摘要：Banks are special in that their liabilities are widely
accepted as a means of payment, thereby often needed by real
sectors to obtain resources. This paper studies this interaction
between the banking sector and real sectors on competitive
markets and the policy response of the central bank to market
inefficiency, which is determined by the aggregate wealth of
banks. In the circumstance of a credit crunch, the central bank
improves efficiency by allowing banks to borrow its fiat money
at zero interest up to a limit. This policy bears the flavor of
quantitative easing policies (QE). It produces real effects in
the absence of surprises and nominal rigidity. The mechanism
in which it works depends on a difference in nature between
bank-created money and fiat money. Furthermore, this policy,
while expanding the money supply, induces deflation under the
positive productivity shock. Lastly, this paper explains when
interest rate policy and capital adequacy regulation are among
the optimal policies within a unified model.
