It is now a widely recognised fact in the economic literature that the level of per capita income and the degree of sectoral concentration of economic activity evolve together over the long term. The empirical research of Imbs and Wacziarg (2003) has notably shown that production diversification and wealth go hand in hand in countries with a low per capita income. More recently, various studies have found that export diversification is similarly linked to per capita income (Klinger and Lederman, 2006; Hesse, 2009; Cadot et al., 2011): export diversification increases as per capita income rises, at least up to a certain level of income.
This type of approach, however, does not exhaust the analysis of the phenomenon of export diversification. More specifically, it does not allow an investigation of how export structures evolve over the short and medium term. Yet, these time scales can in fact prove useful to more clearly identify the factors that impede diversification. It is thus on this aspect of export diversification that the present study will focus.