The model of perfect competition is one of the most famous, most important, and most misunderstood concepts in economics. Rather than aiming to be a full-blown model of real-world competitive markets, the perfect competition model isolates the decentralized coordination mechanism inherent in all...

An increasing body of empirical evidence is documenting trends toward rising concentration, profits, and markups in many industries around the world since the 1980s. Two major criticisms of these studies is that concentration and market shares are poorly measured at the national industry level...