The Architecture and Measurement of an Ecosystem Services Index

This paper describes the construction of an ecological services index (ESI). An ESI is meant to summarize and track over time the magnitude of beneficial services arising from the natural environment. A central task of this paper is to define rigorously ecosystem services so that services can be counted in an economically and ecologically defensible manner—a requirement if ecological contributions to welfare are to be incorporated into the national accounts. This paper advocates a particular economic structure and relates it to index theory and makes concrete recommendations for the measurement of such an index.