Description
The 2018 Environmental Performance Index (EPI) ranks 180 countries on 24 performance indicators across ten issue categories covering environmental health and ecosystem vitality. The index is issued by Yale University, Colombia University , World Economic Forum every 2 years.

Index Calculation Mechanism
The index construct scores for each of the 24 indicators, placing them onto a common scale where 0 indicates worst performance and 100 indicates best performance. The indicator scores are then multiplied by weights, and added together to produce scores at the levels of the issue categories, policy objectives, and the final EPI.