Simulation of food and agriculture

Conferences

Si mulation of food and agriculture The third 22-25

IIASA

September

symposium

on global

The symposium, one of a series sponsored by the International Institute for Advanced Systems Analysis, was attended by some 60-70 delegates with the USA, Western and Eastern Europe well represented, but with few delegates from the developing countries. Early on in the proceedings there appeared to be a division between those familiar with farm practices and the theoreticians, showing itself as an optimist/pessimist split. Subsequently the resolution of this difference emerged in the identification of the gap between what is physically possible with current technology, and what is practised because of socioeconomic constraints. The principle aim of the symposium was to present the work of the Dutch inter-disciplinary team led by Professor Hans Linnemann, which has culminated in the birth of MOIRA: A model of in ternational relations in agriculture. During the first two days various members of the team presented different aspects of the model. Although it is essentially a food model, with the non-agricultural (industrial) sectors entering as an exogenous input, it represents a major advance over the earlier Club of Rome models, (those of Meadows, the Bariloche Foundation, and Mesarovic and Pestel), both in its factual base and the socio-economic realism of its structure. They have produced a behavioural model of food producers and consumers with which to examine the world food situation. They hope to use the model to identify the causal factors of hunger and malnutrition and to define policy measures which will improve the food situation. Professor Linnemann outlined the main structure of the model, the core of which is referred to as the think model

FOOD POLICY

modelling

Baden,

Austria,

1975.

February

1976

of the agricultural sector. In this subagricultural sector model the endeavours to fulfil the demand for food via an income maximising pathway. Yields in the model depend on natural resources, capital and labour, and determine the required fertiliser input. The price of these inputs and the output determine the income level. Total agricultural production of field crops and livestock, including cotton, wool non-food crops are and other aggregated and expressed in terms of consumable protein. Linnemann and his colleagues explained how the choice of consumable protein as the unit of measurement of food output was based on a linear relationship between the nitrogen provided in the soil or as a fertiliser, and the amount of protein nitrogen in the biomass produced. Many of the agronomists present disputed this lack of explicit diminishing marginal returns to fertiliser, and doubted the realism of modelling output of non protein containing products like sugar and cotton by their method. Dr van Heemst reviewed the detailed study of arable land resources which has been completed for the model. Their estimate of the total arca of potentially arable land (34 19 M ha) is greater than the value used in the Meadows and Bariloche models (3188 M ha) and is considerably greater than the pessimistic estimate used in the Mesarovic and Pestel model (2425 M ha). By estimating potential gross photosynthesis in different regions, the Linnemann group have estimated the maximum food production potential of the world which, when expressed in grain equivalents, is equal to forty times the current output. Although they made it clear that this was a theoretical

maximum, which in practice would be reduced by agronomic and economic constraints. this very high asymptote provoked heated discussion. Professor Linnemann and Dr Keyser in their respective presentations outlined some of the socio-economic constraints which are represented in their model. Thus it considers how there is a conflict of interests between the agricultural and nonagricultural population, ie the farmer wants high prices for his products and the nonagricultural population wants low ones. World prices of food in the model influence domestic ones, which in turn can be affected by subsidies. Furthermore the model reflects how in food importing countries, low world prices tend to reduce domestic food prices and hence favour the non-agricultural, but adversely affect production and income growth in the agricultural sector. Professor Linnemann explained how food demand is based on purchasing power, and how they have introduced income distribution. In the model very poor people spend all of their resources (money or labour) on food consumption, namely on low value, low protein foods, which echoes reality. At medium and higher incomes the mix becomes greater. but because of the lack of disaggregation in food output in the model it is not possible to determine whether the richer people are eating meat or peanut butter, and this is one of the less desirable characteristics of the model. The model has only just been completed, and therefore the results presented by Professor de Hoogh were of a preliminary nature: nonetheless they stimulated a lively discussion. The results suggest that given present income distribution, population growth at

Conferences the UN medium rate, together with modest growth in GNP, nutritional standards may deteriorate in many areas of the developing world. Unlike the Mesarovic and Pestel model, the Dutch estimates of future low food intakes were not influenced to any marked extent by different assumptions of population growth rates. The remaining papers fell into two one consisting of main categories, reviews or studies on large scale computer models, and the other of descriptive or relatively simple models. Professor Bottomley presented details of Bradford University’s data bank of input-output tables, and described how these might be linked together to produce a world agricultural model. He went on to suggest that knowledge of the input-output coefficients of the different agricultural sectors in specific LDCs could be used to identify those areas which would benefit most from foreign aid. Donella Meadows briefly described the Dartmouth Systems Dynamics group’s present survey of agricultural development models in LDCs. She explained how they are trying to express such models in a common format so that policy makers might readily understand them, and be able to compare and evaluate them. Dr Richardson gave a very lucid summary of the Mesarovic and Pestel model, and went on to echo Donella Meadows’ concern for the need to establish a relationship between model builders and policy makers. He reported on the Mesarovic and Pestel groups’ recent efforts to explain their model to policy makers in Iran, Venezuela and the EEC amongst others, and to show them how such models could aid the decision process. Professor Gallopin presented two papers, one summarising the food sector of the Bariloche model which had been presented at the second IIASA Symposium in 1974, and the other on sensitivity analysis. Model builders are commonly obliged to use parameter may be erroneous, which values because the data or methodology are inadequate to determine these values prepotential cisely, eg the maximum agricultural yield. It is therefore important that modellers test the sensitivity of their models to the likely range of errors

in these values, so as to ensure that they do not markedly affect the validity of the model output. Professor Gallopin described how they had subjected their tests, and had model to such demonstrated its insensitivity to small of certain changes in the value parameters. Dr Norse outlined a method for defining the relationship between food energy intake and mortality, and applied it to a simple model of future food production in India, Bangladesh and Pakistan. The model suggests that given poor economic growth and the present wide distribution of income and hence of food intake, annual deaths from starvation in Bangladesh may reach

5

million

by

the

year

David Norse, Systems Analysis Research Unit, Department of the Environment, London, UK.

2010.

given steady economic growth food production could be sufficient to prevent such widespread starvation. Professor Kaya related the problems they had met with multi-sector, multiregion normative world models, and went on to describe their present work on a simpler, more aggregated model. Professor Thissen presented an analysis of the agricultural sector of the Meadows model and showed how certain relationships could be left out of the model without markedly altering the standard run behaviour of the model. The buffer stock concept has been discussed widely in recent times, and one paper was given on this theme. Professor Kamrany presented his proposal for an International Food Fund, which would provide emergency food requirements to deficit countries and/or act as a buffer stock. He briefly described a study on the agricultural potential of the Sahel-Sudan zone, and went on to show how the fund might operate in this region, the possible size of the stock and its cost. The papers of Etienne, Sanderson and Weber, all pointed to the large potential which exists in developed and developing countries for technological improvement both in the use of land and in the use of production inputs. In the final paper, Dr Rossmiller gave a general description of global and national modelling techniques and their use for examining policy options. He ended his paper with a plan for international co-operation to bring together the expertise and data to build better systems models. However

The Symposium concluded with two discussion sessions. The general consensus was that neither resources nor technological constraints were likely to be the primary limitations to expanding world food production over the next 25 years or so. Thus most delegates believed that socio-economic problems would be the most important limiting factors. However Dr Sen surprised most of those present with his view that inwere not constraints stitutional necessarily a major limitation to the expansion of food production in India.

Papers presented at the third IIASA posium on global modelling: Food and agriculture models

sym-

MOIRA: a model of international relations in Linnemann and agriculture, H. Associates. A world agricultural model: an input-output research proposal, J.A. Bottomly A hierarchical multination link model for development planning: balanced development between agriculture and industry, Y.

Kaya Food submodels

of world models:

World 3, Donella Meadows Latin American model, G.C. Gallopin Problems of food production in certain Asia countries, D. Norse Pestel/Mesarovic, J. Richardson Generalproblematique: Grain demand, supply and trade projections to 1985, F.H. Sanderson International food fund concept, N.M. Kamrany Food problems and international trade in cereals, G. Etienne

Methodological problems: World 3 agricultural model summary, W. Thissen Global modelling of food and agriculture: background to a possible approach, E. Rossmiller Modelling food production: review and assessment of various approaches, A. Weber Papers available presented:

at the symposium

but not

Agrimod: a policy analysis of US food production, A.H. Levis, S.M. Haas, E.R. Ducot, D.G. Luenberger and E.R. Larson. Common agriculture: policy and practice, G. MacKerron and H. Rush. India’s prospects for self-sufficiency in food grains, Bandhudas Sen. Models of world food supply, demand and nutrition, J. Clark and S. Cole.

FOOD POLICY

February

1976

Future of European agriculture The first European conference of agricultural ~~~sa~a, Sweden, 25-29 August 1975 In August 1975 European agricultural economists met to establish a basis for a continuing Association and to participate in discussion of matters of professional concern. Representatives from 24 European countries, from the Commission and Council Secretariat of the EEC, from OECD and FAO were present, some 240 people. The meeting approved a constitution which establishes The European Association of Agricultural Economists. It is envisaged that this will act as a regional grouping of the world body, Association of The International Agricultural Economists. Officers and an Executive Committee were elected to carry on the affairs of the new Association and provision made for the collection of membership fees. These details of organisation are important in assessing the potential of the newly created institution. They mean that the Association will be paneuropean rather than Western European. They make it essential that a political as well as a professional balance is achieved in the programme and in the appointment of office bearers. As a long-term project this may prove an advantage. Dialogue between economists from centrally planned and market economies is in present circumstances frustrating and sterile. We do not share the same criteria about what is ‘an improvement’ nor do we have at our disposal the same instruments of policy in attempting to change existing tendencies. Nevertheless, we may have something to learn from each other about the way in which we handle problems which are common to us all. At a purely human level the opportunity to meet and discuss helps to create a more relaxed and constructive framework for our dialogue. The disadvantages of paneuropean arrangement are not negligible. The cost of travel across the whole of Europe may make participation by younger professionals more difficult. It is hoped to remedy this by holding smaller regional meetings as well as occasional general assemblies. There are some issues of concern to

FOOD POLICY

February

1976

economists,

countries in Western or in Eastern Europe upon which it may be hard to sustain high level professional discussion if at the same time there has to be a political balance between East and West. Again it is hoped that regional meetings may be a means of diminishing this difficulty. If they do not, then there may be pressure for some alternative form of association. The theme of the Conference Future development of agriculture in Europe - prospects for the 1980s reveals something of the broad basis of professional discussion. The theme was discussed in four sections each introduced by a paper: Changes in society and the general economy (Professor J. Stanovnik, Yugoslavia); Technological and biological changes in agriculture (Professor G. Steffen, Germany); Changes in the relationships between agriculture, the food industry and trade (Professor G. Allen, UK); and Structural changes in agriculture (Professor D.R. Bergmann, France). Each author except Professor Steffen who was ill, presented his paper, which was then subjected to comment and questioning by two appointed ‘interlocutors’. A brief general discussion followed. The conference then divided into six groups, which were in

turn sub-divided into ‘beehive groups’ of about six participants. Within each ‘beehive’ discussion took place and a report was made, these formed the basis of reports by the group rapporteur to the plenary session. The effect of this system was that people who attended the conference actually took part in discussion and many had an official or semi-official role in its activities. The very general subjects allotted to each speaker succeeded in stimulating discussion. The authors, although making a valuable contribution to understanding by drawing together many relevant aspects of their topics did not have the opportunity to do much more than pose the important questions. Understandably they did not attempt to offer any new solutions. Discussion tended to focus on particular aspects of the subjects and reflected the differing standpoints of participants on whether. for example, the large farms of some East European countries were justified by purely economic criteria or again whether we were witnessing in present world instabilities a ‘crisis of capitalism’. It would be an exaggeration to suggest that in formal terms the subject had been greatly advanced by this meeting. However, because so many took part in discussion and because all learnt more about how other economists see their problems, the meeting may well have helped to stimulate fresh thinking from which, in time, better solutions to current problems may be attained. J.S. Marsh, Department ofAgr;culfura/ Economics, University of Reading, UK.

Books ENERGY AND AGRICULTURE THE THIRD WORLD by Arjun

~akhijani

IN

in collaboration

with Alan Poole 168pages, John

Wiley

for Ballinger,

1975,

f2.00

& Sons,

paperback. Chichester,

Cambridge,

UK

USA.

In spite of considerable efforts to encourage development over the past two decades, the results, with certain notable exceptions, have been disappointing, and the gap between the developed and

developing countries has increased over this period. In developing countries, the greater part of the population, typically 80%, lives in rural areas and it is in these areas that development has been least effective. Energy is one of several essential components necessary for development. Most of the developing countries lie between latitudes 30’N and 30”s. Most of these countries are poor in energy and the import of oil and other energy supplies makes a heavy drain on their foreign exchange. On the other

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