The standard illustration is the QWERTY keyboard, arranged in the 1870s for the mechanics of typebars and kept ever since, long after the constraint disappeared. Whether a better layout exists is argued about; what is not argued about is that the reason for keeping it is that everybody already knows it.

An outcome persists because of the commitments built on top of it, not because it was chosen on merit.

The mechanism

A small early advantage attracts investment. That investment raises switching costs for everyone involved. Higher switching costs attract more investment, because the thing now looks permanent. Within a few cycles the choice is effectively irreversible, and the original advantage may have been tiny or accidental.

Notice the order. It is not that the best option won and then accumulated support. It is that something won early enough and then accumulated the support that made it the best available option.

Where it operates in a business

Pricing model. Hourly, retainer or fixed-fee — whichever you started with shapes which clients you attracted, what your contracts say, how your reporting works, and how your team thinks about their day. Changing it in year six means changing all of those.

Tech stack. Chosen in a week, lived with for a decade, and it decides who you can hire.

Client mix. The first few clients determine your references, which determine the next clients, which determine your positioning. Very few firms choose their market; most discover the one their first three clients put them in.

Your own skills. What you learned first shapes what you got asked to do, which shaped what you learned next. That is career capital compounding, and it is path dependence seen from the inside.

What to do with it

Take early decisions more seriously than their size suggests. A choice made casually in month two is doing more work than a carefully analyzed choice made in year four, because everything after it inherits it.

Prefer reversible options early. Not the best option — the one that keeps the most doors open, which is what optionality buys and why it is worth paying for.

Re-examine inherited constraints explicitly. Ask what you would choose today with no history. The gap between that and the current arrangement is the cost of the path, and naming it is the only way to decide whether the cost is worth paying.

Distrust "this is how it is done." In a path-dependent market that sentence is a statement about history and is routinely mistaken for one about quality.