Polarization patterns in economic development and innovation

This paper examines the polarization of economic development in African economies. Based on nonparametric and bipolarization frameworks, we find that countries tend to cluster in two classes, and that bipolarization has been accelerating over the period 1966-2008. We relate the evolution of income bipolarization to specialization in a country. The main sectors that tend to reduce income bipolarization are mining and services. We also study the effects of innovation on income polarization. In particular, we analyze short-run and long-run effects of innovation and their inter-relationship with income polarization. We show that the impact of innovation differs depending on its origin and its type. If innovation is resident, then trademarks outweigh patents. On the contrary, if the origin of innovation is non resident, then patents have a greater effect. Moreover, there is an adjustment process between trademarks residents and patents residents. In the short-run, when trademarks residents are too high, they quickly fall back toward patents residents level. We do not observe such adjustments between trademarks non residents and patents non residents. Last, unexpected shocks that affect patents (res. trademarks) have a permanent (res. transitory) effects on income polarization.