Some Reflections on the Interactions between the Bank of England's Forecasts and the MPC's Policy Decisions

Abstract

This paper makes three main points. First, whereas the Monetary Policy Committee's forecasts of inflation and output growth in the UK are comparatively accurate, they cannot forecast deviations around trend, except at short horizons. Second, this is primarily because they adjust policy, the short-term interest rate, to drive inflation/output back to trend at their forecast horizon. This is not apparent when using a Taylor-rule using ex post forecasts, since these are published after taking account of policy changes. I use a rule of thumb to re-engineer estimates of the ex ante forecasts, upon which the policy decision was based. Also, because of the lengthy lags in the transmission mechanism, Central Bank decision-makers relate their interest decisions, not to current variables, but to forecast values for future inflation and output, with a forward-looking interest rate reaction function of the form: $$i_{t} = a b_{1} E_{t} {+AFw-left( {+AFw-pi _{{t j}} - +AFw-pi *} +AFw-right)} b_{2} E_{t} {+AFw-left( {y_{{t j}} } +AFw-right)}$$