Sam Cole

Long-term forecasting methods: Emphasis and institutions☆

Abstract There are many explanations why the more structured and formalised techniques of forecasting have not yet provided major input to government policy except in specialised areas. This article gives an assessment of the present state of the art in our ability to predict the consequences of current actions in the long-term future. The relevance of this to the ongoing debate about the place of formal methods in policy analysis is considered. In many instances it seems that the methods used run counter to the ideal of scientific liberalism to which the forecasters and officials involved often subscribe. The article indicates where institutional arrangements can be adjusted to ensure that the forecasting ability available is better employed, and points to areas in which forecasting methodologists should increase their attention if forecasting methods are to support more open and more flexible institutional arrangements.

Models of world food supply, demand and nutrition☆

Abstract Computer simulation of the world problematique offers a policy maker an interesting opportunity to see the dynamics of relationships within and between the global subsystems of which food and agriculture is one. The four major modelling studies reviewed in this article make assumptions about the possible level of food supply, technological and economic impacts on production, ecological consequences, and social and political factors influencing demand. Following their analysis of agricultural data inputs in all these areas, the authors discuss the type of policy measures likely to be recommended on the basis of global modelling.

Long-term forecasting in Western Europe☆

Abstract In the last decade several investigations into the scope of forecasting activities in Europe and elsewhere have confirmed that there is an increased awareness of the need for forecasting both inside and outside government. The focus of this comparative study is the practice of long-term forecasting in Western Europe and its contribution to social and economic planning. National planning systems, their objectives, institutional frameworks, and methods employed are examined. The appendix gives a country-by-country description of forecasting in the EEC, and outlines activities in Eastern Europe, Japan and the USA.

Models, Metaphors and the State of Knowledge

Policy analysts are often troubled by the lack of attention paid to their work and to the harsh critique which it sometimes encounters. This is especially true of systems modellers and those making use of the more sophisticated analytic techniques of the policy sciences. Several of the papers from the present seminar on Systems Analysis in Urban Policy and Planning indicate the doldrums, and even disrepute that modellers feel. In the present paper I shall explore this issue and ask to what extent the concern is legitimate, or whether it is not in some ways misplaced. I will argue, for example, that criticism is inevitable, given the social role of policy-oriented systems research. I will be concerned most directly with the use of large-scale models, drawing on my own experience in long-range forecasting and urban planning research.

Towards a Model for Long-Term Education Policy.

Abstract This paper describes the long-term economic and demographic forecast from recent long-term computer global models and discusses their possible relevance to education policy. Overall, regional, sectoral and international economic results are described as well as age and skill specific demographic results. It is argued that the models may be of some value in their current form but that a more comprehensive and value based analysis is in order. Different Utopian models of education, traditional, diverse and planned, and their dysutopian counterparts are sketched. After taking one of the current models as an illustration, a computable quantitative framework, designed to overcome several of the criticisms of current models made in the paper, is suggested.

Description and Results of the Studies

This chapter presents the studies on various models. The Limits to Growth model was constructed using a technique called systems dynamics. In this method, much emphasis is placed on the structure of the system considered and the dynamic nature of relationships. The second major global modeling project to have received a high level of support from the Club of Rome is the Strategy for Survival model. The work was carried out mainly at Cleveland University in the United States and Hanover University in the Federal Republic of Germany. Another model named the Latin American world model is reported to be constructed at the Fundacion Bariloche in the Argentine. It originated largely as a third world reaction against the conclusions of the Limits to Growth and similar studies.

Conclusions—Where Do We Go from Here?

This chapter presents the conclusions related the study of various available models and discusses the future related to it. In assessing overall global constraints it is evident that world modelers have moved away from the doomsday thesis of the Limits to Growth modelers. However, the idea of economic and social collapse is certainly not entirely dismissed and especially not at the level of the poorest regions. In this, the most depressing conclusions come from the food sectors of the model. One major advantage of the modeling method in general given by modelers is the explicitness of assumptions. Assumptions about the future described by the basic structural assumptions of the models often reflect fundamentally opposed and essentially untestable ideological positions. Differences of ideology are likely to remain. For this reason alone, any idea of building a single general model to test all alternatives must be suspect. Far more useful debate is likely to come from comparing the result of alternative models and their underlying assumptions.

Comparison of the Model Results

This chapter presents the comparison of model results. It presents a comparative analysis of the results of the models and of the method employed. One of the important items to focus on is the relative per capita economic growth rates of different world regions, forecast by the models when the measures advocated by the modelers are introduced. To understand in detail, why the models produce different results, requires a rather close examination. In part, results are determined by the explicit normative goals set for the models. On balance, the models do not differentiate well between different ways of transferring income between countries. They cannot evaluate the relative merits of aid versus commodity price increases; however, they are introduced and certainly do not attempt to calculate the impact of stockpiles or other devices designed to eliminate short-term fluctuations or for strategic purposes.

Methodological Considerations—The Limits to Modelling

This chapter discusses the assessment of the methods of modeling. Unlike the modelers of the Limits to Growth, the UN modelers have attempted to build a much disaggregated model displaying many sectoral and regional divisions. The UN model is an extension of the traditional form that usually deals with single country inter-industry flows. Firstly, it has a very high level of disaggregation, secondly it includes novel variables such as the output of pollutants and the inputs of physical resources, and thirdly it employs some nonlinear relationships. Its application to long range planning and to estimation of trade relations is also less common. The criticism of optimization models by the modelers of the Limits to Growth is that they may be highly sensitive to small parameter changes. To a proponent of optimization this provides a reason for a formal maximization method.