The Elusive Costs of Inflation: Price Dispersion during the U.S. Great Inflation*
Quarterly Journal of Economics · 2018 · Emi Nakamura、Jón Steinsson、Patrick Sun、Daniel Villar
中文摘要
一个关键的政策问题是：中央银行应将通胀率目标设定为多高？这在很大程度上取决于通胀的成本。一个重要的担忧是，高通胀会导致无效率的价格离散。常用的新凯恩斯主义模型意味着，这种通胀成本非常大。在这些模型中，稳态通胀率从0%上升至10%所带来的福利损失，比产出的经济周期波动所造成的福利损失高出一个数量级。我们利用一套关于美国20世纪70年代末和80年代初大通胀时期价格行为的新数据集，对这一预测进行实证评估。如果价格离散随通胀上升而迅速加剧，我们应当观察到价格变动的绝对幅度随通胀上升而增大：在更高的通胀率下，价格偏离其最优水平更远，因此价格变动的幅度应当更大。我们未发现大通胀时期价格变动的绝对幅度上升的证据。这提示，新凯恩斯主义关于通胀福利成本的标准分析是错误的，其关于最优通胀率的理论含义需要重新评估。我们还发现，非促销价格在过去40年中并未变得更加灵活。
Abstract
A key policy question is: how high an inflation rate should central banks target? This depends crucially on the costs of inflation. An important concern is that high inflation will lead to inefficient price dispersion. Workhorse New Keynesian models imply that this cost of inflation is very large. An increase in steady-state inflation from 0% to 10% yields a welfare loss that is an order of magnitude greater than the welfare loss from business cycle fluctuations in output in these models. We assess this prediction empirically using a new data set on price behavior during the Great Inflation of the late 1970s and early 1980s in the United States. If price dispersion increases rapidly with inflation, we should see the absolute size of price changes increasing with inflation: price changes should become larger as prices drift further from their optimal level at higher inflation rates. We find no evidence that the absolute size of price changes rose during the Great Inflation. This suggests that the standard New Keynesian analysis of the welfare costs of inflation is wrong and its implications for the optimal inflation rate need to be reassessed. We also find that (nonsale) prices have not become more flexible over the past 40 years.