But again, the question is not about the existence of SCP and that it preceded (or more strongly, transitioned into) capitalism. Everyone knows that commodity production existed prior to capitalism, and that it did not encompass the whole of the economy then as it does in capitalism. SCP is not just some "category", but a historical fact. The question is whether the law of value applied in SCP. Although Rubin says that he will not consider that question:Rubin wrote:
Here we will not be concerned with the historical controversy over whether commodities were exchanged in proportion to the labor expended on their production before the emergence of capitalism.
That's the thing: When Rubin is talking about "simple commodity production", he is talking about a theoretical abstraction that is used to explain how capitalism works, he is not talking abut a historical period preceding capitalism. So the question to what degree actual pre-capitalist production fit into the model of "simple commodity production" isn't really relevant to the subject he is studying.
In A contribution Marx gave a brief reference to the "general law which regulates corn prices" in the ancient world:
The sudden and forcible transfer of hoarded money from one country to another is a specific feature of the ancient world; but the temporary lowering of the production costs of precious metals achieved in a particular country by the simple method of plunder does not affect the inherent laws of monetary circulation, any more than, for instance, the distribution of Egyptian and Sicilian corn free of charge in Rome affects the general law which regulates corn prices.
-
I assume he means ancient Rome.