Start with international arrivals. In absolute terms London and Tokyo led the field last year, with 20m visitors each, followed by Istanbul, with 17m. Global cities attract lots of visitors. Divide them by population, though, and Amsterdam, Paris and Milan claim the top three spots, with a remarkable ten, eight and six arrivals per resident. The Dutch city’s appeal may frustrate local officials. In recent years they have sought to stem the flood of tourists by reducing the supply of hotel accommodation, banning cruise ships and raising hotel taxes. In the end, it seems the lure of some lovely canals and gouda cheese, among other things, is too much to overcome.