International Encyclopedia of Systems and Cybernetics

Very global models aiming at forecasts of planetary long term trends in demography, ecology, economy and social evolution.

Around 1970, the Club of Rome, using J. FORRESTER's systems dynamics in its most general form ("World Dynamics"), started a series of world models, which were heavily criticized for methodological, ideological and socio-political reasons.

Already in 1974, E. LASZLO stated: "Because the world is a highly heterogeneous system, with multiple hierarchic levels and a large number of relevant variables, constructing a detailed global structure is a colossal task" (1974, p.124). So it indeed proved to be.

As to the methodology, and in a very general frame, G. KLIR writes: "As a rule, genuine systems problems are computationally extremely difficult. They are often made tractable by overly strong simplifying assumptions that are usually not stated. The resulting methods can than deal with sizable systems emerging from practical applications and produce "impressive" results, but the significance of these results is questionable at best" (1993, p.50).

The relative failure of world models somewhat discredited systems views in general and G. KLIR thus adds: "Such methodological dishonesty is contrary to the spirit of systems science. The latter is not interested in producing immediately marketable methodological tools at the cost of convenient simplifying assumptions whose validity is dubious, but rather in pursuing basic methodological research involving genuine systems problems" (Ibid).