Is deflation good or bad? Just mind the inflation gap

We explain why the macroeconomic effects of shocks to inflation of the same size, but opposite sign, are not necessarily symmetric. All in all, the costs of deflation and disinflation tend to exceed those of inflation due to the presence of constraints in the economy, namely the zero lower bound on nominal interest rates, downward nominal wage rigidity and borrowing limits. When these constraints are binding, they can prevent monetary policy from closing the inflation gap, labor market from clearing and agents from deleveraging. The impact of a disinflationary shock on the tightness of these constraints depends on the cyclical and structural conditions of the economy. We argue that it would be a mistake to assume that perverse effects can arise only with actual deflation and thus that the classification of deflationary episodes into good (supply-driven) and bad ones (demand-driven) is not only incorrect, but also misleading in terms of policy implications. Empirical evidence for the euro area suggests that the three constraints have become increasingly tight recently.