The Environmental Performance Index (EPI), produced by the Yale Center for Environmental Law and Policy (YCELP), Data-Driven Yale, and the Columbia University Earth Institute Center for International Earth Science Information Network (CEISIN), scores countries from 0 to 100 according to each country's relative performance on a set of environmental indicators. A score of 100 means that the country ranks above a high-quality benchmark for all its indicators. A score of 0 means that the country ranks below some low-quality benchmark for all its indicators. The index is built from 19 national-level indicators relevant to environmental issues, grouped into 9 issues, which are themselves divided into 2 overarching themes: (1) ecosystem vitality and (2) environmental health as it applies to human health. Multiple other data sets were employed to provide context before whittling down to those 19. Each country's score for each indicator is scaled between 0 and 100 to reflect the proximity of its score in that indicator to a high-quality benchmark. The high-quality benchmark can either be a statistical measure—such as the 95th percentile of the distribution of all countries' scores—or a scientifically determined target, such as the World Health Organization's designation of safe and dangerous amounts of particulate matter 2.5 (PM2.5) in the air we breathe. The 19 indicators, each scored been 0 and 100, are then combined with each other to produce the overall EPI score for a country. The indicators are weighted differently depending on the relative reliability of the data that underpin them. A "materiality threshold" is used to determine whether an indicator should count toward a given country's score. Landlocked countries, for example, are not rated according to their marine protected areas or the health of their fisheries. When these indicators are removed, the remaining indicators receive proportionally higher weights in calculating the country total EPI. The EPI uses both primary and secondary data. Primary data come from human-administered surveys or technological monitoring schemes, including data derived from satellites. Secondary data include country-collected statistics, but only when those statistics are submitted to an independent international organization that enforces data reporting and quality requirements. Modeled data are also included. The 2016 global data set is retrieved from the Global Metrics for the Environment—2016 Environmental Performance Index Report. Resource Watch shows only a subset of the data set. For access to the full data set and additional information, see the Learn More link.
Environmental Performance Index
Data are not available for all countries, for all indicators, for all years. The EPI team would like to include several indicators for which data are not available at scale. These include freshwater quality, species loss, indoor air quality of residential and commercial buildings, toxic chemical exposures, municipal solid waste management, nuclear safety, wetlands loss, agricultural soil quality and degradation, recycling rates, and adaptation, vulnerability, and resilience to climate change. The relevance of the EPI to comparing countries depends on the quality of data collected for each indicator. Not all countries collected detailed subnational statistics, such as documenting the water treatment technologies used in rural and remote areas. Before using the EPI and the indicators contained within it for policy purposes, users are encouraged to read the EPI 2016 report to determine the sources and limitations of data underlying each indicator.
Hsu, A., et al. 2016. "2016 Environmental Performance Index." New Haven, CT: Yale University. www.epi.yale.edu. Accessed through Resource Watch, (date). www.resourcewatch.org.