Marginal cost发表评论(0)编辑词条

In economics and finance, marginal cost is the change in total cost that arises when the quantity produced changes by one unit. That is, it is the cost of producing one more unit of a good.[1] Mathematically, the marginal cost (MC) function is expressed as the first derivative of the total cost (TC) function with respect to quantity (Q). Note that the marginal cost may change with volume, and so at each level of production, the marginal cost is the cost of the next unit produced.

In general terms, marginal cost at each level of production includes any additional costs required to produce the next unit. If producing additional vehicles requires, for example, building a new factory, the marginal cost of those extra vehicles includes the cost of the new factory. In practice, the analysis is segregated into short and long-run cases, and over the longest run, all costs are marginal. At each level of production and time period being considered, marginal costs include all costs which vary with the level of production, and other costs are considered fixed costs.

A number of other factors can affect marginal cost and its applicability to real world problems. Some of these may be considered market failures. These may include information asymmetries, the presence of negative or positive externalities, transaction costs, price discrimination and others.

从理论上讲，边际成本（marginal cost）是指产量（业务量）向无限小变化时，成本的变动数额。当然，这是从纯经济学角度来讲的，事实上，产量不可能向无限小变化，至少应为1个单位的产量。因此，边际成本也就是产量每增加或减少一个单位所引起的成本变动数额。

由此看来，边际成本和变动成本是有区别的，变动成本反映的是增加单位产量所追加成本的平均变动，而边际成本是反映每增加一个单位产量所追加的成本的实际数额。所以，只有在相关范围内，增加一个单位产量的单位变动成本才能和边际成本相一致。
如果把不同产量作为不同方案来理解的话，边际成本实际就是不同方案形成的差量成本。