The writer is an external member of the Bank of England’s Monetary Policy Committee
Generations of economists — myself included — were taught to think about changes in economic activity primarily in terms of demand. But supply can prove every bit as consequential for output and inflation, as we recently experienced in the face of a pandemic and a war in Europe. We’ve learnt a number of lessons about how negative supply shocks propagate through the economy and how central banks might respond to them.
The conventional wisdom is that monetary policymakers should look through adverse supply shocks. First, they are often transitory and there is a lag before monetary policy has an impact on the economy, so any response would probably come to bear too late. Second, adverse supply shocks tend to push output down and inflation up. Monetary policymakers generally respond more cautiously to these shocks as they weigh the benefits of stabilising prices with the costs of weakening output. Third, if inflation expectations are well anchored, second-round effects should be avoided. Finally, interest rates are a demand-management tool, with little direct impact on supply.