But they could not obtain the expected results. The solution of the stagnancy problem can be obtained only when their economic system changes into a free economic system, which can assure the effect of profit and the effect of efficacy most effectively. Introduce briefly the theory of surplus value. The capitalist economy is the economy which seeks profit. This profit cannot be produced in the circulation process, but only in the production process and only by means of labor power.
Surplus labor means unpaid labor which is performed during surplus working hours.
Surplus hours are the hours by which total working hours exceed necessary working hours. Necessary working hours are the working hours for which wages are paid. Since labor power is a kind of commodity, it needs certain quantity of labor to be produced. This labor quantity is equal to the amount of labor needed to produce the necessities of life required to sustain life such as food, clothing and medicine. Therefore, the price of daily necessities of life equals the price of labor power, that is, wages.