As suggested in the rhetorical expression “the worst crisis in 100 years,” the usefulness of theories and experiences formulated in the past has been considerably constrained, and as the borders among countries have disappeared due to globalization, the lines between economic policies have been blurred and policies have become interdependent.
Since the government’s policy measures have shown their limits, the economy has begun to rely on the role of the central bank, and this has been well demonstrated in the cases of advanced economies where various unconventional instruments have been employed due to the constraints imposed by the ZLB.