Monetary valuation of virtual water use in global supply chains

The aim of this thesis has been to develop a new method that can be used to place a monetary figure, reflecting full economic and societal value, on the volumes of fresh water that are consumed and degraded in agri-food product supply chains. Informed by the twin concepts of Total Economic Value and Ecosystem Services, a detailed review of the water valuation literature, which had been conducted within a welfare economic framework, suggested that the current evidence base is limited in terms of the number, type, coverage and robustness of existing estimates. Nonetheless, a method is developed which looks to provide an estimate of the direct use value of water in three agri-food supply chain case studies which are underpinned by raw materials that either significantly impact, or impacted by, global freshwater resources (wheat, tea and potatoes). These case studies are used to illustrate the merit of such an approach in terms of assessing the relative scarcity or impact of water use along globally disparate supply chains, and as a means promoting the trade-offs associated with productive and allocative efficiency gains. Indeed, it is argued that the principal contribution of the thesis is that it highlights the potential for the academic community to enable a more comprehensive approach to the valuation of virtual water flows. Such an approach would supplement the volumetric focus of water footprint assessment, and provide a more useful metric for business users than the current focus on the stress weighted water footprint.