If changes in the balance sheet are now acting as a substitute for changes in the federal funds rate, then one might expect balance sheet decisions to also be governed to a large extent by the evolution of the FOMC’s economic forecasts. The earlier purchase program, in contrast, did not demonstrate much responsiveness to changes in economic or financial conditions. Indeed, the execution of the program largely involved confirming the expectations that were put in place by the two early announcements. Third, how persistent should movements in the balance sheet be? An important feature of traditional monetary policy is that movements in the federal funds rate are not quickly reversed, which makes them more influential on broader financial conditions. A change that was expected to be transitory would instead move conditions very little. For similar reasons, one could argue that movements in the balance sheet should have some persistence in order to be more effective. Fourth, to what extent should the FOMC communicate about the likely path of the balance sheet? The FOMC often communicates about the path of the federal funds rate or provides other forward-looking information that allows market participants to anticipate that path. This anticipation of policy actions is beneficial, as it brings forward their effects and thus helps to stabilize the economy. For the same reason, providing information about the likely course of the balance sheet could be desirable.
In particular, by purchasing longer-term securities, the Federal Reserve removes duration risk from the market, which should help to reduce the term premium that investors demand for holding longer-term securities. That effect should in turn boost other asset prices, as those investors displaced by the Fed’s purchases would likely seek to hold alternative types of securities. Some research studies have estimated that the effects of the earlier expansion of our securities holdings by just over $ trillion lowered longer-term Treasury yields by about 50 basis points through this portfolio balance channel. 3 These effects on Treasury yields appear to have been transmitted into lower rates on private credit instruments and higher asset prices more broadly. 1  Reflecting the long-standing practice of the Desk, principal payments on our holdings of Treasury securities were already being fully reinvested at Treasury auctions. 2  The Fed’s asset purchases initially had an additional and important effect on mortgage rates by improving the functioning of the MBS market. As I have noted in earlier speeches, the use of the central bank’s balance sheet can be particularly effective when focused on markets in which liquidity and market functioning have become impaired. The focus here is whether, in addition to those effects, the size and composition of the Fed’s balance sheet have a lasting impact on financial conditions in well-functioning and relatively liquid markets.