本文精选了经济学国际顶刊《The Review of Economic Studies》近期发表的论文，提供经济学研究领域最新的学术动态。

A Theory of Falling Growth and Rising Rents

原刊和作者：

The Review of Economic Studies Volume 90 Issue 6

Philippe Aghion （INSEAD）

Antonin Bergeaud （HEC Paris）

Timo Boppart （Stockholm University）

Peter J Klenow （Stanford University）

Huiyu Li （Federal Reserve Bank of San Francisco）

Abstract

Growth has fallen in the U.S. amid a rise in firm concentration. Market share has shifted to low labour share firms, while within-firm labour shares have actually risen. We propose a theory linking these trends in which the driving force is falling overhead costs of spanning multiple products or a rising efficiency advantage of large firms. In response, the most efficient firms (with higher markups) spread into new product lines, thereby increasing concentration and generating a temporary burst of growth. Eventually, due to greater competition from efficient firms, within-firm markups and incentives to innovate fall. Thus our simple model can generate qualitative patterns in line with the observed trends.

Link: https://doi.org/10.1093/restud/rdad056

The Lost Capital Asset Pricing Model

原刊和作者：

The Review of Economic Studies Volume 90 Issue 6

Daniel Andrei （Mungo Wilson）

Julien Cujean （University of Berne）

Mungo Wilson （Oxford University）

Abstract

We provide a novel explanation for the empirical failure of the capital asset pricing model (CAPM) despite its widespread practical use. In a rational-expectations economy in which information is dispersed, variation in expected returns over time and across investors creates an informational gap between investors and the empiricist. The CAPM holds for investors, but the securities market line appears flat to the empiricist. Variation in expected returns across investors accounts for the larger part of this distortion, which is empirically substantial; it offers a new interpretation of why “betting against beta” (BAB) works: BAB really bets on true beta. The empiricist retrieves a stronger CAPM on days when public information reduces disagreement among investors.

Link: https://doi.org/10.1093/restud/rdad056

Inference for Linear Conditional Moment Inequalities

原刊和作者：

The Review of Economic Studies Volume 90 Issue 6

Isaiah Andrews （Harvard University）

Jonathan Roth （Brown University）

Ariel Pakes （Harvard University）

Abstract

We show that moment inequalities in a wide variety of economic applications have a particular linear conditional structure. We use this structure to construct uniformly valid confidence sets that remain computationally tractable even in settings with nuisance parameters. We first introduce least-favorable critical values which deliver non-conservative tests if all moments are binding. Next, we introduce a novel conditional inference approach which ensures a strong form of insensitivity to slack moments. Our recommended approach is a hybrid technique which combines desirable aspects of the least favorable and conditional methods. The hybrid approach performs well in simulations calibrated to Wollmann (2018, American Economic Review, 108, 1364–1406), with favorable power and computational time comparisons relative to existing alternatives.

Link: https://doi.org/10.1093/restud/rdad056

Stalled Racial Progress and Japanese Trade in the 1970s and 1980s

原刊和作者：

The Review of Economic Studies Volume 90 Issue 6

Mary Kate Batistich （University of Notre Dame）

Timothy N Bond （Purdue University）

Abstract

We assess the impact of a rapid rise in Japanese import competition on the growth in racial earnings and employment gaps during the 1970s and 80s. Using commuting zone level variation in exposure, we find Japanese competition led to a decrease in manufacturing employment and labour force participation for blacks. This was driven by a shift in demand for skill in manufacturing. The difference in effects between the 10th percentile most and least exposed commuting zone was equivalent to 36–46% of the relative rise in black non-labour force participation, and 78–96% of the relative decline in black median male earnings.

Link: https://doi.org/10.1093/restud/rdad056

Bond Premium Cyclicality and Liquidity Traps

The Review of Economic Studies Volume 90 Issue 6

Nicolas Caramp （University of California）

Sanjay R Singh （University of California）

Abstract

Safe asset shortages can expose an economy to liquidity traps. The nature of these traps is determined by the cyclicality of the bond premium. A counter-cyclical bond premium opens the possibility of expectations-driven liquidity traps in which small issuances of government debt crowd out private debt and reduce output. In contrast, when the bond premium is pro-cyclical and the economy is in a liquidity trap, government debt is expansionary. In the data, we find evidence of a counter-cyclical bond premium. Large interventions can prevent the emergence of self-fulfilling traps, but they require sufficient fiscal capacity. In a quantitative model calibrated to the Great Recession, a promise to increase the government debt-to-GDP ratio by 20 percentage points precludes the possibility of self-fulfilling traps.

Link: https://doi.org/10.1093/restud/rdad056