文档介绍：Classical thermodynamics and economic general equilibrium theory
Eric Smith ∗, Duncan K. Foley †
(November 19, 2002)
Careful examination of the axioms, and interpretation conventions, of utility theory and ther-
modynamics reveals that the two domains are more similar mathematically than their divergent
approaches to problem solving would suggest. Their differences inhere primarily in the economic
assignment of importance to initial endowments, versus the physical choice to emphasize reversible
transformations. Using an analysis based on reversible transformations in economics, it is shown
that utility theory can be represented as a theory of additive price potentials, and non-decrease of an
additive entropy in closed systems. The standard money-metric utility is identified as a Gibbs poten-
tial for demands, and a new contour money-metric utility is introduced as the conjugate Helmholtz
potential for prices. Examples show how the central problem-solving tools of thermodynamics apply
in detail to conventional utility models, with emphasis on the concepts of reversible transformation,
the equation of state, and engines.
JEL categories: B0, D5, D6 Keywords: Thermodynamics and economics, utility, economic potentials, economic
entropy
∗Santa Fe Institute, 1399 Hyde Park Road, Santa Fe, NM 87501
†Department of Economics, Graduate Faculty, New School University, 65 Fifth Avenue, New York, NY 10003
1
I. INTRODUCTION
A. Different conventions; same abstractions?
Both neoclassical economics and classical thermodynamics seek to describe natural systems in terms of solutions to
constrained optimization problems. The observables that link their respective theories to measurement have an obvious
formal correspondence: supply and demand vectors in economics resemble the generalized energies and volumes of
physical systems; prices resemble generalized temperatures and pressures. Yet there are striking differences in the
ways these analogue pa