Macroeconomics has become interested inmarket power.A series of studies over the past few years has documented a set of possibly interrelated, broad-based, and decades-long trends: increased market concentration, higher profit rates, higher measured price-cost markups, decreased investment rates, reduced firm entry and factor market dynamism, and a fall in labor’s share of income. If one wanted to offer a single, plausibleon-its-face explanation for these trends, it would be reasonable to argue that there has been a broad increase in market power among producers in the economy. This interest in market power extends beyond just productmarkets. Characterizing the role ofmonopsony, especially in the labor market, is an active research area as well. However, there are potential alternative explanations for many of the trends described earlier. These include a growing role for intangible capital in production, increases in product market substitutability due to the expansion of trade or decreases in consumer search costs, and other shifts in production technologies that have increased returns to scale. Moreover, a set of studies has offered evidence for these mechanisms—in case studies, certainly, but in more broadly scoped empirical settings as well. I view the goal of the Covarrubias, Gutiérrez, and Philippon paper as trying to bring together andmake sense of those many data patterns and conflicting stories. On the theory side, the paper shows how a commonly used class of models captures many of the proposed explanations for the aforementioned data trends, and it uses such models to point to possible empirical tests to discriminate among these explanations. On the empirical side, it applies these tests in an attempt to identify the most likely explanation for the data trends. (Though as I note later, the collage of

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宏观经济学对市场力量产生了兴趣。过去几年的一系列研究记录了一系列可能相互关联、基础广泛且持续数十年的趋势：市场集中度提高、利润率提高、可衡量的价格成本加价率降低、投资率、企业进入和要素市场活力减少以及劳动收入份额下降。如果人们想对这些趋势提供一个单一的、表面上似是而非的解释，那么有理由认为经济中生产者的市场力量已经广泛增强。这种对市场力量的兴趣不仅限于产品市场。描述垄断的作用，尤其是在劳动力市场中的作用，也是一个活跃的研究领域。然而，对于前面描述的许多趋势，有潜在的替代解释。其中包括无形资本在生产中的作用越来越大，由于贸易扩张或消费者搜索成本下降而导致产品市场替代性增加，以及生产技术的其他转变增加了规模回报。此外，一系列研究为这些机制提供了证据——当然是在案例研究中，但也在更广泛的经验环境中。我认为 Covarrubias、Gutiérrez 和 Philippon 论文的目标是试图将这些许多数据模式和相互矛盾的故事结合起来并加以理解。在理论方面，该论文展示了一类常用模型如何捕获对上述数据趋势的许多建议解释，并使用此类模型指出可能的实证检验以区分这些解释。在经验方面，它应用这些测试试图确定数据趋势的最可能解释。（虽然我后来注意到，拼贴