My colleagues and I recently released the 2012 Environmental Performance Index (EPI) at the annual World Economic Forum meeting in Davos, Switzerland. Countries that ranked high rejoiced; those low on the list sought explanation.

Nobody wants to look bad.

The EPI is a biennial report produced jointly by Yale and Columbia Universities that ranks countries on their environmental performance across a variety of measures, from pesticide regulation and forest loss to child mortality. There were 22 measures this year, each categorized under one of two overarching categories: environmental health or ecosystem vitality. After long hours of number crunching, the EPI produces a single number that ranks countries against each other. (You can find your country's rank here.) MORE