Modelling global water policies

This article develops an analysis of evolving water availability through a novel global Computable General Equilibrium (CGE) model that moves beyond existing approaches by incorporating both precipitation and total water storage (TWS)– a more comprehensive measure of water availability encompassing surface water, groundwater, and soil moisture. To this aim, the article first provides an overview of the problem of economic modelling of water in a general equilibrium context, through a review of CGE models that have attempted to deal with water as a key economic input and its direct and indirect influence on markets and well-being. Secondly, it includes the health effects of inadequate water supply and sanitation (WASH), capturing a key dimension of water availability and its distributional effects. Third, it provides a granular representation of how water enters in the different value chains, providing novel suggestions and a better understanding of how water widespread influence across sectors may contribute to a more significant impact of climate change than estimated by other studies. Simulations are employed to evaluate the costs associated with policy inaction under various water scenarios, including those influenced by climate change, offering crucial guidance for proactive policy interventions.