The Yale Center for Environmental Law and Policy (YCELP) has been developing indicators and indices of environmental sustainability and performance since 1998. This work arose from the Millennium Development Goals (MDGs), in particular Goal 7, which charged nations to “ensure sustainability” but lacked any clear metrics to define what was meant. YCELP, in collaboration with Columbia University and the World Economic Forum, has since responded to the need for environmental performance metrics with four iterations each of the Environmental Sustainability Index (ESI) and the Environmental Performance Index (EPI), of which the latest launched in January 2014. This presentation will distill 15 years of experience in researching and constructing performance indicators and composite indices for the purposes of informing decision-makers, governments, and the public on how policies to protect environment health and ecosystems are performing, relative to the global context and to peers. It will also provide an overview of the challenges in bridging scientific data to policy, both from a methodological and a practical perspective.


Angel Hsu, PhD, is joint faculty at the Yale School of Forestry and Environmental Studies in New Haven, Connecticut, and Yale-NUS College in Singapore. She is also Director of the Environmental Performance Measurement Program at the Yale Center for Environmental Law and Policy, where she is Principal Investigator and Lead Author of the Environmental Performance Index. Her research seeks to advance data-driven approaches to environmental decision-making and policy. Prior to Yale, Angel was at the World Resources Institute, where she developed corporate greenhouse gas accounting and reporting initiatives in Mexico, Brazil, India, the Philippines, and China, where she managed and led WRI’s efforts. She has written in and been cited by major media outlets, including The Economist and The New York Times, and has provided expert testimony for the US-China Economic and Security Review Commission. In 2010–2011, she was a Fulbright Scholar to China. She holds a PhD in Forestry and Environmental Studies from Yale University, an MPhil in Environmental Policy from the University of Cambridge, and a BS in Biology and BA in Political Science from Wake Forest University in Winston-Salem, North Carolina.