demand and supply decisions simultaneously. Then how can this simultaneity be rational ized practice? One first finds that this simultaneity is indeed rationalized in the t tonnement process Agents, in the t tonnement process, are supposed to put forward their demand and supply decisions simultaneously at quoted prices. These demand and supply decisions are not subject to actual exchanges. Actual exchanges will not take place until the equilibrium has been reached Yet outside the t tonnement, this simultaneity can hardly be rationalized First, a decision without exchange is economically meaningless. Second, agents cannot have two types of exchanges, demand and supply, to take place at the same time. Naturally there is a problem which one is the first? One should note that this issue, which one is the first? has long been suppressed in economic literature. Weintraub(1977, pp. 4)once regarded"the simultaneity"as one of the anomalies of neoclassical system, but did not provide a solution. Benassy(1982)was even entangled. In chapter 4, he distinguishes the time ordering of an agent's different decisions Through this manner, he appropriately illustrates the " spill-over effect"caused by an"initial disturbance"transmitted from market to market. Yet in chapter 7, he gives up this distinction and works again on the simultaneous nature of adjustment process. Though he believes that"in reality agents visit marke ts sequentially, "(pp 63)working on simultaneous nature, in his mind, is absolutely standard in all multi-market equilibrium model and it will simplify the exposition, as we shall not have to formalize the ordering of the markets. "(pp. 63) But this"standard"is mislead ing. In practice, agents cannot visit all markets simultaneously Second, that ordering, as we shall see later, can be formalized. Third, that ordering is crucial to economic analysis: when the ordering is appropriately formalized, the equilibrium state, at which the actual quantities are transacted, is completely different from the one achieved by the trad itional equilibrium analysis, essentially, the analysis based on simultaneity4 demand and supply decisions simultaneously. Then how can this simultaneity be rationalized in practice? One first finds that this simultaneity is indeed rationalized in the t_tonnement process. Agents, in the t_tonnement process, are supposed to put forward their demand and supply decisions simultaneously at quoted prices. These demand and supply decisions are not subject to actual exchanges. Actual exchanges will not take place until the equilibrium has been reached. Yet outside the t_tonnement, this simultaneity can hardly be rationalized. First, a decision without exchange is economically meaningless. Second, agents cannot have two types of exchanges, demand and supply, to take place at the same time. Naturally there is a problem "which one is the first?". One should note that this issue, "which one is the first?", has long been suppressed in economic literature. Weintraub (1977, pp. 4) once regarded "the simultaneity" as one of the anomalies of neoclassical system, but did not provide a solution. Benassy (1982) was even entangled. In chapter 4, he distinguishes the time ordering of an agent's different decisions. Through this manner, he appropriately illustrates the "spill-over effect" caused by an "initial disturbance" transmitted from market to market. Yet in chapter 7, he gives up this distinction and works again on the simultaneous nature of adjustment process. Though he believes that "in reality agents visit markets sequentially,"(pp. 63) working on simultaneous nature, in his mind, is "absolutely standard in all multi-market equilibrium model and it will simplify the exposition, as we shall not have to formalize the ordering of the markets."(pp. 63) But this "standard" is misleading. In practice, agents cannot visit all markets simultaneously. Second, that ordering, as we shall see later, can be formalized. Third, that ordering is crucial to economic analysis: when the ordering is appropriately formalized, the equilibrium state, at which the actual quantities are transacted, is completely different from the one achieved by the traditional equilibrium analysis, essentially, the analysis based on simultaneity