The Ins and Outs of Water Use – A Review of Multi-Region Input–output Analysis and Water Footprints for Regional Sustainability Analysis and Policy

This paper reviews current knowledge about water footprints (WFs) and the role of input-output techniques. We first provide an overview of the prevailing 'bottom-up', process-based methods and their strengths and limitations. This overview leads to discussion of the benefits of combining process-based water footprints with information from input-output techniques. The central theme and proposition is that environmental multi-region input-output analysis (E-MRIO) has a powerful capacity to establish the geography of embodied water, and to complement process-based approaches to WF by expanding their supply-chain coverage. Combining process and input-output information provides valuable information for a diverse set of water planning and water policy objectives. A comprehensive and systematic outline of potential policy applications of E-MRIO (and process analysis methods) is presented.