When it comes to quantitative easing (QE), where you stand definitely depends on where you sit. That is among the conclusions of the important new report of the Economic Affairs Committee of the UK House of Lords.

The report provides an excellent survey of how it is that central banks now use their balance sheets. Its key conclusions are the following. First, central bankers should clearly communicate the rationale for their balance sheet actions, stating what they are doing and why. Second, policymakers should provide more detail on their estimates (and uncertainties) of the effectiveness of their various actions, especially QE. Third, they should be aware that the relationship between central bank balance sheet policy and government debt management policy poses a risk to independence. Finally, and most importantly, central bankers need an exit plan for how they will return to a long-run sustainable level for their balance sheet.

We discussed several of these points in prior posts. On communication, we argued that central bankers should be clear about their reaction function for both interest rate and balance sheet policies (see here). On the justification for policymakers’ actions, we emphasized the need for clear, simple explanations tied to policymakers’ objectives, distinguishing carefully between the intended purposes (such as monetary policy, lender/market maker of last resort, or emergency government finance; see here). And, on the relationship between QE and fiscal finance, we noted how the ballooning of the U.S. Treasury’s balance at the Fed in the early stages of the pandemic looked like monetary finance, putting independence at risk (see here).

In this post, we turn to the challenge that Lord King highlights in the opening quote: the need to ensure that central banks do not see bond purchases as a cure-all for every ill that befalls the economy and the financial system, causing their balance sheets repeatedly to ratchet upward….