Entry Deterrence and Strategic Capacity Commitment

What this topic is

Entry deterrence is everything an incumbent does before a potential competitor decides, in order to make entering unprofitable. The main instrument is capacity: building more than current demand requires, so that if entry happens you can flood the market from an asset whose cost is already spent. That is not a bluff. Once the capacity exists your own marginal cost has fallen, so producing a lot really is your best move. And the entrant, running the same arithmetic, sees a market that will not have room for them at a price they can survive.

Why it matters

The value of a protected market is enormous relative to the value of a shared one, so the arithmetic on deterrence is rarely close. What is close, and usually gets skipped, is whether deterrence is achievable at all. Capacity has a hard ceiling on what it can threaten, because you will only ever produce what is optimal for you after entry, and a rival with a low enough entry cost cannot be kept out by any amount of steel. Knowing which case you are in is the difference between a defensible position and years of capital tied up in an asset earning nothing.

Who should learn it

Incumbents in capital-intensive regional markets, anyone approving a capacity expansion justified by competitive rather than demand reasons, and any potential entrant trying to read whether an incumbent is genuinely defended or merely large.

What you will understand

• Why sunk capacity changes an incumbent's post-entry behaviour and an announcement does not
• How to compute the minimum deterring capacity from your demand curve and the entrant's cost of entering
• The ceiling on what capacity can achieve, and how to recognise a market that cannot be defended this way
• The other deterrents (exclusive contracts, product proliferation, and reputation), and where each one binds

Prerequisites

• The Vickrey-Clarke-Groves Mechanism and Why Nobody Runs It
• The Principal-agent Problem and the Optimal Contract

Common misconception

"Enough capacity will keep anyone out." There is a hard limit, and it comes from the same logic that makes capacity work in the first place. Capacity is credible because you would actually use it. But you will only use as much as is optimal against the entrant's output, and beyond that point extra capacity sits idle after entry exactly as it did before. So there is a maximum amount of output an incumbent can credibly threaten, a corresponding floor under the entrant's post-entry profit, and if the entrant's cost of entering is below that floor, no capacity programme on earth deters them. At that point the capital is better spent competing.