Large pyramidal family controlled business groups are the predominant form of business organization outside America, Britain, Germany, and Japan. Large pyramidal groups comprising dozens, even hundreds, or listed and unlisted firms place the governance of large swathes of many countries' big...

Recent research documents that ownership concentration is higher in countries with weak investor protection. However, drawing on panel data on corporate ownership in 34 countries between 1995 and 2006, we show this pattern does not hold for newly public firms, which tend to have concentrated...

Motivated by public policy debates about bank consolidation and conflicting theoretical predictions about the relationship between the market structure of the banking industry and bank fragility, this paper studies the impact of bank concentration, bank regulations, and national institutions on...

Does the mere presence of big banks affect macroeconomic outcomes? In this paper, we develop a theory of granularity (Gabaix, 2011) for the banking sector, introducing Bertrand competition and heterogeneous banks charging variable markups. Using this framework, we show conditions under which...

The substantial fluctuations in oil prices in the wake of the COVID-19 pandemic and the Russian invasion of Ukraine have highlighted the importance of tail events in the global market for crude oil which call for careful risk assessment. In this paper we focus on forecasting tail risks in the...

Since the inception of Medicare Part D in 2006, mergers and acquisitions (M&A) and regulatory changes have led to increased concentration and reduced plan variety in the standalone prescription drug plan (PDP) portion of the market. We examine how this industry consolidation affects Medicare...

We study the evolution of profits, investment and market shares in US industries over the past 40 years. During the 1990's, and at low levels of initial concentration, we find evidence of efficient concentration driven by tougher price competition, intangible investment, and increasing...