On the patterns and determinants of the global diffusion of new technologies

Taking a largely empirical approach this paper addresses the global spread of new technologies by defining two diffusion margins - the extensive, referring to the spreading of first use across economies and the intensive, referring to the intensity of use within economies. Using data relating to mail services we indicate the relative importance of the intensive and extensive margins in global diffusion over time. Using data on steamships and the basic oxygen process for steelmaking we also explore whether there are international spillovers in the diffusion process. We find evidence of spillovers which appear more likely to be negative than positive.