The authors indicate how science and social science can be combined to assess the range and effectiveness of policy alternatives available to environmental decision‐makers. They focus on cost‐effective regulatory alternatives to the Los Angeles particulate sulfate problem. Both sciences are applied to the relationship of emissions to pollution levels and environmental quality. They reject the notion that a simple reduction in emissions leads to a commensurate reduction in pollution levels. The problem of applying licenses and emissions fees are reviewed, as are the difficulties of political feasibil