When companies, or even countries, are under crippling financial pressure, getting short-term cash is all that matters. Such desperate behaviour is now observable at the Department of Finance, which has decided to persevere with the Air Passenger Departure (APD) tax despite the huge damage its doing to tourism, airlines and most of the largest airports.

The €10 tax on departures from the main airports is apparently bringing in revenues of about €10m a month, hardly transformative from an exchequer point of view. Of course, the revenue is welcome when you have a gap between revenue and expenditure of over €20bn, but has anyone in Merrion Street actually analysed all the plane journeys never taken, the holidays to Ireland never booked and the meals in restaurants never eaten by tourists because of this nasty little tax?

Last week, aviation watcher Joe Gill outlined his views on why the Department of Finance introduced the charge: "Someone replaced their brain with an abacus to invent this moronic tax (aping the UK) for an island economy dependent on tourism. It requires an adult to stop it".

An even more trenchant critic of the measure, and the leader of the 'axe-the-tax' campaign, is Ryanair. But its position is not without contradictions. Despite an APD tax in both Ireland and Britain – two very large markets for the carrier – passengers numbers are still growing by a healthy 11%.

The other problem for the airlines and the airports is that both have been happy to add on ancillaries to their own charging structures to shore up their revenues in economic downswings.

Nevertheless, a full investigation of the tax, one that goes beneath its bare revenue-raising elements, will probably discover that it's totally regressive and in net terms actually reduces exchequer revenues. Still, this logic may not impress itself on desperate men in desperate times.