Macroeconomics 1st Edition by Dean Karlan,Jonathan Morduch

Exercise 14

Whenever AD or AS shifts, putting the economy out of long-run equilibrium, AS has a natural tendency to shift in such a way as to bring the economy back into long-run equilibrium. If the economy always eventually comes back to long-run equilibrium, why would the government ever try to implement policies to bring the economy into equilibrium through government means?