Online Content

1. Day, Richard H., "Complex Behavior in System Dynamics Models"

Type:
Document
Date Created:
1981
Collection:
System Dynamic Society Records
Collecting Area:
University Archives
Collection ID:
ua435
Parent Record(s):
23d738ba88f8333bc39725f9cb5bd0b8, 4a97153f59047c298f3bcd6b15c284f5, and e8eac154b3129692f26c222dbc2c9466
Thumbnail Path Ss:
/downloads/x633fh98s?file=thumbnail
System Modified Dtsi:
2020-01-02T18:35:11Z
Description:
Nonlinear differential equation systems of the kind used in system dynamics are capable of exhibiting highly irregular, erratic, turbulent or “chaotic” behavior. Conditions for the existence of this phenomenon are discussed and their application in dynamic socio-economic modeling explored. In particular, irregularities in economic cycles might be explained by nonlinear feedback effects in contrast to the usual “random shock” model. Dynamo simulations are used to illustrate the basic concepts involved. The view, often emphasized by Forrester, that policy should not be based on level predictions but should focus on regulating qualitative modes would seem to be strongly supported. The positive economics position associated with Friedman that theories should be judged on their predictive performance would now appear to be too restrictive. Instead, the system dynamics view that the plausibility of model assumptions should be the main basis for establishing theory credibility is strongly reinforced.