In the national economic planning of the GDR, input-output models are used to analyze and to calculate the extent of structural changes within the national economy. Both aggregated and more detailed input-output models are used, depending on the specific application. One of the more aggregated models contains 18 sectors (groups of products) and is used primarily for long-range calculations. A more detailed model containing about 600 entries
(partly in physical terms) and 16 ministries is mainly used for one-year cal- culations (for details, see M h l e r et al. 1981).
The structure of these input-output models and their possible applica- tions are well known. Currently, the major uses in the GDR are to facilitate the supply of economic data, the planning of technical coefficients, and the planning of structural changes within sectors. In the field of plan calcula- tions the most important present task is the calculation of the courses of different structural changes with various objectives. The central question remains the planning and forecast of structural changes in industry, which is the leading and largest sector of the national economy. (The share of industrial production in the gross material product of the GDR was 72 percent in 1981 and even more in subsequent years.)
The common goal of the plan calculations is to ensure a steady rate of economic growth in the GDR, as measured by the growth rates of national in- come or final product, against a background of generally constant or in some cases even declining resource bases. Steady economic growth is the vital precondition for a gradual yet guaranteed increase in the material and cultur- al living standard of the people. The main way to achieve this end is to harness the latest developments from science and technology, which are the most important determinants of change in the production structure. The need for structural changes is also created by changes in the requirements of the people and the state, changes in the availability of resources within the national economy and on the world market and the consequences of man's inter- action with the environment. Finally, changes in the international division of labor and in the structure of world trade also cause significant changes in the domestic production structure of the GDR. All these factors (see Figure 1) act simultaneously and of course interact with one another. The effects on the structure of production differ, both in material consequences and over time.
The objectives deduced from these complexes of causes can differ from one another, but they can also be identical in some cases. For instance, the use of achievements of technological progress is directed toward such ends as saving existing resources, increasing the output of new resources, better satisfying the needs of the people, or increasing the quality of exported goods. The changing requirements of the people demand new articles, services,
Requirements
n
.
.Production
1
FIGURE 1 Causes of structural changes.
and results from science, and techniques, for instance, to facilitate house- work. Changes in the availability of resources evoke processes that can substitute some kinds of energy or raw materials by others or that lead to a higher quality of metals and plastics, thereby reducing the specific con- sumption of metals in the national economy. Finally, changes in the struc- ture of world trade require new products of a very high technical standard, for example, incorporating a high degree of automation or with very low specific consumption of energy.
In order to meet all these objectives, economic calculations of struc- tural changes are necessary. First of all, it is necessary to calculate all the expenditures implied and the likely results of such structural changes.
These calculations are partly performed using input-output models, which have to be adapted to the purpose of the calculation, especially in terms of classification and model structure. For these calculations, input-output models and the use-value and value input-output table with entries in natural units are better suited than others. Many detailed structural changes are not reflected adequately by aggregated input-output models. This does not mean, however, that aggregated input-output models are not used at all for analyzing structural change. In the GDR the influence of structural changes in the requirements of the people on changes in the structure of material consumption and resources has been analyzed using the statistical, 118-sector input-output table. To describe the structural changes in requirements in more detail, the consumption term in the final product was divided into so- called "complexes of needs", such as food, clothing, housing, health, trans- port, and others. Changes both between and within these complexes of needs have their own particular effects on resources, but there are also common features: for example, they all require more energy. For further information see Heinrichs and Knobloch (1983).
Calculations of structural changes must also take into account that there are no alternatives for a considerable number of these changes, above all in industry; in other words, on the basis of existing conditions, special structural changes must be implemented. Examples of this can readily be found:
for instance, the substitution of oil by other kinds of energy (in the GDR,
TABLE 2 Currently important directions in science and technology. energy and raw materials. The GDR belongs to that group of countries that find it necessary to import a great amount of energy and raw materials. Therefore,
Intermediate products
Secondary raw materials
Final product
n
Degree o f utilization (recycling)
FIGURE 2 Incorporating recycling in macroeconomic input-output models.
Source and detailed model: Sagert (1981).
specified waste products per unit of production or consumption, (b) the uti- lizable secondary raw materials per unit output of waste products, and (c) the use of secondary raw materials per unit of production (a very simplified scheme is shown in Figure 2). The practical implementation of this idea would need extensive and detailed information, and at present we do not have all the necessary data. Moreover, note that the raw material consumpti.on of each raw material entry in the input-output table would have to be sub- divided into three shares, corresponding to inland primary, inland secondary, and imported raw materials.
The examples described above show that calculations of structural changes require input-output models with detailed entries in both value and physical units, taking into account the specific purpose of each calculation. There- fore, in the GDR, the continued improvement of the use-value and value input- output table will play a decisive role in the future development of input- output models. New and more detailed entries, as well as a representation of the process of reproduction of capital stock, will be included in future work and optimization tests of the model are currently underway.
REFERENCES
Heinrichs, W. and Knobloch, G. (1983). Konsumtionsmittelproduktion und ttbergang zur intensiv erweiterten Reproduktion--theoretische Probleme.
Wirtschaftswissenschaft (Berlin), 7:961-983.
KHhler, G., Fulle, H., and Pinkau, K. (1981). Materielle Bilanzierung.
Berlin, part 5.
Sagert, J. (1981). Probleme des Zusamenhangs von intensiver Nutzung der naturlichen Ressourcen and Urnweltgestaltung. Wissenschaftliche Zeit- schrift der Hochschule fur Ukonomie 'Bruno Leuschner', Berlin, 3:63-69.