Attractiveness Multiplier, does it matter?

This forum contains all archives from the SD Mailing list (go to http://www.systemdynamics.org/forum/ for more information). This is here as a read-only resource, please post any SD related questions to the SD Discussion forum.
Locked
"Jay W. Forrester"
Senior Member
Posts: 63
Joined: Fri Mar 29, 2002 3:39 am

Attractiveness Multiplier, does it matter?

Post by "Jay W. Forrester" »

George Richardson wrote, regarding the formulation of multipliers in
"Urban Dynamics."
>My bet would be the more multipliers in the formulation, the LESS
>volatile it (the value of the product) becomes. There would be
>myriad feedback effects that would actively compensate for extreme
>values and keep the product more or less in check.
>
>One could check this in Urban Dynamics, I would think.

One can go much further and ask, "Do any of the comments and
suggestions about how to handle the multipliers really make any
difference? The test should be not to argue, as an isolated
question, about small variations in the table functions or how they
are combined. Instead, one should start by showing in what way a
change in the model assumptions would change the policy
recommendations that emerge from the model.

Are there any changes in the formulation that would invalidate the
direction of policy consequences in Chapter 5 on Urban Revival? I
stress the "direction" of change and not small variations in
magnitude of change. In other words, which policies have high
leverage, and in what direction should we be trying to change them?
Unless a plausible proposed change in the multiplier representation
can be shown to invalidate the policy implications, then the
differences in representation are not important.
--
---------------------------------------------------------
Jay W. Forrester
From: "Jay W. Forrester" <
jforestr@MIT.EDU>
Professor of Management
Sloan School
Massachusetts Institute of Technology
Room E60-389
Cambridge, MA 02139
Locked