Re: Simulating Individual Behavior

[Daniel J Shapero]

hi,
        this is my first message to the group.  I have been reading the
dialogue for about two weeks and feel that something that happened to me
yesterday pertains to Dougs message about parameters and conditions of
models.  I am an undergraduate at Johns Hopkins working on a Buffer Stock
Model for a professor with Todd Allen.  After getting the program to work
(in SWARM) and the the GA values to converge to specific values, we showed
the program to the overseeeing prof.  he said that our values were all
wrong.  Todd and I then looked at the model and realized that we took into
account something that the professor did not.  Our agents adopted rules
that had good average utilities, but also the length of time over which
that rule was successful was important... a good rule for 10 years was
better than one for 2 years.  This parameter definately mimics life.  But
me realized that we did not know which should be more important to the
agent, length of duration or actual average utility.  So how did the
professor get an answer... he did not take length of time importance into
account when deriving the analytic answer.
once we eliminated that part of the adoption rule, the converged values
were correct.  
        
        The moral is that I thought that the most interesting part of the
experience is that ABM(IBM, OBM, whatever) can be used to do parameter
sweeps over the importances of length of rule v. average utility over that
time.  This sweep would derive a pretty picture of a fitness landscape in
another variable...  Then these new results could be compared to data(if
there is any out there).  On the other hand, this macroeconomics professor
is not interested in these other mechanisms, the ones i feel are most
interesting.  It is going to be interesting how these results are going to
be published (ABM along side MAcroeconomics)  Macro using SWARM.  I love
it!!!

hope you didn't mind my jump into the group,
Daniel Shapero

ps. doug, i like your quote at the end of your messages



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