I would argue that yes bubbles do exist, but that it is very hard to identify bubbles with certainty and almost impossible to reach consensus about whether a particular asset price boom period should be considered a bubble or not. Economists have often been described as “the great prophets of the past”.
And fourth, even if a tendency towards greater stability were durably to take hold in the nonmonetary field (something we do not know), that would not release monetary policy, for its part, from its obligation to keep the monetary side in order. For overly expansionary monetary growth always poses a threat – both to price stability and to the stability of the financial markets.