The crucial difference from the general equilibrium theory lies in the stress on the market
process as contrasted to the state of market equilibrium. It is perhaps best illustrated
by the relation of the respective theories to prices under which the trade is allowed to be
carried out. While in real economies as well as in the income theory of money framework
trade goes on irrespective of whether the actual prices are equilibrium ones or not,
the general equilibrium theory explicitly forbids this to happen. It was already Walras
(1977 [1871], pp. 40-1) who pointed out that not a single transaction may pass in the
general equilibrium model under non-equilibrium prices. If it did, the whole system of
equilibrium conditions would get upset. That is why he introduced his concept of
“Walrasian auctioneer” and the so called “tâtonnement process”. Its sole purpose was to
find the equilibrium prices first, and to allow all trade to happen only after. The original
as well as the present versions of general equilibrium models are in the end about an
exchange of bundles of goods under a fixed set of all prices.