  Many models of market dynamics make use of the idea of wealth exchanges among
economic agents. A simple analogy compares the wealth in a society with the
energy in a physical system, and the trade between agents to the energy
exchange between molecules during collisions. However, while in physical
systems the equipartition of energy is valid, in most exchange models for
economic markets the system converges to a very unequal "condensed" state,
where one or a few agents concentrate all the wealth of the society and the
wide majority of agents shares zero or a very tiny fraction of the wealth. Here
we present an exchange model where the goal is not only to avoid condensation
but also to reduce the inequality; to carry out this objective the choice of
interacting agents is not at random, but follows an extremal dynamics regulated
by the wealth of the agent. The wealth of the agent with the minimum capital is
changed at random and the difference between the ancient and the new wealth of
this poorest agent is taken from other agents, so establishing a regulatory
tool for wealth redistribution. We compare different redistribution processes
and conclude that a drastic reduction of the inequality can be obtained with
very simple regulations.
