The problem is that the banks can borrow so cheaply that they actually don't want to pay their clients the interest rates on their accounts. As it expensive for

The problem is that the banks can borrow so cheaply that they actually don't want to pay their clients the interest rates on their accounts. As it expensive for the bank, and increases the bank's liabilities/risks (money in the books) hence they will lower the rates. Which then hopefully will lower the amounts on the books by people either moving it out of the bank or spend it. That's what I understood from the bankers when I was working at a bank :) They a had a simple formula representing but can't find my notes now. I am 'enjoying' interest rates on my bank accounts around the world between -0.5%-1.5%. I really should sort out the negative rent.