De Loecker, Eeckhout, and Unger document that since 1980 aggregate markups in the U.S. economy have significantly increased from 21% above cost to 61% now. In light of this evidence, this paper revisits optimal fiscal and monetary policy recommendations of standard New Keynesian models and shows that under empirically relevant calibrations of market power they radically change: the optimal inflation rate becomes significantly positive and its optimal volatility sharply rises. Moreover, inflation behaves like a random walk in response to unexpected fiscal shocks. Thus, price stability ceases to be the optimal policy outcome.

中文翻译：

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市场力量的崛起和拉姆齐最优政策的影响

De Loecker，Eeckhout和Unger的文件显示，自1980年以来，美国经济中的总加价幅度已从高于成本的21％大幅增加到现在的61％。根据这一证据，本文重新审视了标准新凯恩斯模型的最佳财政和货币政策建议，并表明，在经验相关的市场力量校准下，它们会发生根本性的变化：最佳通货膨胀率显着为正，其最佳波动率急剧上升。此外，通货膨胀的行为就像是对意外的财政冲击的随意走动。因此，价格稳定不再是最佳的政策结果。