Global food demand,productivity growth,and the scarcity of land and water resources: a spatially explicit mathematical programming approach

In the coming decades, an increasing competition for global land and water resources can be expected, due to rising demand for food and bio‐energy production, biodiversity conservation, and changing production conditions due to climate change. The potential of technological change in agriculture to adapt to these trends is subject to considerable uncertainty. In order to simulate these combined effects in a spatially explicit way, we present a model of agricultural production and its impact on the environment (MAgPIE). MAgPIE is a mathematical programming model covering the most important agricultural crop and livestock production types in 10 economic regions worldwide at a spatial resolution of three by three degrees, i.e., approximately 300 by 300 km at the equator. It takes regional economic conditions as well as spatially explicit data on potential crop yields and land and water constraints into account and derives specific land‐use patterns for each grid cell. Shadow prices for binding constraints can be used to valuate resources for which in many places no markets exist, especially irrigation water. In this article, we describe the model structure and validation. We apply the model to possible future scenarios up to 2055 and derive required rates of technological change (i.e., yield increase) in agricultural production in order to meet future food demand.     

The IMF’s adjustment concept

Both creditor and debtor countries ascribe an important medium-term role to the International Monetary Fund in tackling the debt problem. What possibilities are there for the IMF to exert influence and what use does it make of them?     

The world economy still at risk

Following the prolonged upswing in the world economy during the eighties, the subsequent downturn is proving to be more persistent than expected. It looks as if the USA is now at last on the road to recovery but Japan and Western Europe are still having a tangible dampening effect at the turn of the year. Are there prospects for an improvement in the world economy for 1993?     

Transition strategies for the forest sector

Because of limited wood resources the Scandinavian forest sector will soon have to make the transition from rapid to slow industrial growth. This will mean increased wood prices, excessive removals, increased centralisation, and reduced employment. The authors discuss the strategies available to cushion the effects of the transition, and the factors that should be taken into account when choosing a strategy. Their conclusions are based on a computer model which enables possible developments in the forest sector over the next 30–50 years to be simulated quickly.     

Transferability of integration models

The establishment of a Common Market in Europe encouraged many of the less developed countries (LDCs) to model their own efforts at integration on similar lines. Only gradually did doubts begin to be expressed about the advisability of unquestioningly adopting the European model.