Sometimes they are. Most times they aren't. Short and simple.
Designer clothing could be an investment as it shapes the way you look. Which in turn determines how other people look at you or "respect" you.
Designer clothing is an investment because the quality is higher than that high street crap. It looks better (hopefully). And lasts muuuuuuch longer!
But, from a pure financial point, designer clothes aren't really investments. Especially not for a student or young professional spending from their income or pocket money.
Here's the thing, for it to be an investment, your designer clothes, shoes or bags need to bring you some sort of return--today or in twenty years.
So the Balmain shoes you buy today should be able to bring some money in everyday. Whether you wear them or leave them on your shoe rack. As well as have the potential to be resold, hopefully for a profit. But how often does that happen?
Also, let's not lie to ourselves. Most of us buy designer outfits to look cool, feel rich, impress others and.... "Investing in designer clothing" doesn't always come with an attached expectation to make money back. Which is sort of fine, because you dont necessarily expect to make money back from Zara or H&M clothing (if that's your taste) when you buy them.
Designer clothes could be you succumbing to consumerism. Or simply being stupid with your money as you don't realise the opportunity lost by doing so.
This is something to think about. I guess that's why it's a good thing that all investments aren't made with financial intelligence. Or maybe not?
Morgan Housel’s “the Psychology of Money” talks about a very powerful idea in relation to this: real wealth is unseen. Is their wealth hidden behind unseen tastes in clothing?