Concentration has increased over the last 30 years or so in a variety of industries. This development has raised concern about weakened competition and resulting harm to consumers. Calls for tougher antitrust enforcement have become louder. There is also concern that rising concentration may be...

Concentration and price-cost margins have increased since the 1980s in many industries. These developments have raised concern about weakened competition and resulting harm to consumers and the need for tougher antitrust enforcement. In 1973 Harold Demsetz cautioned against inferring weakened...