"Why is inflation persistently high in some periods and low in others? The reason may be absence of commitment in monetary policy. In a standard model, absence of commitment leads to multiple equilibria, or expectation traps, even without trigger strategies. In these traps, expectations of high...

Galí (2014) showed that a monetary policy rule that raises interest rates in response to bubbles can paradoxically lead to larger bubbles. This comment shows that a central bank that wants to dampen bubbles can always do so by raising interest rates aggressively enough. This result is different...