Understanding the forces behind these phenomena or anomalies is important to thinking through what they mean for policy. When Alan Greenspan first used the term “conundrum” to describe the surprising behavior of forward interest rates, he was reacting to the decline in forward nominal rates over a period in which the Federal Open Market Committee was raising its federal funds target rate. This behavior of forward rates, the counterpart of which is the behavior of the bond yield curve, looked anomalous both in comparison to observations from past tightening cycles and with what seemed to be strong evidence about the fundamental soundness of the outlook for the real economy. The source of the relatively low level of nominal rates is still a matter of considerable debate. Part of the explanation lies in the decline in expectations of future inflation and uncertainty about future inflation. Part of the explanation may also lie in greater confidence that the secular decline in the variability of economic growth observed over the past two decades in the United States is likely to continue. However, even with the information provided by the development of the market for inflationindexed government securities, we have less ability than we would like to draw conclusions about what any nominal forward rate means for expectations about the level of future real rates, uncertainty about future real rates, and what those might imply about expectations about future economic activity. This uncertainty makes it harder to assess the appropriate path of monetary policy.
By contrast, the central bank essentially holds nothing but liquid assets – largely government securities (Chart 49). Shifting deposits away from commercial banks, and towards the central bank, would therefore make for a “narrower” banking system – a “narrow” bank being one whose assets are as liquid as its liabilities. In principle, it would also make for a safer one. Backed by liquid assets, rather than risky lending, deposits would become inherently more secure. They wouldn’t be vulnerable to “runs” and we would no longer need to insure them. 8  Nor is it a live issue for the Bank. As the Governor recently said to the House of Commons’ Treasury Committee, “May I…be absolutely clear: there are no plans to abolish cash at the Bank of England”. 9  The Bank of England’s balance sheet has obviously grown following QE. Those operations have been conducted via the Asset Purchase Facility (APF), which is not directly on the Bank’s balance sheet – strictly speaking, the blue bar in Chart 4 is not direct holdings of gilts but a loan from the Bank to the APF. But the APF itself holds only gilts and, even before QE, the vast majority of assets on the Bank’s balance sheet were government securities. BIS central bankers’ speeches  5  The case for narrow banks has a long and distinguished pedigree. The classical economists Adam Smith and David Ricardo favoured such a system.