Martina Sartori

Water Scarcity and Virtual Water Trade in the Mediterranean

Virtual water trade refers to the implicit content of water in the production of goods and services. When trade is undertaken, there is an implicit exchange of water. Furthermore, when water gets scarce, water intensive goods become more expensive to produce and the economy compensates through higher water imports.This paper is about applying the concept of virtual water to the problem of future water scarcity in the Mediterranean area, also induced by the climate change. The aim is assessing to what extent water trade is a viable adaptation option to the problem of water scarcity. To this end, a computable general equilibrium model is extended with satellite data on sectoral water consumption, and used to assess future scenarios of water availability.It is found that virtual trade may curb the negative effect of water scarcity, yet the consequences in terms of income and welfare remain quite significant, especially for some regions.

A Decomposition and Comparison Analysis of International Water Footprint Time Series

This paper deals with the construction, decomposition and comparison of water footprint time series in 40 countries and one aggregate macro-region, in the period 1995–2009. The analysis of the different “footpaths” allows us to investigate the possible causes behind the time evolution of water footprints in the various countries. We notice that the physical and economic impact of economic growth on water resources has been significantly lower than what it could have been, for several reasons. First, both production and consumption patterns are shifting away from water-intensive goods. Second, a large part of consumed water is actually not blue water, susceptible to alternative uses. Finally, we do not find strong evidence of gains in the economic productivity of water (dollars per water unit) in many countries, but we do find evidence of indirect efficiency gains, related to a composition of factors in the production processes.

Climate Change, Tourism and Water Resources in the Mediterranean:a General Equilibrium Analysis

This paper presents and discusses some quantitative results obtained in assessing the economic impact of variations in tourism flows, induced by climate change, for some Mediterranean countries. Estimates by a regional climate model are used to build a Tourism Climate Index, which indicates the suitability of climate, in certain locations, for general outdoor activities. As climate change is expected to affect a number of variables like temperature, wind and precipitations, it will have consequences on the degree of attractiveness of touristic destinations. We estimate the macroeconomic consequences of changing tourism flows by means of a computable general equilibrium model. We found that more incoming tourists will increase income and welfare, but this phenomenon will also induce a change in the productive structure, with a decline in agriculture and manufacturing, partially compensated by an expansion of service industries. We found that, in most countries, the decline in agriculture entails a lower demand for water, counteracting the additional demand for water coming from tourists and bringing about a lower water consumption overall.

Unfolding the Potential of the Virtual Water Concept. What is Still Under Debate

The concept of virtual water refers to the volume of water used in the production of a commodity or a service. The concept was identified by the geographer Tony Allan in the early 1990s, to draw attention on the global economic processes that ameliorate local water deficits in the MENA region and elsewhere. Since its inception, the virtual water concept has inspired a flourishing literature on how to address global water resource scarcity vis-a-vis commodity production and consumption in a variety of disciplines, but also has been the object of a number of critiques. Against this backdrop, the aim of the study is, first, to conduct a thorough review of the conceptual definition of the concept, its critics and applications. Secondly, to analyse its theoretical underpinnings and, in particular, its relationship with economic theory. The study argues that, despite not being a policy tool itself, the virtual water concept can reveal aspects related to production, consumption and trade in goods which monetary indicators do not capture. Its potential as an indicator for informing decision-making in water management and policy, as well as commodity trade policy, still has to be fully unfolded.

Climate change, tourism and water resources in the Mediterranean

This paper presents and discusses some quantitative results obtained in assessing the economic impact of variations in tourism flows, induced by climate change, for some Mediterranean countries. Estimates by a regional climate model are used to build a Tourism Climate Index, which indicates the suitability of climate, in certain locations, for general outdoor activities. As climate change is expected to affect a number of variables like temperature, wind and precipitations, it will have consequences on the degree of attractiveness of touristic destinations. We estimate the macroeconomic consequences of changing tourism flows by means of a computable general equilibrium model. We found that more incoming tourists will increase income and welfare, but this phenomenon will also induce a change in the productive structure, with a decline in agriculture and manufacturing, partially compensated by an expansion of service industries. We found that, in most countries, the decline in agriculture entails a lower demand for water, counteracting the additional demand for water coming from tourists and bringing about a lower water consumption overall.

Trade-Offs in Water Policy: System-Wide Implications of Changing Water Availability and Agricultural Productivity in the Mediterranean Economies by 2050

We evaluate the structural consequences of water availability scenarios in the Mediterranean, following a multidisciplinary approach and a sequential modelling methodology. This includes an assessment of future water availability and a general equilibrium macroeconomic analysis of changes in agricultural productivity. Lower productivity in agriculture, induced by reduced water availability, generates negative consequences in terms of real income and welfare. The magnitude of the loss depends on the amount of the productivity shock, but also on the share of agricultural activities in the economy and on the stringency of the environmental regulation. We find evidence of a dramatic cut in the supply of water for agriculture in the Middle East. We consider alternative scenarios, differing in terms of stringency of environmental regulation and assumptions about water efficiency. The largest welfare losses turn out to be in Morocco and Tunisia, in the �worst� scenario NM. Other very relevant impacts can be observed in Turkey, Italy and Rest of Middle East and North Africa (XMENA). There are also clear differences among the scenarios. First, applying a constraint on access to environmental water reserves only for Europe does make a big difference for non-European countries (Morocco, Tunisia and XMENA), implying that governments in the Middle-East could respond to increasing water scarcity by accepting, to some extent, lower environmental quality (deterioration of aquatic environments). Second, improvements in water efficiency, as envisaged in the simulation exercise, appear to curb the economic impact of water scarcity quite significantly. This is especially true for countries in the North, whereas efficiency does not compensate for a strict environmental policy in the South.

To what extent will climate and land-use change affect EU-28 agriculture? A computable general equilibrium analysis

This paper assesses the structural, joint implications of climate and land-use change on agriculture in the European Union, by means of a computable general equilibrium model of the world economy. The counterfactual simulations are conducted at the year 2050 under the second Shared Socioeconomic Pathway. We find that climate and land-use change are likely to affect agricultural systems very differently across Europe. Northern countries are expected to benefit from climate change impacts, whereas other areas in Europe will suffer negative consequences in terms of reduced agricultural output, real income and welfare. The most vulnerable region is not made of Mediterranean countries, but rather Central Europe. Our results suggest that climate and land-use changes may exacerbate existing disparities within the EU. Therefore, appropriate adaptation strategies and a more flexible land-use are required to limit these negative consequences and possibly exploit the beneficial effects of climate change in some countries.

Why Can Sectoral Shocks Lead to Sizable Macroeconomic Fluctuations? Assessing Alternative Theories by Means of Stochastic Simulation with a General Equilibrium Model

Relatively small sectoral productivity shocks could lead to sizable macroeconomic variability. Whereas most contributions in the literature analyze the issue of aggregate sensitivity using simple general equilibrium models, a novel approach is proposed in this paper, based on stochastic simulations with a global CGE model. We estimate the statistical distribution of the real GDP in 109 countries, assuming that the productivities of the industrial value added composites are identically and independently distributed random variables. We subsequently undertake a series of regressions in which the standard error of the GDP is expressed as a function of variables measuring the �granularity� of the economy, the distribution of input-output trade flows, and the degree of foreign trade openness. We find that the variability of the GDP, induced by sectoral shocks, is basically determined by the degree of industrial concentration as counted by the Herfindhal index of industrial value added. The degree of centrality in inter-industrial connectivity, measured by the standard deviation of second order degrees, is mildly significant, but it is also correlated with the industrial concentration index. After controlling for the correlation effect, we find that connectivity turns out to be statistically significant, although less so than granularity.

Virtual Water Trade and Country Vulnerability: A Network Perspective

We analyze the link between virtual water trade, that is, the flow of water embodied in the international trade of agricultural goods, and vulnerability to external shocks from the vantage point of network analysis. While a large body of work has shown that virtual water trade can enhance water saving on a global scale, being especially beneficial to arid countries, there are increasing concerns that more openness makes countries more dependent on foreign food suppliers and especially more susceptible to external shocks. Our evidence reveals that the increased globalization witnessed in the last 30 years is not associated with the increased frequency of adverse shocks (in either precipitation or food production). Furthermore, building on recent advances in network analysis that connect the stability of a complex system to the interaction between the distribution of shocks and the network topology, we find that the world is more interconnected, but not necessarily less stable.

Cambiamento climatico e commercio di acqua virtuale nel Mediterraneo

Cambiamento climatico e commercio di acqua virtuale nel Mediterraneo In questo lavoro viene considerato lo scambio virtuale di acqua tra Paesi del Mediterraneo, che fa riferimento al contenuto implicito di acqua utilizzato per la produzione di beni commerciati. Vengono stimati i flussi di acqua virtuale legati al commercio di beni agricoli, e successivamente, viene impiegato un modello di equilibrio economico generale per simulare gli effetti di una minor disponibilita futura di risorse idriche, legata al cambiamento climatico. Viene valutato come e quanto i meccanismi autonomi di adattamento dei sistemi economici possano costituire una parziale risposta ai problemi di riduzione delle risorse idriche disponibili.