Studies of the undocumented labor force are notoriously difficult to conduct. Standard collection methods, such as questionnaires or employer records, are often inaccurate, inefficient and unavailable. This study gathers primary information about the effect of the raids through personal interviews of employers and employees. The list of companies raided, locations and dates were provided by the INS. Of the eighteen companies studied, data on 10 companies came from phone interviews with the owners, if available, or with managers.