“We have shown two important and related sets of facts. In most US industries, market shares have become more concentrated and more persistent. Industry leaders are less likely to be challenged and replaced than they were twenty years ago. At the same time, their profit margins have increased.”

“We have shown two important and related sets of facts. In most US industries, market shares have become more concentrated and more persistent. Industry leaders are less likely to be challenged and replaced than they were twenty years ago. At the same time, their profit margins have increased.”

— Thomas Philippon