Your numbers aren't quite right. Birmingham lost 15% of its population between 1950 and 2000, Philadelphia lost 26% in that period. It's not hard to find other

Your numbers aren't quite right. Birmingham lost 15% of its population between 1950 and 2000, Philadelphia lost 26% in that period. It's not hard to find other similar industrial UK cities which were harder hit. Newcastle lost 24% of its population over the same period, Liverpool lost a staggering 43%. Even in London, within the inner city where industry resided the working poor lived, e.g. Hackney, lost 22% of its population. None of these areas have recovered their former populations. This refutes your claim about London growing - it's the suburbs within greater London that have grown and it is there where the population shifted. Just as in the US, cities have shrunk while their surrounding metro areas have grown. Having seen the desolation of the boarded up industrial sites of Philadelia and of the UK, I can say that they look pretty similar (that is to say shocking - though far more so in my youth). The general pattern of cities in the UK's industrial north is exactly the same as that seen in the US - a small, regenerated downtown, surrounded by small, low-quality dwellings occupied by low income families, surrounded by increasingly nice suburbs where everybody else lives. I'm not sure why anybody thinks this problem is unique to the US.