The Common Sense Initiative (CSI) was launched in 1994 by the U.S. Environmental Protection Agency (EPA) with the broad purpose of seeking cleaner, cheaper, and smarter sector-based approaches to protecting human health and the environment. CSI has been a primary component of EPAs regulatory reinvention efforts aimed at changing the environmental regulatory system to meet current and future challenges. The purpose of this study is to provide an independent review of the four-year Common Sense Initiative effort. It considers both the extent to which CSI succeeded in meeting its goals and what was gained from the sector-based, multi-stakeholder, and consensus aspects of the Initiative. This study also reviews the extent to which EPA took actions in response to recommendations that were made in two major mid-course studies of CSI, and the impact of those actions on the last two years of CSI.