John states:

“[Roy] says that we can’t even talk about an optimum level of government expenditure for education — since such a level can only be determined by a competitive market process.”

No John, I am not saying that an optimum level can only be determined by a competitive market process. I am saying that the whole concept of an optimum allocation of resources with optimum levels of production is meaningless claptrap. It is meaningless both in and outside of a market setting. Once this is understood, the entire circularity “problem” goes away. I hate to say this, but read my book.