Price Rigidity, Economic Fluctuations, and Economic Growth

这是对一个对宏观经济学、金融经济学、经济增长和劳动经济学做出重要贡献的项目的基于成就的更新。这笔赠款允许研究者继续研究两大类：(1)价格刚性和经济波动理论和(2)经济增长理论。宏观经济学的一个基本问题是：是什么决定了通货膨胀率？大多数宏观经济学家一致认为，从长远来看，通胀的主要决定因素是货币供应量的增长。然而，通胀的短期行为更具争议性。当然，货币政策和其他决定总需求的因素发挥着重要作用。然而，自20世纪70年代以来，许多经济学家也强调了“供应”或“价格”冲击的作用。这个项目的贡献来自于发展了关于相对价格变化如何影响通货膨胀率的严格理论，并对战后美国通胀变化中由价格冲击解释的部分进行了进一步的实证研究。特别强调了欧佩克的能源冲击：石油密集型商品价格的大幅上涨引起了价格冲击，总通货膨胀上升。这项研究显然与理解碳税和其他全球环境变化政策的经济影响或全球环境灾难造成的未来价格冲击的经济影响有关。该项目的另一部分继续研究标准增长理论与生活水平趋同证据之间的差距。研究人员研究了各种各样的数据集，得出的结论是，经济趋于趋同--也就是说，贫穷经济体的增长速度往往快于富裕经济体。然而，标准的经济增长模型很难解释这一事实。该项目开发了一个经济增长模型，解释了人均产出的逐步趋同，同时允许各个经济体的实际利率在任何时候都是相等的。该模型的关键在于，借款可以为物质资本的积累提供资金，但不能为人力资本的积累提供资金。更广泛地说，这个项目研究了穷国和富国的事实对生产函数形式的限制，如劳动力、人力资本和实物资本之间的互补性。

This is an accomplishment based renewal of a project that has made important contributions to macroeconomics, financial economics, economic growth and labor economics. This grant permits the investigator to continue research in two broad categories: (1) theories of price rigidity and economic fluctuations and (2) theories of economic growth. One of the fundamental questions of macroeconomics is: What determines the rate of inflation? Most macroeconomists agree that in the long run, the primary determinant of inflation is growth in the money supply. The short-run behavior of inflation, however, is more controversial. Certainly monetary policy and other determinants of aggregate demand have important roles. Yet since the 1970s, many economists have also emphasized the role of "supply" or "price" shocks. The contribution of this project comes from developing a rigorous theory on the way shifts in relative prices can affect the rate of inflation and conducting further empirical research on the fraction of the variation in inflation in the postwar United States that is explained by price shocks. Special emphasis is placed on the OPEC energy shocks: large increases in the prices of oil-intensive goods generated price shocks and aggregate inflation rose. This research is clearly relevant to understanding the economic implications of carbon taxes and other global environmental change policies or economic implications of future price shocks caused by global environmental catastrophes. The other part of the project continues research on the gap between standard growth theory and the evidence on convergence in standard of living. Researchers examining a wide variety of datasets have concluded that economies tend to converge--that is, poor economies tend to grow faster than rich economies. Yet standard models of economic growth cannot easily explain this fact. The project develops a model of economic growth that explains gradual convergence in output per person while allowing the real interest rate to be equal across economies at all times. The key to the model is that borrowing is possible to finance accumulation of physical capital but not accumulation of human capital. More generally, this project studies the restrictions that facts about poor and rich countries place on the form of the production function, such as complementarity among labor, human capital, and physical capital.