This paper investigates the relationship between socioeconomic horizontal inequalities (inequalities between identity groups, HIs), regime type, electoral system, political exclusion of minorities and civil conflict onset. A positive link between HIs and violent conflict has been established by some preliminary empirical studies, but no systematic large-N study has to date investigated whether and how the political environment can affect this relationship. Using Demographic and Health Surveys (DHS) from 55 developing countries in the period 1986-2003, I calculate welfare inequalities between ethnic, religious, and regional groups based on indicators such as household assets and educational levels. All the HI measures are positively associated with conflict, but the effects seem to be most robust when using the regional group identifier. The regional HI measures are interacted with terms for regime type, electoral system, and political exclusion. The results show that the conflict potential of regional HIs is stronger for democracies and semidemocracies than for autocracies. Institutional arrangements also seem to matter since the positive effect of socioeconomic HIs on civil war increases with the level of inclusiveness of the electoral system. Furthermore, the interaction between political exclusion and socioeconomic regional HIs seems to make countries particularly at risk of conflict. In sum, this suggests that what is required to secure peace in developing countries is the combination of politically and economically inclusive government.
Østby, G. Horizontal Inequalities, Political Environment and Civil Conflict: Evidence From 55 Developing Countries. (2006)