Numerical Methods for Analyzing World Dynamics Models.

摘要

This report is an extensive investigation of WORLD 2, the mathematical model used to forecast changes in the world's socio-economic system proposed by J. Forrester in 1971. Its purpose is to develop methods and techniques by which a rapid, facile study of other, more complicated models can be made. The significance of WORLD 2 major assumptions relative to its output are studied by devising and applying various computer techniques to the basic model and several variations of it. Standard small-scale sensitivity tests, reverse running, and scaling (inverse sensitivity tests) were among the techniques used to determine the extent of alteration necessary to produce in WORLD 2--without any structural modification--outcomes divergent from Forrester's calculations, thereby making possible identification of significant variables and sectors.