This article provides an overview of the theoretical and empirical contributions made by scholars of ethnic politics in Africa. I first discuss the definitions and measures of ethnic politics most commonly used. I then review the main explanations of the prevalence of ethnic politics. The following sections discuss the consequences of politicized ethnicity, variation in ethnic politics, and the relationship between ethnicity and other social identities, such as national identity. I conclude with some remarks about existing gaps and promising future avenues of research.

Existing studies of ethnic voting mainly focus on democratic elections. In electoral autocracies, politically subordinate ethnicity can help citizens coordinate against the incumbent. However, we argue that collective action will be constrained when the group grows large, as it becomes costly for its members to form common behavioural norms and carry out effective sanctions through shared ethnic ties under authoritarian repression. Drawing on unique historical surveys in Taiwan, we study how Taiwanese ethnicity and local ethnic demography jointly induced voters' defection against the hegemonic KMT regime. We find that the pro-defection or anti-incumbent effect of Taiwanese ethnicity fell as the share of Taiwanese citizens in a township increased. However, the relative size of the Taiwanese group no longer undermined pro-defection ethnic voting after the KMT lifted the ban on opposition parties. Our results illustrate that formal organizations play a critical role in sustaining the informational salience of ethnicity in the elections.

Ethnic voting is an important phenomenon in the political lives of numerous countries. In the present paper, we propose a theory explaining why ethnic voting is more prevalent in certain localities than in others and provide evidence for it. We argue that local ethnic geography affects ethnic voting by making voters of ethnicity that finds itself in the minority fear intimidation by their ethnic majority neighbors. We provide empirical evidence for our claim using the data from round 4 of the Afrobarometer survey in Ghana to measure the voters’ beliefs that they are likely to face intimidation during electoral campaigns. Using geocoded data from rounds three and four of the Afrobarometer, as well as data from the Ghana Demographic and Health Survey, we find no evidence for local public goods provision as an alternative mechanism.

The existing literature has demonstrated that both ethnic and economic factors affect a vote decision in African democracies. I show that there is a meaningful interaction between the two cleavages in their influence on voting. In particular, I argue for political salience of agricultural subsectors that shape the electoral consequences of economic performance in the context where agricultural policy affects the livelihood of the majority population. Relying on the analyses of the 2007 and 2013 elections in Kenya, I illustrate how likely an individual, who is attached to a politically coherent ethnic group, votes for a candidate, the majority of whose ethnic members engage in the same industry as the voter himself regardless of the candidate's ethnicity. The results show that the sector factor reinforces the positive and negative effects of ethnic communities on incumbent support, and also explains voting by ethnic minorities whose motives for voting are not ethnic.

Prospects for democracy in multi-ethnic societies are generally more promising if elections are not mere ethnic censuses, in which people vote predominantly for co-ethnic parties and candidates. But what institutions facilitate or hinder ethnic voting? Unlike past studies, this article explores ethnic voting by conducting a natural experiment (rather than surveys or laboratory experiments). It examines the case of Fribourg, a bilingual (French/German) Swiss canton where elections at different levels of government, within the same electoral district, are held under both majoritarian and proportional systems. Coupled with the high territorial homogeneity of the linguistic groups, this unique setting allows us to conduct a robust empirical analysis of voter behaviour. We find that cross-ethnic voting is significantly more frequent in multi-member majoritarian elections than in list-PR elections or in two-member majoritarian elections. Our results yield qualified support to the centripetalist approach to electoral design in multi-ethnic societies, that favours majoritarian systems, rather than to the consociational school that advocates proportional representation.

How does wartime exposure to ethnic violence affect the political preferences of ordinary citizens? Are high-violence communities more or less likely to reject the politicization of ethnicity post-war? We argue that community-level experience with wartime violence solidifies ethnic identities, fosters intra-ethnic cohesion and increases distrust toward non-co-ethnics, thereby making ethnic parties the most attractive channels of representation and contributing to the politicization of ethnicity. Employing data on wartime casualties at the community level and pre- as well as post-war election results in Bosnia, we find strong support for this argument. The findings hold across a number of robustness checks. Using post-war survey data, we also provide evidence that offers suggestive support for the proposed causal mechanism.