The impact of QE on the UK economy – some supportive monetarist arithmetic

This paper uses a simple money demand and supply framework to estimate the impact of quantitative easing (QE) on asset prices and nominal spending. We use standard money accounting to try to establish the impact of asset purchases on broad money holdings. We show that the initial impact of £200 billion of asset purchases on the money supply was partially offset by other ‘shocks’ to the money supply. Some of these offsets may have been the indirect result of QE. Our central case estimate is that QE boosted the broad money supply by £122 billion or 8%. We apply our estimates of the impact of QE on the money supply to a set of ‘monetarist’ econometric models that articulate the extent to which asset prices and spending need to adjust to make the demand for money consistent with the increased broad money supply associated with QE. Our preferred, central case estimate is that an 8% increase in money holdings may have pushed down on yields by an average of around 150 basis points in 2010 and increased asset values by approximately 20%. This in turn would have had a peak impact on output of 2% by the start of 2011, with an impact on inflation of 1 percentage point around a year later. These estimates are necessarily uncertain and we show the sensitivity of our results to different assumptions about the size of the shock to the money supply and the nature of the transmission mechanism.