[boombust]

I wouldn't say it is a problem on its own. Look at Japan. Almost everything being in Tokyo is not a problem because their transport system is excellent.

The UK's problem is that transport policy is abysmally backward and our property market is outrageously disparate and historically overvalued (as land was how a person demonstrated their wealth which has perpetuated unlike other countries where industry holdings are valued much more, e.g. America and Germany). Take your example of Paris, much smaller but equally historic, yet prices there are much lower than in London. London is a more global city than Paris but not so much as to explain the discrepancy in property market values.