Academic mobility has existed since ancient times. Recently, however, academic mobility--the crossing of international borders by academics who then work "overseas"--has increased. Academics and the careers of academics have been affected by governments and institutions that have an interest in coordinating and accelerating knowledge production. This article reflects on the relations between academic mobility and knowledge and identity capital and their mutual entanglement as academics move, internationally. It argues that the contemporary movement of academics takes place within old hierarchies among nation states, but such old hierarchies intersect with new academic stratifications which will be described and analysed. These analytical themes in the article are supplemented by excerpts from interviews of mobile academics in the UK, USA, New Zealand, Korea and Hong Kong as selected examples of different locales of academic capitalism.