Tag Archive for 'Forrester'

A Dynamic Synthesis of Basic Macroeconomic Theory

Published on August 4, 2011 in Economics, Structural analysis, Thesis and Vensim. 0 Comments Tags: Economics, Eigenvalue, Forrester.

Model Name: A Dynamic Synthesis of Basic Macroeconomic Theory

Citation: Forrester, N.B. (1982) A Dynamic Synthesis of Basic Macroeconomic Theory: Implications for Stabilization Policy Analysis. PhD Dissertation, MIT Sloan School of Management.

Source: Provided by Nathan Forrester

Units balance: Yes, with 3 exceptions, evidently from the original publication

Format: Vensim

Notes: I mention this model in this article

~~A Dynamic Synthesis of Basic Macroeconomic Theory (Vensim .vpm)~~

Update: a newer version with improved diagrams and a control panel, plus changes files for a series of experiments with responses to negative demand shocks:

Download NFDis+TF-3.vpm or NFDis+TF-3.zip

The model runs in Vensim PLE, but you’ll need an advanced version to use the .cin and .cmd files included.

Market Growth

Published on November 22, 2010 in Business, Published and Vensim. 0 Comments Tags: behavior, bounded rationality, Forrester, Morecroft.

John Morecroft’s implementation of Jay Forrester’s Market Growth model, replicated by an MIT colleague whose name is lost to the mists of time, from:

Morecroft, J. D. W. (1983). System Dynamics: Portraying Bounded Rationality. Omega, 11(2), 131-142.

This paper examines the linkages between system dynamics and the Carnegie school in their treatment of human decision making. It is argued that the structure of system dynamics models implicitly assumes bounded rationality in decision making and that recognition of this assumption would aid system dynamicists in model construction and in communication to other social science disciplines. The paper begins by examining Simon’s “Principle of Bounded Rationality” which draws attention to the cognitive limitations on the information gathering and processing powers of human decision makers. Forrester’s “Market Growth Model” is used to illustrate the central theme that system dynamics models are portrayals of bounded rationality. Close examination of the model formulation reveals decision functions involving simple rules of thumb and limited information content. …

Continue reading ‘Market Growth’

Urban Dynamics

Published on June 14, 2010 in Economics, Published, Social and Vensim. 1 Comment Tags: Forrester, urban.

This is an updated version of Urban Dynamics, the classic by Forrester et al.

John Richardson upgraded the diagrams and cleaned up a few variable names that had typos.

I added some units equivalents and fixed a few variables in order to resolve existing errors. The model is now free of units errors, except for 7 warnings about use of dimensioned inputs to lookups (not uncommon practice, but it would be good to normalize these to suppress the warnings and make the model parameterization more flexible). There are also some runtime warnings about lookup bounds that I have not investigated (take a look – there could be a good paper lurking here).

Behavior is identical to that of the original from the standard Vensim distribution.

Urban Dynamics 2010-06-14.vpm

Urban Dynamics 2010-06-14.mdl

Urban Dynamics 2010-06-14.vmf