REPLY Inputs for World3-2003 scenarios (SD6844)

[SDMAIL Bob Eberlein]

Posted by  Bob Eberlein <bob at vensim.com>

Hi Jack,

The change files that comes with Vensim for the 03 World3 model actually 
correspond to the 93 version of the model (and book) - perhaps some are 
even the original book. There are 13 of them corresponding to the 13 
alternative scenarios in the earlier books.

I have to admit just from reading the most recent book I am not sure 
exactly what additional adjustments were made to the scenarios. Tom 
Fiddaman has a query out to Jorgen Randers to see if we can get the 
changes to make things line up. When that is available I will post the 
changes files on our web site.

As to the question of why nobody has noticed before, I am not completely sure. 
It is posisble, of course, that many people have noticed but not brought it
to my attention. It is also possible that those reading the book and wishing
to follow up have contacted the authors and received the supporting material
in Stella format and so have not looked at the Vensim version. It may also
simply be that the readers of the book either find the results so clear they
don't feel the need to replicate them or so unbelievable they don't see the
need to. The first edition of the book both brought a lot of attention, and 
made up a lot of minds and people are stubborn creatures. 

Bob Eberlein
Posted by  Bob Eberlein <bob at vensim.com>
posting date  Mon, 31 Mar 2008 20:45:01 -0400