[Excerpt] The U.S. Bureau of Labor Statistics (BLS) conducts the Mass Layoff Statistics (MLS) program to provide information on large-scale layoff events and the characteristics of the dislocated workers. This report summarizes data on extended mass layoffs for 2010. The MLS program defines extended mass layoff events as the filing of 50 or more initial claims for unemployment insurance benefits against an employer during a 5-week period, with at least 50 workers separated for more than 30 days. Since 2004, the scope of the layoff data series was redefined to include only the private nonfarm economy. (See the technical note of this report for additional information on the concepts and definitions used.)