In the previous chapter I present an uncritical, selected review of the world cities literature. In fact, of course, this literature is highly contested in several respects – see, for instance, the critical discussions by Soja (2000: chapter 7) and Smith (2001: chapter 3). The starting point of this chapter is a particular critique that I believe to be absolutely fundamental to any further advances in the understanding of world cities. My critique concerns the world city literature’s evidential basis. In particular, I argue that there is an acute empirical deﬁcit for studying the external relations of cities. As I have shown, there are numerous statements in the literature about inter-city relations at the global scale but when these are investigated they are often based upon the ﬂimsiest of empirical evidence. This is a quite remarkable state of affairs given the supposed nature of world cities as components of global hierarchies and networks. The ﬁrst section of the chapter illustrates the extent of the problem; the rest of the chapter reﬂects on the implications of this situation.