committee markup hearing in Washington, D.C.
Internal Revenue Code books sit during a House Ways and Means Committee markup hearing in Washington, D.C. Andrew Harrer/Bloomberg

The mistake comes on the heels of a corrected study by another Washington policy group, the Tax Policy Center, last week.

Both corrections came amid an unusual rush by Republicans in the House and Senate to pass complex tax-overhaul legislation in mere weeks. House Republicans plan to vote on tax legislation by Thanksgiving. Senate leaders, who plan to introduce their legislation Thursday, intend to follow with their own full vote within a week of the House.

The bills are expected to differ substantially, and the differences will have to be reconciled.

Bloomberg News