The panel presents four papers that examine the effectiveness of different forms of regulatory instruments in protecting human health and the environment. These papers share a common approach of providing detailed empirical analysis of various public and proprietary databases. The first two papers focus on the effectiveness of policy instruments that address emissions of pollution into various media. The traditional single-media approach of addressing pollution has been criticized as inefficient, and even worse, as having potential to lead to perverse outcomes. For example, regulations that focus on reducing plants’ emissions into the environment may unintentionally lead to increased exposure in the workplace; while regulations that focus on air pollution may lead to increased discharges into water. The first paper by Finger and Gamper examines the effects of the mandatory pollution disclosure program, the Toxic Release Inventory (TRI) program, on worker exposure within the plant using a newly available database on worker exposure. In theory, disclosure of plants’ level of pollution may lead to source reduction, which can contribute to decreasing both emissions and exposure, or alternatively to the shifting of pollutants within the plant. They find that plants have, in fact, reduced worker exposure at a time coinciding with the TRI program implementation. The second paper by Gray and Shadbegian examines EPA’s innovative multimedia regulation of air and water pollution. In 1998 the EPA promulgated the first integrated multi-media regulation – known as the “Cluster Rule” (CR) – to protect human health by decreasing toxic releases by pulp and paper mills into the air and water. By combining air and water regulations, the EPA hoped to diminish the overall regulatory burden on the affected plants. The authors test the impact of the Cluster Rule along multiple dimensions, i.e. on various types of pollutants, on pollution released into various media (air or water), and based on various levels of stringency. They combine data from the Longitudinal Business Database and various pollution and enforcement databases. The next two papers focus on a critical dimension of regulations, i.e. inspections and compliance aspects. They focus on offshore drilling and pipeline safety, which are hotly debated after the Deepwater Horizon Oil Spill, the Exxon Mobil pipeline spill in Montana, and the controversy over Keystone XL pipeline project. Muehlenbachs and Cohen examine group dynamics among inspectors who are in charge of inspecting offshore oil drilling platforms in the Gulf of Mexico. Theories on regulatory capture and social pressure suggest that these group dynamics do matter for the effectiveness of the inspections. They use a unique dataset of inspector’s inspection history for the platforms. Stafford examines the effects of the federal enforcement efforts on the environmental performance of pipeline. She analyzes of all active pipeline operators in the U.S. with more than 100 miles of regulated pipeline, approximately 340 operators. This analysis of inspections, enforcement activities, penalties, and data on operators’ environmental performance provides insight into whether the changes mandated under the Pipeline Safety, Regulatory Certainty, and Job Creation Act are likely to achieve their goal.