Barriers to entry

What protects a profitable firm from the rivals its profits attract? Barriers to entry, the obstacles that keep newcomers out and let advantages last.

Barriers to entry are the obstacles that make it difficult for new firms to enter a market and compete with established ones. They are central to understanding why some firms earn lasting profits while others see theirs competed away, because without barriers, profits attract entrants who erode them.

Why barriers determine profitability

In a market with no barriers to entry, any profit above the normal level attracts new firms, whose entry increases supply, drives down prices, and competes the excess profit away. Lasting profitability therefore depends on barriers that keep potential entrants out. This is why barriers to entry are so central to strategy and competition policy alike: they are what allow market power and above-normal profits to persist rather than being eroded. The height of the barriers around a market largely determines how profitable, and how contestable, it is.

The kinds of barrier

Barriers take many forms. Some are structural: economies of scale that mean an entrant must come in large or face higher costs, large capital requirements, control of an essential resource or technology, and network effects that favour the incumbent. Some are strategic: established brands and customer loyalty, switching costs that lock customers in, and the threat of aggressive retaliation against entrants. Some are legal: patents, licences, and regulations that restrict who may compete. Often several combine to wall off a market.

Barriers as strategy and as harm

Barriers to entry are viewed differently depending on the vantage point. For an incumbent firm, building and defending entry barriers is sound strategy, the way to protect profits and sustain advantage, and much of competitive strategy is about raising the barriers around one's position. For competition policy, high barriers are a concern, because they entrench market power and shield incumbents from the competition that disciplines prices and spurs innovation. The same barrier that a strategist prizes is one a regulator may view with suspicion.

Barriers to entry are the hinge on which market power and lasting profitability turn. They explain why some advantages endure while others evaporate, why some markets stay concentrated and profitable while others are competed flat, and why so much of both business strategy and competition policy is, at bottom, about the obstacles that keep new competitors out.