I think what the article is trying to say is not that the free market has an unchanging interest rate, but rather that it is determined by market forces. Anyon

I think what the article is trying to say is not that the free market has an unchanging interest rate, but rather that it is determined by market forces. Anyone that wants to try to change the interest rate has to take risk to do so. The Fed, though, can change the interest rate in a risk-free fashion. So organizations that depend on the interest rate always have to hedge against potential changes in the interest rate not driven by market forces. I think the biggest issue that this article is chasing is that the interest rates so given are preferential by nature -- only certain eligible banks can claim the interest rate, and they are not being permitted to pass that on to their customers in an unadulterated form, so the market has to find ways to flow around this, to allow things like betting on derivatives related to a bank's performance in order to try to gain exposure to the underlying Fed-offered interest rate.