FRBSF Economic Letter: Monetary Policy, Money, and Inflation (2012-21, 6/30/2012)
A great letter describing how our current environment has forced us to rethink textbook monetary policy.
Before interest on reserves, the opportunity cost for holding noninterest-bearing bank reserves was the nominal short-term interest rate, such as the federal funds rate. Demand for reserves is downward sloping. That is, when the federal funds rate is low, the quantity of reserves banks want to hold increases. Conventional monetary policy works by adjusting the amount of reserves so that the federal funds rate equals a target level at which supply and demand for reserves are in equilibrium. It is implemented by trading noninterest-bearing reserves for interest-bearing securities, typically short-term Treasury bills.
Normally, banks have a strong incentive to put reserves to work by lending them out. If a bank were suddenly to find itself with a million dollars in excess reserves in its account, it would quickly try to find a creditworthy borrower and earn a return. If the banking system as a whole found itself with excess reserves, then the system would increase the availability of credit in the economy, drive private-sector borrowing rates lower, and spur economic activity. Precisely this reasoning lies behind the classical monetary theories of multiple deposit creation and the money multiplier, which hold that an increase in the monetary base should lead to a proportional rise in the money stock.
Moreover, if the economy were operating at its potential, then if the banking system held excess reserves, too much “money” would chase too few goods, leading to higher inflation. Friedman’s maxim would be confirmed. Here’s the conundrum then: How could the Fed have tripled the monetary base since 2008 without the money stock ballooning, triggering big jumps in spending and inflation? What’s wrong with our tried-and-true theory?
A critical explanation is that banks would rather hold reserves safely at the Fed instead of lending them out in a struggling economy loaded with risk. The opportunity cost of holding reserves is low, while the risks in lending or investing in other assets seem high. Thus, at near-zero rates, demand for reserves can be extremely elastic. The same logic holds for households and businesses. Given the weak economy and heightened uncertainty, they are hoarding cash instead of spending it. In a nutshell, the money multiplier has broken down (see a discussion in Williams 2011a).
The change is that the Fed now pays interest on reserves. The opportunity cost of holding reserves is now the difference between the federal funds rate and the interest rate on reserves. The Fed will likely raise the interest rate on reserves as it raises the target federal funds rate (see Board of Governors 2011). Therefore, for banks, reserves at the Fed are close substitutes for Treasury bills in terms of return and safety. A Fed exchange of bank reserves that pay interest for a T-bill that carries a very similar interest rate has virtually no effect on the economy. Instead, what matters for the economy is the level of interest rates, which are affected by monetary policy.This means that the historical relationships between the amount of reserves, the money supply, and the economy are unlikely to hold in the future. If banks are happy to hold excess reserves as an interest-bearing asset, then the marginal money multiplier on those reserves can be close to zero. As a result, in a world where the Fed pays interest on bank reserves, traditional theories that tell of a mechanical link between reserves, money supply, and, ultimately, inflation are no longer valid. In particular, the world changes if the Fed is willing to pay a high enough interest rate on reserves. In that case, the quantity of reserves held by U.S. banks could be extremely large and have only small effects on, say, the money stock, bank lending, or inflation.