Two days to go. Presents? Panic!

Why do you always leave your Christmas shopping to the last minute? Is it fear of death? Low self-esteem? Acute procrastination disorder? That's the theory according to one academic. Whatever the reason, Jim White will be present-hunting in the convenience store again this year

Joseph R Ferrari, of the Centre for Life Studies, Cazenovia College, New York, has the perfect excuse for not doing his Christmas shopping. "Sorry, honey," he can say. "I was too busy, stuck down the Mall researching why people leave their Christmas shopping to the last minute."

In the land where the works of Madonna have inspired a university degree course, and an intimate knowledge of knitting patterns can land you a doctorate, Dr Ferrari's research has the sniff of real scientific rigour about it. "Christmas and procrastination," is the title of his paper, "Explaining the lack of diligence at a real-world task deadline."

Dr Ferrari examined 240 mall shoppers, measuring "procrastination scores (on arousal and avoidance measures), the closeness of the measurement to Christmas, and shoppers' rationales for why they were shopping at that particular time." He reckoned procrastinators were "motivated by arousal from working against a deadline and attributed their lack of diligence to job-related attributes (eg work, business commitments) that compelled them to begin shopping at the last possible opportunity." Or they were motivated by a need to "avoid situations involving threats to self-esteem, attributing their postponed shopping to personal attributes (eg lack of energy, indecisiveness, perceived task aversiveness) reflecting their belief in their own inabilities."

So there we have it. The reason I was standing, at 11 o'clock on the evening of one Christmas Eve in a motorway service station, deciding whether my mother would prefer the shameful box of Milk Tray in my right hand or the wilting pot plant in my left was because I was consumed by self- loathing. Nothing to do with the 48 hour bender from which I had just emerged, nothing to do with the car not starting, nothing to do with working for a man who combined the less generous instincts of Scrooge and Gradgrind in one miserly, misanthropic package of a kind which regarded leaving work before five on Christmas Eve as a firing offence.

However, Dr Ferrari does have a point. Since Christmas now begins in the shops the moment the fireworks are put away, there are 50 days in which to organise a buy-round. There must be a reason why so many of us refrain from doing anything at all about it until the last plausible nano- second. Fear of death is my explanation: a postponement of that which we know is inevitable in the misplaced conviction that the act of putting it off will somehow prevent it happening. But, like the need to throw up after the office party, in the end there is nothing you can do to stop it happening, so you comfort yourself by waiting until the last possible moment.

The lot of the inveterate last-minuter is helped considerably if you have money. Then you can hit the shops like a credit-card fuelled locust, scooping the gaudy off the shelves with a recklessness that will be regretted only when the bill arrives at the month end. The shopping areas of airports can be very useful in this regard: who, you wonder, as you pass them by for 363 days of the year, would ever want the shamelessly over-priced, offensively pointless items that abound there? The answer is: on Christmas Eve when your have so far bought precisely nothing, your family and friends. And best of all, the staff will gift wrap them. Last year a colleague bought, in the ten-minute window he had at Heathrow before the last Yuletide flight to Belfast was called, a Santa's sack of gifts: saucy underwear from the Knickerbox franchise, Body Shop smellies, a boy's football shirt, and that stalwart of the procrastinator: booze, lots of it. All was popped on to the credit card, all was scrumptiously wrapped and all was weepingly received by grateful relatives, astonished by the thought and attention lavished upon them.

Penury, though, compounds the adrenalin-rush panic of the last-minute. As a student I can remember standing bemused in 24-hour newsagents debating whether the pounds 2.35 in my pocket would best be served buying the girlfriend's parents the Christmas and New Year copy of The Radio Times, or a jumbo pack of Juicy Fruit; always bearing in mind it had to stretch to procure presents for mum, dad and two siblings as well. Fortunate, then, I'd had the foresight to bag the girlfriend a Salon-sized bottle of Wash 'n' Go from the discount chemists already.

There are people who maintain that waiting until the last minute opens up a huge vista of bargain opportunities: that, after five on Christmas Eve, turkey prices tumble to a penny a pound; that Christmas trees are given away; that street traders pay you to take boxes of Santa hats off their hands. But to discover such giveaways requires the kind of organisation and foresight not familiar to the procrastinator; my experience of the last-minute universally involves paying the recommended retail price and above.

And this year, thanks to a change in the law, the disorganised have been given an extension to their deferral. For the first time that Christmas Eve has fallen on a Sunday, we have a whole extra shopping day in which to delay. And if, at 5pm, standing in your local Tesco Metro fumbling with a pot-plant, a Dogs 96 calendar and a festive pine car-freshener you are approached by an academic with a clip-board asking you what you are doing, just ask him a question in response: if he's so clever, when does he do his Christmas shopping?