Business Cycles in International Historical Perspective
回顾了经济周期理论的核心问题，即哪些冲击扰动经济以及何种结构传播冲击，并比较了货币冲击与非中性、实际冲击与均衡等不同理论视角。
Business cycle models seek to answer the question of why economies go through cycles of recession and recovery, or boom and bust. Any theory of the business cycle makes two sorts of claims: what shocks are most important in disturbing the economy and what economic structure is necessary for propagating these shocks. For example, one common explanation of business cycles begins with monetary shocks, and then seeks to explain why monetary shocks are not purely neutral, as neoclassical theory would have it, and instead have real effects, at least in the short term. Early models in this vein were often implicitly or explicitly based on the proposition that markets do not clear continuously. Early equilibrium "real business cycle" theories instead emphasized the importance of real shocks, especially to technology, which may cause socially efficient fluctuations even when markets are always in equilibrium. More recent models have attempted to marry the equilibrium approach to macroeconomics with the substantive Keynesian ideas that money is not neutral and that economic fluctuations are costly.