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. In two other instances, deported workers who had returned to the United States provided information. In one case, a union representative provided information. Requests for anonymity were respected wherever possible. Information for the other 5 companies was estimated by making a comparison with similar companies for which there was information.
Secondary sources for data included newspaper accounts, immigration lawyers and social workers, and the Mexican consulate. A survey of the literature on undocumented labor provides the background against which the study gathered information. The study uses the Regional Economic Modeling Inc. (REMI) computer modeling program which estimates the effect on the regional economy of policy decisions. It uses inputs and outputs of industries affected, consumer spending and investment decisions resulting from the policy decision to estimate the overall effect. The REMI model only looked at the effects of the raids over a 12 month period, making no long-term assumptions.
Although every effort was made to gather accurate information from those interviewed, the study is limited by the accuracy of the information provided by first hand accounts.