On his blog, Stephen Williamson discusses the Fed’s plan to maintain a much larger balance sheet in the future than before the crisis. He is not convinced that this plan is a good one.
But what’s the harm in a large Fed balance sheet? The larger the balance sheet, the lower is the quantity of Treasury securities in financial markets, and the higher is reserves. Treasuries are highly liquid, widely-traded securities that play a key role in overnight repo markets. Reserves are highly liquid – for the institutions that hold them – but they are held only by a subset of financial institutions. Thus, a large Fed balance sheet could harm the operation of financial markets. … it would be reflected in a scarcity of collateral in overnight financial markets – in market interest rates. Before early 2018, T-bill rates and repo rates tended to be lower than the fed funds rate, and the fed funds rate was lower than IOER. Now, all those rates are about the same. The Fed thinks the difference is more Treasury debt, but I think the end of the Fed’s reinvestment program mattered, in that it increased the stock of on-the-run Treasuries. Whichever it was, apparently the quantity of Treasuries outstanding matters for the smooth – indeed, efficient – operation of financial markets, and the Fed should not mess with that. My prediction would be that, if we get to the end of the year and the Fed is again buying Treasuries, that we’ll see repo rates and T-bill rates dropping below IOER. Watch for that.