It is only when the shock turns out to be persistent that patterns will change significantly. In this sense, it is a stabilizing force, giving other sources of demand that can be quickly influenced by policy actions, time to respond to and help mitigate the impact of the shock.
Second, the capacity to launch a strong policy response was in place when the crisis hit. On the monetary front, the tight, anti-inflationary stance that preceded the crisis had taken policy rates and the cash reserve ratio to relatively high levels.