I'm enjoying this discussion. Regarding the 2001 symposium Scott
mentioned, I just wanted to clarify that KEITH Sawyer was one of the
co-authors (not Malcolm Sawyer). Citation:
Conte, R., Edmonds, B., Moss, S., & Sawyer, R. K. (2001). Sociology and
social theory in agent based social simulation: A symposium.
Computational and Mathematical Organization Theory, 7(3), 183-205.
Scott Moss wrote:
>All of the responses so far to my posting seem to me to raise
>interesting and valid points. Some years ago on this list we had a long
>discussion about modelling top-down or bottom-up. The modelling
>elements of that discussion were reported as a symposium among Rosaria
>Conte, Bruce Edmonds, myself and Malcolm Sawyer in CMOT. I don't want
>to revisit the same discussion.
>
>So can we stipulate that SD is a sort of top-down modelling approach
>with a static representation of social structure and no direct
>representation of interaction among socially embedded individuals?
>
>Nearly 10 years ago, Van Parunak demonstrated that for a particular
>social target an SD model yielded different results from those of an
>agent based model. As I remember, Van ascribed the difference to the
>effect of agent interaction.
>
>I am not aware of any general results in this vein.
>
>If the result were general, then we could define the domain of
>application of SD social models as the set (or a subset) of cases where
>social interaction among individuals does not affect the macro level
>outcome. Similarly, the domain of application of agent based models
>would be where social interaction does affect macro level outcomes.
>
>If it is possible to capture agent-based macro level results with an SD
>model, then there might well be efficiency gains in using such a model
>where scaling up the number of agents is computationally too expensive
>with available technology. For this to be a reliable procedure, we
>would need some general results about -- or experience with -- the
>conditions in which macro level outcomes can be represented as if they
>did not emerge from social interaction.
>
>What is not true is the remark that stimulated my original posting. It
>is false to say that system dynamics is the modelling method of choice
>for social systems. You can only have confidence in its applicability
>where there is no effective social interaction among individuals and the
>social structure is static.
>
>
>
--
R. Keith Sawyer
Associate Professor
Washington University
Department of Education
Campus Box 1183
St. Louis, MO 63130
www.keithsawyer.com
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