By John S. McClenahen Compared with November 2002, mass layoffs and initial claims for unemployment insurance benefits in November 2003 were sharply lower, with the number of initial claims at the lowest level for a November since 1997, the U.S. Labor Department reported Dec. 23. As measured by new filings for unemployment insurance benefits, the number of mass layoffs -- those involving at least 50 people in a single establishment -- was 1,438 in November 2003. Layoffs affected a total of 138,543 workers. In November 2002, there were 2,153 mass layoffs affecting 240,171 workers. Manufacturing accounted for 28% of mass layoffs and 35% of initial jobless claims last month, compared with 33% of the layoffs and 39% of initial claims in November 2002.