Horizontal Inequalities and Ethno-Nationalist Civil War: A Global Comparison

The research argues that both economic and political horizontal inequalities (HIs) are significant drivers of ethno-nationalist civil war. Using a novel combination of geo-coded ethnic settlement data and spatial wealth measures, the authors find that ethnic groups whose wealth deviates significantly from the national average—whether they are relatively affluent or impoverished—are more prone to conflict. This effect persists even when controlling for political exclusion from executive power, which itself is a strong predictor of conflict. The findings challenge contemporary 'opportunity-based' theories of civil war that dismiss grievances, suggesting instead that structural asymmetries act as mobilizational resources for collective violence.

• Ethnic groups with wealth levels that deviate significantly from the national average are more likely to experience civil war, regardless of whether they are wealthier or poorer than the average.
• Both economic and political horizontal inequalities independently and jointly contribute to the onset of civil war.
• Political exclusion from central executive power is a strong and statistically discernible predictor of conflict onset.
• The risk of conflict is highest for groups that are both politically excluded and experience significant economic deviations from the national average.
• The conflict-proneness of relatively wealthy groups is not primarily driven by oil income, as the effect remains strong even when oil wealth is subtracted from the data.
• The identified relationship between horizontal inequality and conflict is more strongly associated with territorial conflicts than with governmental conflicts.
• National GDP per capita and the calendar year (post-Cold War trend) have statistically significant negative effects on the probability of civil war onset.

APA

Cederman, L.-E., Weidmann, N. B., & Gleditsch, K. S. (2010). Horizontal Inequalities and Ethno-Nationalist Civil War: A Global Comparison. Peace Research Institute Oslo. https://cdn.cloud.prio.org/files/89a40c4a-1f96-4a10-9570-51c6f64d3942/Horizontal Inequalities and Ethno-nationalist Civil War A Global Comparison.pdf?inline=true

Chicago

Cederman, Lars-Erik, Nils B. Weidmann, and Kristian Skrede Gleditsch. Horizontal Inequalities and Ethno-Nationalist Civil War: A Global Comparison. Peace Research Institute Oslo, 2010. https://cdn.cloud.prio.org/files/89a40c4a-1f96-4a10-9570-51c6f64d3942/Horizontal Inequalities and Ethno-nationalist Civil War A Global Comparison.pdf?inline=true.

Wikipedia

{{cite report |last1=Cederman |first1=Lars-Erik |last2=Weidmann |first2=Nils B. |last3=Gleditsch |first3=Kristian Skrede |title=Horizontal Inequalities and Ethno-Nationalist Civil War: A Global Comparison |publisher=Peace Research Institute Oslo |date=25 August 2010 |url=https://cdn.cloud.prio.org/files/89a40c4a-1f96-4a10-9570-51c6f64d3942/Horizontal Inequalities and Ethno-nationalist Civil War A Global Comparison.pdf?inline=true |access-date=23 October 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{cederman2010horizontal, author = {Cederman, Lars-Erik and Weidmann, Nils B. and Gleditsch, Kristian Skrede}, title = {{Horizontal Inequalities and Ethno-Nationalist Civil War: A Global Comparison}}, institution = {Peace Research Institute Oslo}, year = {2010}, month = aug, url = {https://cdn.cloud.prio.org/files/89a40c4a-1f96-4a10-9570-51c6f64d3942/Horizontal Inequalities and Ethno-nationalist Civil War A Global Comparison.pdf?inline=true}, urldate = {2026-10-23}, note = {Indexed by Climate Insights Directory} }