The environmental performance index (EPI) is an indicator developed by Yale University and Columbia University (EPI Yale & Columbia) to assess the situation and the implementation of environmental problem-solving in countries worldwide. It has been published every two years since 2006. In each evaluation cycle, components, weighting, and assessment methods are adjusted according to the global environmental context, making it impossible to compare environmental policy progress from year to year. Thailand has therefore developed the Environmental Performance Index in the context of Thailand (EPI Thailand) to allow for evaluation and self-comparison over time. The methods and format are consistent with the evaluation by EPI Yale & Columbia.

EPI Thailand, the Environmental Performance Index in the context of Thailand, is an indicator selected for its calculation method that aligns with the Thai context. It is linked to national policies and plans and is also consistent with the global context. This index can be used as data to more clearly evaluate the status of targets at sub-national plan levels. Therefore, EPI Thailand functions as an assessment tool that precisely identifies environmental issues requiring urgent action under the implementation of the country’s environmental policies.