We have all heard of the tendency of the rate of profit to fall.

But before explaining a fact by theory, we must first prove this fact by statistics. To prove that “something” down, we must first describe what is it, its measure, and its unit.

Profit is some value. Its measure is therefore the amount of labor. And its unit is hour, day, week, month, year of socially necessary labor.

But the socially necessary labor is abstract labor, not measurable concrete labor. How to establish a strict correspondence between the abstract labor and the concrete labor?

I suggest you find the solution by yourself and in 24h I will give you the answer.

To guide you, here are some clues:

According to Marx, what exactly is the “socially necessary labor”? The solution is entirely in the Section 1 of the Chapter 1 of the Capital (vol. 1): The Two Factors of a Commodity: Use-Value and Value [5].

According to this definition, you can find a special case where a determinate duration of concrete labor exactly contains the same amount of labor than the same duration of abstract labor. You will also find the solution in the section 1 named above.

After having found this correspondence, we will be able to estimate what is the global profit rate and see how it evolves over time. We can also anticipate how it will evolve over time.

**Send m****e**** your responses by PM**, at the right top of the web page (Write new message [6]).