Analyzing Indeterminacies in a Real Business Cycle Model with Money
探讨在偏好、禀赋和技术本身不足以确定唯一均衡的模型中，货币传导机制如何解释货币、利率、价格和产出的时间序列特征，并借助多重均衡和动物精神来解释经济周期。
My purpose in wnting the paper Money in a Real Business Cycle Model was to explore the idea that the transmission may be explained in an equilibrium model in which preferences, endowments, and technology are, on their own, insufficient to pin down a unique equilibnum. By the monetary transmission mechanism I mean the time series properties of money, interest rates, pnces, and output in data from Europe and the United States. According to a common interpretation of these data, a change in the money supply has real effects on output in the short run but it is neutral in the long run. I had also hoped that an explanation of the transmission that relies on indeterminacy might rest solely on the idea that money is useful as a medium of exchange. I am indebted to Kirill Sossounov for pointing out a sign error in the computations in my 1997 article and for rescuing the message of the paper with minimal alterations to the basic framework. We have several examples of calibrated models of real economies in which the theoretical structure permits the existence of multiple stationary equilibria and I have argued elsewhere (Farmer 1993) that models of this class can be completed by specifying a rule by which agents form beliefs. These models suggest the possibility that animal spirits or ''self-fulEllling may have an independent role in propagating business cycles and that this possibility is fully consistent with the hypothesis of rational expectations and market clearing. We also have examples of models in which multiple equilibria may play a role in the transmission of shocks.l But to date, none of these models has been calibrated with the same degree of attention to the explanation of data as has become typical in the real business cycle literature. My 1997 paper, with Sossounov's amendments, goes some way toward filling this gap. From an argument onginally advanced by Negishi in 1960, it is known, if one imposes standard assumptions of convexity of preferences and technology, that infinite horizon economies with a finite number of agents typically contain a finite odd number of equilibna. From this fact, it follows that steady-state equilibna are locally determinate and that multiplicities that are exploited in models of self-fulfilling prophecies cannot occur.