Before reading chapter 9, the introduction of an endogenous frontier had proved to be a useful tool in my economic history classes, helping undergraduates, trained in 2 × 2 trade models, make sense of the late nineteenth-century apparent paradox: the prima facie evidence that labour and capital flowed in the same direction, while at the same time the volume of international trade rapidly increased. After reading Collins et al., I will have to revise my syllabus. Or will I?

It was over 10 years ago when Jeff Williamson embarked upon what soon became a major effort in describing, understanding and explaining the multifarious aspects of the so-called ‘first globalisation’ – the one, that is, that came to an abrupt end in August 1914. Since then, Williamson and his numerous co-authors have patiently constructed an incredibly large database on flows of goods, labour and capital as well as on prices of products, factors of production, transport and communication services. Armed with such a powerful tool, they set out systematically to tackle the many convergence issues underlying the very notion of globalisation. This effort resulted in an incredibly large output of papers – only few of which feature as references to this chapter – dealing in the first place with individual markets and then, as in the present case, with the interaction among markets.