In a liquidity trap, which we are in, it is simply economics. The interest rate will not durably go up, there are too much savings, too little demand and therefore too little investment. So unless you have a model to show how interest rates would go up, I would say the one doing the assuming is you.

It may of course be a matter of fact that high civil servants make this same assumption, but I don't understand why you would lend any credence to the claim on that basis. After all, they have been wrong about most everything lately. Why would they be right on this score?

The Hun is always either at your throat or at your feet. Winston Churchill