Rising rates, however, have not always been a heartening prospect for banks. It used to be, as in most industries, that when the price of their main input—money—went up, profits fell. A paper* published in 2014 by three economists at the Federal Reserve Board explains why. Short-term rates are usually lower than long-term ones. Since most deposits are short-term, but many of the loans banks make, in the form of things like mortgages, are long-term, the gap between short and long rates helps to pad the NIM. But as long-term rates rise, so does the discount rate that must be applied to future earnings, depressing the value of long-term assets more than short-term liabilities. Moreover, higher rates crimp economic growth, curbing demand for loans and raising the number of defaults.
Why have banks’ share prices risen, in that case? In theory, banks have learned to insulate themselves from the adverse effects of rising rates. Relatively few banks still follow the textbook model, simply taking in deposits and dispensing long-term credit, notes Frederick Cannon of KBW, an investment bank. Instead, they often sell off the loans they originate or use derivatives to hedge against rate hikes. At the same time, many are raising more funds through certificates of deposits and or other fixed-rate, longer-term instruments.
Nonetheless, notes Mr Cannon, similar optimism about the impact of the first rate rise after a long period of rock-bottom rates proved misplaced at Japanese banks in 2006. Loan demand remained sluggish, margins narrow and share prices listless. Even if banks manage to avoid the write-downs on assets that have come with rate rises in the past, they still face another problem: the possibility that the price of attracting deposits rises more quickly than the interest they can charge on loans.
Deposits are normally assumed to be “sticky”, meaning that customers do not bother to move their money around very often in search of higher rates. Changing banks is simply too much hassle. That effect may be diminishing, however, as technology makes it easier to find and exploit better deals. What is more, other banks are not the only entities competing for savings. Money-market mutual funds, which have ceased to provide much competition to banks as the securities they must invest in provide little return, might become fiercer rivals if rates rose.
In short, bankers betting on higher interest rates may be disappointed. When banks borrow short and lend long, they are vulnerable to the revaluations rate rises bring. It would be natural to respond by providing ever less long-term credit. But in doing so, they may also deprive themselves of long-term rewards