Volker Nocke, Michael D. Whinston, 26 August 2020

Concentration measures such as the post-merger Herfindahl-Hirschman index as well as the merger-induced change in the index are usually key determinants in the review of horizontal mergers by competition agencies and courts. This column studies whether the magnitude of the efficiencies required for a merger not to hurt consumers may be related to the change and the level of the Herfindahl-Hirschman index. On the basis of theoretical analysis substantiated by empirical evidence, it finds that while the critical level of efficiencies depends on the change in the index, it is independent of level of the index. Hence current guidelines should be changed so as to emphasise the change more and the level less.

Federico Diez, Jiayue Fan, Carolina Villegas-Sanchez, 02 August 2019

Studies of the evolution of market power since 2000 have focused mostly on publicly traded US firms. This column introduces a new global study that incorporates private firms, and decomposes the aggregate effect into intensive and extensive margins. It shows the increase in markup is broad-based across countries and sectors, but is driven by a small number of firms. The markup increase is mainly explained by increases in the average markup of incumbents, and reallocation effects towards new firms that gain market share from incumbents. 

Ufuk Akcigit, Sina T. Ates, 04 July 2019

The US economy has witnessed a number of striking trends that indicate rising market concentration and a slowdown in business dynamism in recent decades. This column uses a micro-founded model of endogenous firm dynamics to show that a decline in the intensity of knowledge diffusion from frontier firms to laggard ones plays a key role in the observed shifts. It presents new evidence on higher concentration of patenting in the hands of firms with the largest stock that corroborates declining knowledge diffusion in the economy. 

Will Abel, Silvana Tenreyro, Gregory Thwaites, 23 January 2019

Concentrated labour markets, in which workers have few choices of potential employers, reduce the wages of workers when they are not covered by collective wage bargaining agreements. But these types of agreements have become much less common in the past 20 years. This column uses employee-level data to show that even though UK labour markets have not on average become much more concentrated, concentration – which varies a great deal across regions and industries – is having a bigger impact on wages than before.

José Azar, Ioana Marinescu, Marshall Steinbaum, Bledi Taska, 07 June 2018

The effect of increasing product market concentration on the labour market is sometimes overlooked because the labour market is often assumed to be entirely competitive. This column discusses the definition of labour markets and analyses the circumstances in which employers have monopsonist power to set wages, thus contributing to the growing debate over whether market concentration might be one cause of stagnant wages and other labour trends. 

Christos Genakos, Tommaso Valletti, Frank Verboven, 16 June 2017

Europe is experiencing a wave of mergers in the telecommunications industry. This column argues that an increase in market concentration in the mobile industry generates an important potential trade-off: while consolidation increases prices, investment per operator also goes up. Competition and regulatory authorities should be open to the potential trade-off between market power effects and efficiency gains from agreements between firms.

Thorvaldur Gylfason, Per Wijkman, 06 February 2017

There is a cross-country relationship between economic performance and both economic and political diversification. This column presents global evidence that between 1962 and 2012, both types of diversification were closely related to economic performance. This period included the spread of democracy, the global liberalisation of trade, and the termination of the Cold War. The recent retreat of democracy, the popular reaction to trade liberalisation in key countries, and a new cold war appear likely to reduce economic efficiency and growth. 


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