disequilibrium

Disequilibrium refers to a state in which a system is not in thermodynamic, economic, or dynamic balance, and driving potentials such as concentrations, currents, prices, or other forces continue to change or produce net flows. It contrasts with equilibrium, where these effects vanish and macroscopic properties remain effectively constant over time.

In thermodynamics and chemistry, disequilibrium means that chemical reactions or transport processes are ongoing and the system’s components are not described by a uniform chemical potential. Many natural and biological systems maintain disequilibria because they store or release energy. Examples include ion gradients across membranes, redox couples, and metabolic fluxes that power life processes. While near-equilibrium conditions allow straightforward application of Le Chatelier’s principle, far-from-equilibrium states involve continuous energy throughput and complex dynamics.

In economics and other social sciences, disequilibrium describes markets where supply does not equal demand, leaving prices, quantities, or other variables in motion until forces push the system toward balance. Causes include price rigidities, information asymmetries, external shocks, or policy interventions. Disequilibrium can also arise in labor, capital, or goods markets during transitions or crises.

Dynamics and measurement: Disequilibrium can be static or dynamic. External forcing or internal constraints prevent the system from reaching rest, and relaxation toward equilibrium occurs at rates set by interactions and transport processes. The degree of disequilibrium can be quantified by deviations in chemical potentials, concentrations, or excess demand, and by the presence of sustained flows or gradients.

See also: equilibrium, non-equilibrium thermodynamics, homeostasis, Le Chatelier’s principle, market clearing.