What do you mean? It has been proven empirically, see work done by Paul Cockshott. Coming from pure reason, the theory is pretty sensible as well, and provides

What do you mean? It has been proven empirically, see work done by Paul Cockshott. Coming from pure reason, the theory is pretty sensible as well, and provides a good model to understand the origin of value in the economy. It is especially useful when trying to understand the effects of massive automation on society.