  We build a statistical ensemble representation of two economic models
describing respectively, in simplified terms, a payment system and a credit
market. To this purpose we adopt the Boltzmann-Gibbs distribution where the
role of the Hamiltonian is taken by the total money supply (i.e. including
money created from debt) of a set of interacting economic agents. As a result,
we can read the main thermodynamic quantities in terms of monetary ones. In
particular, we define for the credit market model a work term which is related
to the impact of monetary policy on credit creation. Furthermore, with our
formalism we recover and extend some results concerning the temperature of an
economic system, previously presented in the literature by considering only the
monetary base as conserved quantity. Finally, we study the statistical ensemble
for the Pareto distribution.
