So the British are increasing the international departure tax, and stating that it is an “externality tax”. What spectacularly wrong-headed logic.
The externality they are talking about is “carbon emissions” – now as long as they tax the fuel that airlines use the externality is accounted for, as the carbon emissions stem from fuel use. Adding a tax on top of an efficient externality tax is not efficient.
The real reason the British government is doing this is straight out protectionism – they believe that the impact on “outflows” from Britain will exceed the impact on tourist “inflows”, a factor that would improve net exports and help to “protect” the retail industry in Britain. Beyond this, the increase in tax is also a simple tax grab – one that taxes tourist industries the rest of the world over.