Re: Modelling PK / Eco Systems using Stella Software?

[James Juniper <James.Juniper@xxxxxxxxxxxx>]

Dear Eric,

I have been working with VisSim for some time now, and colleagues such as Steve
Keen and Trond Andresen routinely use Simulink-Matlab's software suite for
modeling dynamic systems. This mathematical and engineering-based software is
more formal than Stella, which employs a graphical and iconic approach with a
mathematical under-belly. Each have their advantages, the former supports
standard tools such as Bode charts and Nyquist diagrams for the analysis of
transfer functions (Laplace transforms of systems of differnetial equations)
and can incorporate Matlab routines and advanced control functions. The latter
has the advantage that it doesn't scare away prospective students who do not
possess a strong maths background. Check out Trond's and Steve's papers on the
Post-Keynesian Archive. I've done simulations of the usual limit-cycle models
such as Kaldor's investment cycle model if you're interested.

Cheers,

James

-----Original Message-----
From: Eric Miller [mailto:ewmiller@xxxxxxxx]
Sent: Tuesday, 28 January 2003 14:57 PM
To: PKT List (E-mail)
Subject: Modelling PK / Eco Systems using Stella Software?


Hi PKT folk,

I'm playing around with "Stella" software, which is a tool for graphically
modelling systems with their stock, flow components, etc.  I'm exploring its
usefulness in topics related to economic-ecosystem interactions.

Do any of you have Keynesian models of the economy in Stella format, onto
which I could add some ecological or environmental interactions?  Or
anything similar?

Keynesian and PK thinking seems very systems-based, though I have trouble
finding explicit Keynesian systems models on Stella (or similar software).
There is one I found that examines the accounting of debt, deficits, tax
cuts, and US social security, but that's all I've come across so far.  (I
think Wray, Mosler and others might find the storytelling features within
Stella as very useful tools to visually explain their ideas on public
budgeting, etc)

Cheers,
- Eric