For public investment, this is because spending £1 in London might generate £1.50 of economic improvement, but a similar project in Birmingham or Manchester might generate only £1.05 of improvement.
Are you comparing similar areas of London and other cities? If you don't visit anywhere outside central London, it's only fair to compare that with the centre of other cities.
Are you comparing similar areas of London and other cities? If you don't visit anywhere outside central London, it's only fair to compare that with the centre of other cities.