The US Bureau of Labor Statistics (BLS) maintains and analyzes data on "virtually all agreements in both private industry and state and local government covering 1,000 workers or more" at the Collective Bargaining Agreements homepage. The site provides statistics on major work stoppages (1947-1998) in addition to the quarterly BLS publication Compensation and Working Conditions. Also available is the Collective Bargaining Agreements File with a detailed list of agreements available to researchers for a fee by mail.