In the science of physics, we know that ice freezes at 32 degrees. We can predict with immense accuracy exactly how far a rocket ship will travel filled with 500 gallons of fuel. There is preciseness because there are constants, which do not change and upon which equations can be constructed.. There are no such constants in the field of economics since the science of economics deals with human action, which can change at any time. If potato prices remain the same for 10 weeks, it does not mean they will be the same the following day. I defy anyone in this room to provide me with a constant in the field of economics that has the same unchanging constancy that exists in the fields of physics or chemistry. And yet, in paper after paper here at the Federal Reserve, I see equations built as though constants do exist. It is as if one were to assume a constant relationship existed between interest rates here and in Russia and throughout the world, and create equations based on this belief and then attempt to trade based on these equations. That was tried and the result was the blow up of the fund Long Term Capital Management, a blow up that resulted in high level meetings in this very building. It is as if traders assumed a given default rate was constant for subprime mortgage paper and traded on that belief. Only to see it blow up in their faces, as it did, again, with intense meetings being held in this very building. Yet, the equations, assuming constants, continue to be published in papers throughout the Fed system. I scratch my head.