Hi Geamoro
It is a very gereral question. To build such a model, the best way is to use the Reality Checks.
Is you do not know to build models with Reality checks, go to the Chapter 14 of the user guide and study it carefully.
Then start with a simple phrase: What in particular should the behaviour of the model look like, to make it credible?
Write it down in plain english.
For example: If a new law is decided, it should accumulate to the stock of existing laws.
This sounds evident, but it will give you the occasion to start with the stock of existing laws and to build the rate of new laws entering that stock.
The interest is that with a lots of evident reality checks you will build progressively a model that otherwise would be not evident at all to build.
Write the reality chek equation in the model and then build the equations that satisfie the check. Run the model and verify that it satisfies the check and study the result that will be totally weird because it satisfies only a tiny part of what you would like.
Then after a while, write down always in plain english a second reality check, build the reality check equation in your model, then the equations that satisfie the RC and so on.
To see the interest of Reality checks read the pdf file joined.
The file is too big to be uploaded.
You must go to
http://www.systemdynamics.org/forum/vie ... ?f=13&t=97
and try to dow load the third file about Reality checks from Peterson and Eberlein.
You may need to have a membership of the system dynamics society.
Otherwise Bob may give you some way to dowload it.
Another way is to send me your e-mail so that I can send the file to you directly or enter you e-mail adress in your personnal forum settings.
Regards.
JJ
[Edited on 30-10-2010 by LAUJJL]
[Edited on 30-10-2010 by LAUJJL]
[Edited on 30-10-2010 by LAUJJL]
[Edited on 30-10-2010 by LAUJJL]