Composite environmental indices-a case of rickety rankings

Shelley M Stevens; Michael K Joy; Wokje Abrahamse; Taciano L Milfont; Lynda M Petherick

doi:10.7717/peerj.16325

Composite environmental indices-a case of rickety rankings

PeerJ. 2023 Dec 11:11:e16325. doi: 10.7717/peerj.16325. eCollection 2023.

Authors

Shelley M Stevens¹, Michael K Joy², Wokje Abrahamse¹, Taciano L Milfont³, Lynda M Petherick¹

Affiliations

¹ School of Geography, Environment and Earth Sciences, Te Herenga Waka Victoria University of Wellington, Wellington, New Zealand.
² School of Government, Te Herenga Waka Victoria University of Wellington, Wellington, New Zealand.
³ School of Psychology, Te Whare Wananga o Waikato University of Waikato, Tauranga, New Zealand.

Abstract

Composite indices have been widely used to rank the environmental performance of nations. Such environmental indices can be useful in communicating complex information as a single value and have the potential to generate political and media awareness of environmental issues. However, poorly constructed, or poorly communicated indices, can hinder efforts to identify environmental failings, and there are considerable differences in rank among existing environmental indices. Here, we provide a review of the conceptual frameworks and methodological choices used for existing environmental indices to enhance our understanding of their accuracy and applicability. In the present study, we review existing global indices according to their conceptual framework (objectives of the index and set of indicators included) and methodological choices made in their construction (e.g., weighting and aggregation). We examine how differences in conceptual frameworks and methodology may yield a more, or less, optimistic view of a country's environment. Our results indicate that (1) multidimensional environmental indices with indicators related to human health and welfare or policy are positively correlated; (2) environment-only indices are positively correlated with one another or are not correlated at all; (3) multidimensional indices and environment-only indices are negatively correlated with each other or are not correlated at all. This indicates that the conceptual frameworks and indicators included may influence a country's rank among different environmental indices. Our results highlight that, when choosing an existing environmental index-or developing a new one-it is important to assess whether the conceptual framework (and associated indicators) and methodological choices are appropriate for the phenomenon being measured and reported on. This is important because the inclusion of confounding indicators in environmental indices may provide a misleading view of the quality of a country's environment.

Keywords: Composite; Environmental; Index; Indices; Ranking.

Grants and funding

This research was supported by a Victoria University of Wellington Doctoral Scholarship (Shelley M. Stevens). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.