Survey data from Mexico, 1995, which provides detailed information on environmental performance and determinants, including plant, firm and market characteristics, pollution control costs, relationships with regulators, and measures to improve environmental performance. All plant and respondent identities were kept confidential. The data and survey document are all contained in the zip file. As preparation for their research paper on "What Improves Environmental Performance? Evidence from Mexican Industry," Susmita Dasgupta, Mala Hettige and David Wheeler used survey evidence to analyze the effects of regulation, plant-level management policies, and plant and firm characteristics on environmental performance in Mexican factories. They focused especially on management policies: the degree of effort to improve environmental performance and the type of management strategy adopted. The survey, conducted in the fall of 1995, focused on the food, chemicals, non-metallic minerals and metals sectors, which account for 75 percent to 95 percent of Mexico’s total industrial pollution. 236 facilities in the survey were chosen as representative of Mexican factories as defined by sector, size and location. The survey was designed by a World Bank team, conducted by the Monterrey Institute of Technology, and supported by the Mexico National Environment Ministry (SEMARNAP) and the Mexican National Association of Industries. The survey provides detailed information on performance and determinants, including plant, firm and market characteristics, pollution control costs, relationships with regulators, and measures to improve environmental performance. All plant and respondent identities were kept confidential. It is important to note the information derived from the survey was self-reported. No independently audited data on pollution and regulatory compliance was associated with the survey. Finally, with confidentiality assured, 49 percent of survey respondents admitted non-compliance with regulations. With no benchmarks, only educated guesses can be made about the degree of upward bias. Evidence from Indonesia, a country with similar regulations but weaker monitoring and enforcement, revealed a non-compliance rate of 64 percent. This suggests that the degree of upward bias in the Mexican self-assessment may be small. In any case, our analysis for this research focuses on relative, not absolute, performance.