Pareto cautiously asserted that the wealth and income distributions which
bear his name are universal, basing his argument on observations of this distribution
in many different types of economies. In this paper, we present an agent based model
(and a scalable approximation of it) in a closely related spirit. The central feature of
this model is that wealth enables an individual to secure more wealth. Specifically, the
important and novel feature of this model is its ability to simultaneously produce both
the Pareto distribution observed in empirical data for the top 10% of the population
and the exponential distribution observed for the lower 90%. We show that the model
produces these distributions of wealth when initialized with an equitable distribution.

• An agent-based model of the observed distribution of wealth in the United States