We analyze demand for prepaid cellular voice and short message service (SMS) in South Africa by means of a demand-and-supply structural model based on a multinomial specification fitted to a cross-sectional data set on Vodacom customers collected in 2005. We find that consumers are very...

We develop a diagrammatic framework that can be used to study the economic linkages between regions or cities. Hitherto, such linkages have not been the primary focus of either the theoretical or empirical literatures. We use the framework to analyse the impact of shocks that occur in one region...

We consider the literatures on urban systems and New Economic Geography to examine questions concerning agglomeration and how areas respond to shocks to the economic environment. We first propose a diagrammatic framework to compare the two approaches. We then use this framework to study a number...