There’s no two ways about it: some men consistently wear trousers that are far too long for their legs. It’s a common phenomenon in men of a certain age: Messrs Donald Trump, Simon Cowell, Bernie Sanders and Jacob Rees-Mogg all look as though they put on their trousers in the morning and then had their bodies shrunk by a cruel wizard, the fabric spooling out around the bottom of their legs and onto the ground. Politicians seem especially prone to the problem but, as Mr Cowell demonstrates, it can affect men in other industries as well – even Jay-Z and Mr Shaquille O’Neal have struggled in this area. (Impressive, given that Mr O’Neal is over 7ft tall.) Seeing President Trump’s trousers lengthen almost by the week, we took it upon ourselves to investigate the phenomenon.

This particular style mistake is an unfortunate thing to see if you are a fan of clothes. It wastes and often ruins them, the folds of material creasing pointlessly or even dragging on the filthy floor. While trousers can certainly be too short and too tight on a man, the opposite problem makes it look as though the person in question is borrowing the clothes of a much bigger friend.

So why do we see so many men in the public eye wearing trousers that are simply too long for them? “Men of a certain age prefer that wider, parallel-leg look – not quite a bell-bottom – as opposed to the more contemporary look, which is a little bit slimmer, a little bit more fitted, a little bit more tapered,” says men’s tailoring brand Scabal. Wearing trousers like this can hide “a multitude of sins”. Scabal’s tailors advise on trouser length, no matter how powerful the customer is, but individuals will always have their own idiosyncratic preferences.

President Trump has X-shaped legs, or knock-knees, as they’re more commonly known, says Mr Maximilian Ciampi of 40 Savile Row: they go in at the knees and out at the feet, forming the shape of the letter “X”. Wearing wider, longer trousers can disguise the “X”, but if he had a tighter fit at the bottom of the leg, the shape of his legs would be more defined, something Mr Ciampi suggests he may be insecure about. Hackett co-founder Mr Jeremy Hackett agrees, wondering if long, wide trousers are the product of low self-esteem and act as an “unconscious cover-up”. Mr Ciampi further points out that some men wear longer trousers to disguise the heel that is making them taller.

One theory is that men believe that longer trousers themselves will lend an appearance of height. But it turns out, too-long trousers have the opposite effect, says a tailor from Gieves & Hawkes: “It just makes you look like a chicken nugget.” If they are too long, the trousers spill out to the side, creating more width and making the observer see the wearer as too small for the trousers. Another interesting theory, from an expert at Oliver Sweeney, is that men might revert to the style of clothing they wore during the era when they were most attractive, pointing out that Mr Cowell favours a distinctive look that was very popular during the 1980s, when flared trousers were more in vogue.

A man’s relationship with his tailor is extremely important. If a customer is going to buy dozens of suits from you, there might not be much incentive to tell them that, in your opinion, trousers should be worn higher up the leg: you may suddenly lose a great deal of custom.

So, what can be done about it? If you are worried about looking short and therefore shy away from short trousers, don’t, says Mr Ciampi. A man who is short and wears narrow, well-fitted trousers will be doing himself a favour, as they will make him look slimmer and taller. If you are extremely tall and slim, however, wearing trousers that are very narrow may make you look too thin; Mr Ciampi suggests a fuller-pleated trouser for this body shape. In addition to this, says Mr Tommy Raban from Scabal, turn-ups can make the bottom of your legs look a little wider.

So, if bunched-up trouser hems are a giveaway that the pair is too long, how long should a man wear his trousers? It depends on a person’s shape and taste, of course, but Mr Raban recommends that there should be a single break (the fold of the trouser fabric as it meets the top of your shoe) on your trousers. This means that “you can show off a nice pair of socks and shoes as well.” The hem should be sitting on the top of the heel of the shoe, says Mr Ciampi. The trend may currently be leaning toward narrow, shorter trousers, but Mr Ciampi recommends cuffs so that, when you walk, your trousers don’t look ridiculously short. As for around the waist, Mr Raban thinks that the trousers should be worn about an inch below the belly button.

In other words, listen to your tailor. They know what they’re talking about.