The overall EPI results offer a useful snapshot of environmental performance. But breaking down the results into peer groups offers an even more valuable perspective because it allows for comparisons between countries. The peer group analysis gives policymakers a way to understand the context of their policy choices and guidance on what is possible in the way of policy results given their circumstances. The policies and programs of the peer group leaders present an important guide to best practices and the most efficient approaches to improving environmental health and ecosystem vitality with similar challenges and opportunities.
OECD countries occupy four of the top five ranks in the 2008 EPI. Most of the OECD countries are in the top quarter of the Index, and all are in the top half. These relatively wealthy countries all have quite good Environmental Health results. But their scores on the various metrics of Ecosystem Vitality vary widely. Some of these nations, notably the Scandinavians, have distinct geographic advantages, including large land areas and low population densities. But their success is also a function of concerted policy effort and deep commitment to environmental values across their public and business communities.
None of the Least Developed Countries (LDC) were in the top half of the EPI, and the bottom 14 countries in the EPI are found in this group. With little access to financial resources for immediate needs like nutrition and disease, many of these countries are struggling to make even baseline efforts on environmental health. Their lack of development translates into limited pollution stress and thus contributes to relatively strong scores on air emissions, climate change, and biodiversity.
High population density countries are spread throughout the EPI. Germany, for example, sits in the 13th position while Burundi ranks 132nd. High populations density generates special challenges, but the high-ranked performers in this category demonstrate that population density is not an insurmountable barrier to good environmental quality. Many of the lower ranked countries in this grouping face challenges, but can look to their higher ranking peers for guidance on how to develop in an environmentally sustainable manner.
Other peer groups, like the African Union, the Alliance of Small Island States, the Desert Countries, and the Newly Independent States contain are spread across the EPI. Each of these peer groups is largely populated by developing countries that struggle with a wide variety of challenges, including a lack of natural resources like water and arable land, as well as the burden of poverty. Overall, these peer groups show much more diversity than do groupings like the OECD and the LDCs. This results implies that countries in the midst of economic transitions vary widely in how well they fold environmental protection into their development strategies.