Economics
The Influence of Ethnic Fractionalization on Civil War Onset
Quick fact
In a landmark 2003 study, Fearon and Laitin found that ethnic fractionalization was not a significant predictor of civil war onset, whereas per capita income and political instability were.
Why this is interesting
If a country is more ethnically diverse, you’d expect more civil wars – but the data show the opposite. How can that be?
Read the full explanation
Understanding The Influence of Ethnic Fractionalization on Civil War Onset
Ethnic fractionalization is a simple measure: the probability that two randomly chosen people in a country belong to different ethnic groups. A value of 0 means everyone belongs to one group; a value close to 1 means dozens of tiny groups. Researchers often use the Ethnolinguistic Fractionalization Index (ELF), based on old Soviet-era data. Intuitively, you might think a higher score means more potential flashpoints. But the classic study by Fearon and Laitin (2003) tested this and found that once you control for factors like per-capita income and political instability, ethnic fractionalization loses its power. In fact, many highly diverse countries like Tanzania have stayed peaceful, while relatively homogeneous states like Rwanda fell into genocide. The key is that ethnic diversity alone doesn't cause war; it depends on how groups are treated, the capacity of the state, and opportunities for rebellion.
A deeper explanation
The initial reason for the null result is that civil wars are not primarily caused by ethnic differences per se, but by the feasibility of rebellion. Ethnic fractionalization measures how many groups exist, but it does not capture the political salience of ethnic identities. When one group, like the Tutsi in Rwanda, holds disproportionate power, conflict risk rises. Fearon and Laitin argued that state strength (low income, difficult terrain) matters more. In contrast, some later studies using alternative indices—like the one by Alesina et al.—found that ethnic fractionalization can be linked to poor economic performance, which indirectly raises conflict risk. The paradox thus arises from measurement and from the distinction between having many groups versus a single dominant group that faces a minority. The concept forces us to think about what diversity really means for social cohesion and conflict.