The value of a commodity is determined by the socially necessary labor time to produce it. The more socially necessary labor time it takes to produce a commodity, the greater its value. Therefore, time is money.

However, the socially necessary labor time for producing a certain commodity is not fixed, but changes with the change of labor productivity in various departments. Under the condition of constant social labor time, a single commodity producer has improved labor productivity and the total value created has been improved. So "efficiency is life".