Fairly / The Queue and Other Everyday Systems

Why first come first served keeps winning

The queue survives because it is cheap, visible and hard to game.

A queue at a counter is a fairness rule with no information requirement beyond arrival order, and that is its whole genius. It does not ask who needs the service most, who has travelled furthest, or who has been waiting patiently all week for this errand. It asks one question with an answer everybody present can see. Because the answer is public, disputes about it are rare and short. Because it costs nothing to administer, it can be used anywhere, by anyone, without a supervisor. Very few allocation rules manage all of that at once.

The queue also has the unusual property of charging a price that is not money. Standing in line costs time, and time is distributed more evenly across people than most other things are. That gives the queue an appearance of even handedness that survives scrutiny reasonably well. It is not perfect: the person who can arrive at six in the morning has an advantage over the person who cannot, and that advantage is invisible from inside the line. But compared with the alternatives available at a suburban counter, it is remarkably difficult to improve on.

What the queue cannot do is respond to urgency. The person with a small errand and the person with a serious problem occupy the same position, determined entirely by who walked through the door first. Most places handle this by carving out an exception, an express lane or a separate desk, and the exceptions are where the arguments live. Once you allow one departure from arrival order you have conceded that arrival order is not the only thing that matters, and every subsequent case has to be argued on grounds the queue itself does not supply.