演講者簡介 : Prof. Tomoyuki Nakajima (中?智之) 為Ph.D. Economics，University of Chicago。現為Associate Professor，Institute of Economic Research, Kyoto University。其主要研究領域為Macroeconomics。論文發表於國際著名期刊，包括Review of Economic Studies, Journal of Economic Theory, Economic Theory, European Economic Review, Journal of Development Economics, etc.
演講摘要 : Can changes in expectations be viewed as a cause of the business cycle? The standard real business cycle model suggests that they cannot. In such a model, a change in expectations will move consumption and investment (and labor) in opposite directions, which is not what we observe over the business cycle. In this paper, we augment the standard model with a certain type of borrowing constraint. Specifically, we assume that firms are subject to collateral constraint in financing their input costs. We show that in such a model changes in expectations can generate business cycles, where all macroeconomic variables move in the same directions. Intuition is simple: optimistic expectations will raise the price of the collateral asset and relaxes the collateral constraint of the firms, which, in turn, increase the wage rate and thus the labor input. It follows that consumption, labor, investment, and output all rise in response to an optimistic change in expectations.
