Credit, Money, and Aggregate Demand
修改了教科书中的IS-LM模型，使信贷和债券不完全替代，从而分析信贷供给和需求冲击对总需求的独立影响，并探讨货币与信贷作为政策指标的相对价值。
Standard models of aggregate demand treat money and credit asymmetrically; money is given a special status, while loans, bonds, and other debt instruments are lumped together in a "bond market" and suppressed by Walras' Law. This makes bank liabilities central to the monetary transmission mechanism, while giving no role to bank assets. We show how to modify a textbook IS-UI model so as to permit a more balanced treatment. As in Tobin (1969) and Brunner-Meltzer (1972), the key assumption is that loans and bonds are imperfect substitutes. In the modified model, credit supply and demand shocks have independent effects on aggregate demand; the nature of the monetary transmission mechanism is also somewhat different. The main policy implication is that the relative value of money and credit as policy indicators depends on the variances of shocks to money and credit demand. We present some evidence that money-demand shocks have become more important relative to credit-demand shocks during the 1980s.