The Agora, is a economics simulation environment, for
studying such phenomena as the emergence of money from 
a barter economy. The Agora is written in Smalltalk
by KevinLacobie.

See ''Computational Modeling of Social Learning Project Report''
for sample results.

From the introduction of this paper we learn ...
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The purpose of this project is to create a "primordial soup"
with only a few fixed parameters from which economic behavior may
emerge.  Agents learn what to produce, who to trade with, what to trade
and how much all at the same time.  Knowledge of any of these enables
knowledge of the others, so that division of labor, money, social
networks of trade, ideal types, prices and production efforts all push
each other in positive feedback, just as the first life self-organized.
As these things push each other, society goes through stages from
individual production of most needs to barter of a few goods, to barter
of many as their trade networks mature.  The fuel behind this self
organization is not natural selection, but symbolic interactionism.  As
agents read and display signs, the structures of society unfold.  They
socially construct their world through their schema: through
self-fulfilling prophecy they form ideal types.  Even though natural
selection was used as the inductive method on a lower level of
description, the higher level symbolic interactionism  is a method of
self organization which is distinct from natural selection, is more
cooperative does not depend on death.