By José
Manuel Galán
& Luis R. Izquierdo
In this website you will find all the information about our work trying
to replicate the simulation results reported by Axelrod
(1986) in an influential paper on
the evolution of social norms. Basically our study shows that Axelrod’s results are not as reliable as one would desire.
We can obtain the opposite results by running the model for longer, by slightly
modifying some of the parameters, or by changing some arbitrary assumptions in
the model. Of course, we can only say that almost 20 years after Axelrod published his paper: the computational power
required to undertake our study was just not available in 1986. The real interest of this re-implementation
exercise is that it has allowed us to draw some best-practice guidelines that
you may find useful when developing and analysing your agent-based models. In
particular, we illustrate the importance of running stochastic simulations
several times for many periods, of exploring the parameter space adequately, of
complementing simulation with analytical work, and of being aware of the scope
of our simulation models.
Use the menu on the left to download RAEAN (Re-implementation of Axelrod's "Evolutionary
Approach to Norms"). RAEAN is our agent-based model designed to replicate
and extend Prof. Axelrod’s model. Also, you will find
a user guide, an API (Application Programming Interface), an applet, and a link
to our paper, where we present our work in detail.
We hope that you will find this piece of work useful!
Reference:
Axelrod,
R.M., 1986. "An evolutionary approach to norms", American Political Science Review 80, nº4, December 1986:
1095-1111. Reprinted in Axelrod, R.
M., 1997. The
Complexity of Cooperation. Agent-Based Models of Competition and Collaboration.