Several authors have argued that ethnic fragmentation has a negative impact on level of economic performance, in particular Easterly and Levine (1997) and, among others, Alesina et al. (2003) using alternative measurements ofethnic fragmentation. However, this negative relationship has been debated with regard to the use of different criteria to delineate ethnic groups and of different measures of ethnic fragmentation. First, some authors have underlined how difficult the definition of ethnic groups is and have challenged the data sources as well as the mathematical tools used to measure ethnic fragmentation (Fearon, 2003, Posner, 2004).
