There is significant variation in the extent governments are involved in establishing and administering private regulatory schemes (Abbott & Snidal, 2009; J. Green, 2014). Some are undertaken seemingly without any government involvement, while others are initiated as partnerships with firms and governments sharing administrative tasks such as setting standards and monitoring compliance. In this study I will examine Environmental Management System standards – rules, procedures and processes firms adopt to measure, protect and improve their environmental performance. To determine whether government involvement improves outcomes, I will compare the performance of firms (within industries) that have adopted the Eco-Management and Audit Scheme (EMAS), a transnational private standard with shared public-private governance, with those that have adopted ISO 14001, a standard predominantly administered by firms (Clapp, 2001).