News Summary: US consumer prices flat last month Associated Press Copyright 2013 Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed. Updated 1:32 pm, Wednesday, January 16, 2013 A measure of U.S. consumer prices was unchanged in December, the Labor Department said. The producer price index, which measures price changes before they reach the consumer, fell for the third straight month in December.