He is clearly in favor of the free market.
Monetarists are also in favor of a free market. Milton Friedman was one.
As an Austrian, one of our most important beliefs is that interest rates should be determined by the market, not central banks. They are the chief enabler of big government by virtue of being a buyer of last resort of government debt instruments. In addition, all sorts of malinvestments result when central bankers try to fix the time price of money. Interest is the most important price in any economy, and government or their proxies should never fix interest rates.
Clark is no big opponent of government meddling. I would classify him as a Keynesian Light in terms of economic proclivity.