长期以来，我国的政治经济学教材的观点是：商品的价值量是由社会必要劳动时间决定的，社会必要劳动时间随着劳动生产率的变化而变化。一个牛产部门的劳动生产率越高，单位时间内生产的商品越多，则单位商品内包含的劳动时间越少，价值量也就越小。反过来，部门的劳动生产率越 For a long time, China’s political economy textbooks point of view is: the value of goods is determined by the socially necessary working time, social labor hours with changes in labor productivity changes. The higher the labor productivity of a cattle producing department, the more goods produced per unit of time, the less labor time contained in a unit of goods, the smaller the amount of value. In turn, the more labor productivity the department has