  The emergence of labor division in multi-agent system is analyzed by the
method of statistical physics. Considering a system consists of N homogeneous
agents. Their behaviors are determined by the returns from their production.
Using the Metropolis method in statistical physics, which in this model can
been regarded as a kind of uncertainty in decision making, we constructed a
Master equation model to describe the evolution of the agents distribution.
When we introduce the mechanism of learning by doing to describe the effect of
technical progress and a formula for the competitive cooperation, the model
gives us the following interesting results: (1) As the results of long term
evolution, the system can reach a steady state. (2) When the parameters exceed
a critical point, the labor division emerges as the result of phase transition.
(3) Although the technical progress decides whether or not phase transition
occurs, the critical point is strongly effected by the competitive cooperation.
  From the above physical model and the corresponding results, we can get a
more deeply understanding about the labor division.
