World Food System model (WFS)

The world food system model comprises a series of national and regional agricultural economic models. It provides a framework for analyzing the world food system, viewing national food and agricultural components as embedded in national economies, which in turn interact with each other at the international trade level.

The IIASA World Food System (WFS) provides a framework for analyzing—in annual steps—how much food will be produced and consumed in the world, where it will be produced and consumed, and the trade and financial flows related to such activities. For the purpose of international linkages, the production, consumption, and trade of goods and services of a country are aggregated into nine main agricultural sectors and one non-agricultural sector.

About the WFS


  • First released in 1988 at a time of global food crisis, the IIASA WFS has stood the test of time and continues to be a robust and widely used tool for rationalizing the world food system.

  • The integration of WFS with the IIASA/FAO Agro-ecological Zones (AEZ) model has formed a state-of-the-art ecological-economic modeling framework.

  • For recent applications, the WFS model has been expanded to address the issues of food vs. bio-fuel resource competition. The WFS is also regularly updated with data from the FAO.

  • The integrated WFS/AEZ system produced policy-relevant knowledge on Climate Change and Agricultural Vulnerability in the 21st Century and was used to analyze key concerns regarding Biofuels and Food Security.

IIASA released a first version of the WFS model in 1988 in response to the energy and food crisis of the1980s. The WFS model and its predecessor, the Basic Linked System (BLS), have been calibrated and validated over past time windows. Several applications of the model to international agricultural policy analysis, climate-change vulnerability, and to the food vs. fuel debate have been published.

For current applications, a state-of-the-art ecological-economic modeling framework is used that includes as two major components: the WFS model and the FAO/IIASA Global Agro-ecological Zone (GAEZ v3.0) model.

How the WFS works

The WFS is an applied general equilibrium model. Simply put, its framework is a world market based on a series of linked national and regional agricultural economic models. In these models, national food and agricultural components are seen as embedded in national economies, which in turn interact with each other through international trade. Although the WFS focuses on agriculture, non-agricultural economic activities are also represented in the model so that the essential dynamics among capital, labor, and land are captured.

Within each country/region, the model considers three groups of actors: producers (supply), consumers (demand); government (market interventions). The model recognizes the constraints of each group; however, it assumes that the actors are rational and maximize their objectives.

In this virtual representation of the market, international clearing prices are computed to equalize global demand with supply. Whatever is produced will be demanded, either for human consumption, feed, or industrial use (e.g., biofuels). Alternatively, it can be exported or put into storage. The system is balanced in annual increments simultaneously for all countries in each time period. Production in the next year is based on changes in demand and prices in the current one, making WFS a recursively dynamic system.

Based on the above, WFS gives an essential overview of the food system at the national to international levels. It identifies potential gaps and gluts in the food system, their causes, how to address them through a better use of resources, as well as any actual or potential environmental impacts caused by food production.

The WFS can identify where and when there will be gluts and gaps in food supply.


One of the main challenges confronting the agricultural sector today is to provide for various future demands from agriculture—food, animal feed, fiber, and bio-energy—without jeopardizing food production. To better understand the nexus between food security, animal feed, bio-energy, and the environment a spatially detailed understanding of alternative land use and rural development options and strategies, as provided by the WFS, is essential.

At the same time, as placing additional demand for energy biomass on agriculture, a major global effort is required to improve food production and distribution, not only against a background of expanding population and urbanization but also in the context of the current and expected effects of climate change. However, food production and distribution must also foster environmental protection and not place local livelihoods at risk. Only in this way can long-term sustainability of land and water resources be achieved.


Hunger in our world is not only related to agricultural production but to the wide geographic disparities in incomes and food availability. These often necessitate food importation to supplement or substitute for locally produced food, particularly in times of drought and local crop failure. Food, being an "inelastic" commodity, is subject to steep price fluctuations. As witnessed in recent years, this can make staple foods unaffordable, putting adequate nutrition beyond the reach of the poor. Clearly, the WFS/AEZ framework, which can advise on policy alternatives to strengthen the world food system, is an essential tool for decision makers and agricultural planners to reduce the prevalence of hunger and bring about sustainability both in agricultural development and in the use of land and water resources.

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Last edited: 29 June 2017


Günther Fischer

Distinguished Emeritus Research Scholar Water Security Research Group - Biodiversity and Natural Resources Program

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International Institute for Applied Systems Analysis (IIASA)
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