Rethinking the Foundations of Sustainability Measurement: The Limitations of the Environmental Sustainability Index (ESI)

The objective of sustainability measurement is to move environmental decision making toward more rigorous, quantitative and empirical foundations. One of the most comprehensive attempts to lay out the foundations for sustainability measurement has been offered by the Environmental Sustainability Index (ESI). This paper aims to advance the science of sustainability measurement by assessing the validity and reliability of this composite index in order to provide new insights for future indicator development. The architecture of the ESI is validated against the Pressure-State-Response (PSR) model, after which an exploratory factor analysis is conducted to reveal the latent structure of the index. Further, the performance of the ESI is tested in cross-national regression models. The results indicate a lack of consistency with the well established PSR model and a potential bias towards economically developed countries grounded in the architecture and weighting mechanism of the index. A re-weighted index (Equivalised ESI) is constructed, resulting in a new ranking of countries’ sustainability. The Equivalised ESI improves the measurement qualities of the index, and in so doing actually reinforces the rich-country bias of the ESI. Put differently, the Equivalised ESI brings the deficiencies of the original ESI to the fore. This paper illustrates that there are serious conceptual problems and validity concerns with defining the ESI as a sustainability measure. Taken together, the findings reinforce the need to reconsider future foundations of sustainability measurement in order to ensure that it is clear both what is being measured and how well.