You might not think it, but planes overbooking passenger seats benefits everyone if it's handled correctly

Selling more seats than there are on a plane might look like the unacceptable face of airline capitalism; many travellers are enraged by the possibility that they could buy a ticket for a flight but then be turned away at the gate because the departure is “oversold”.

Yet overbooking, when practised properly, is an important asset in aviation. Selling all the seats on a plane and then some more benefits airlines, passengers and the environment.

Carriers do not squander empty seats that they could have sold; the last figures supplied to me by easyJet show an average of 5 per cent of passengers are “no-shows”.

You may not be convinced by the airlines’ assertion that overbooking keeps fares down rather than enriching shareholders. But allowing passengers to book seats on flights that are already theoretically full is a genuine advantage, because it helps people who need to travel urgently at short notice. And flying planes full reduces the damage per passenger on the environment.

Any airline that chooses to sell 5 or 10 per cent more tickets than there are fitted to the plane should be allowed to do so. But now and again the airline guesses wrong, and everyone shows up.

When handled properly, this scenario pays off handsomely for travellers. The correct way to tackle it, legally as well as morally, is for the airline to offer sufficient compensation to entice enough passengers to travel on a later flight. Time and again, though, airlines handle overbooking abysmally – denying boarding randomly, and in the case of United Airlines, dragging a hapless passenger, Dr David Dao, from a plane at Chicago.

The very same week in 2017, easyJet turned away a couple at Luton airport as they tried to board their holiday plane to Sicily and neglected to mention their entitlement to compensation and alternative flights.

Now the government in Canada is getting serious, with new rules taking effect this summer that require a payment of $2,400 (over £1,400) to any passenger who is denied boarding and arrives over nine hours late. That is the sort of figure that should persuade airlines to do the right thing – and help preserve overbooking as the virtue that it is.

Yours,

Simon Calder

Travel correspondent