A large and growing literature links high levels of ethnic diversity to low levels of public goods provision. Yet although the empirical connection between ethnic heterogeneity and the underprovision of public goods is widely accepted, there is little consensus on the specific mechanisms through which this relationship operates. We identify three families of mechanisms that link diversity to public goods provision—what we term “preferences,” “technology,” and “strategy selection” mechanisms—and run a series of experimental games that permit us to compare the explanatory power of distinct mechanisms within each of these three families. Results from games conducted with a random sample of 300 subjects from a slum neighborhood of Kampala, Uganda, suggest that successful public goods provision in homogenous ethnic communities can be attributed to a strategy selection mechanism: in similar settings, co-ethnics play cooperative equilibria, whereas non-co-ethnics do not. In addition, we find evidence for a technology mechanism: co-ethnics are more closely linked on social networks and thus plausibly better able to support cooperation through the threat of social sanction. We find no evidence for prominent preference mechanisms that emphasize the commonality of tastes within ethnic groups or a greater degree of altruism toward co-ethnics, and only weak evidence for technology mechanisms that focus on the impact of shared ethnicity on the productivity of teams.

This paper explores the conditions under which cultural cleavages become politically salient. It does so by taking advantage of the natural experiment afforded by the division of the Chewa and Tumbuka peoples by the border between Zambia and Malawi. I document that, while the objective cultural differences between Chewas and Tumbukas on both sides of the border are identical, the political salience of the division between these communities is altogether different. I argue that this difference stems from the different sizes of the Chewa and Tumbuka communities in each country relative to each country's national political arena. In Malawi, Chewas and Tumbukas are each large groups vis-à-vis the country as a whole and, thus, serve as viable bases for political coalition-building. In Zambia, Chewas and Tumbukas are small relative to the country as a whole and, thus, not useful to mobilize as bases of political support. The analysis suggests that the political salience of a cultural cleavage depends not on the nature of the cleavage itself (since it is identical in both countries) but on the sizes of the groups it defines and whether or not they will be useful vehicles for political competition.

This paper draws on data from over 35,000 respondents in twenty-two public opinion surveys in ten countries and finds strong evidence that ethnic identities in Africa are strengthened by exposure to political competition. In particular, for every month closer their country is to a competitive presidential election, survey respondents are 1.8 percentage points more likely to identify in ethnic terms. Using an innovative multinomial logit empirical methodology, we find that these shifts are accompanied by a corresponding reduction in the salience of occupational and class identities. Our findings lend support to situational theories of social identification and are consistent with the view that ethnic identities matter in Africa for instrumental reasons: because they are useful in the competition for political power.

With the rise of analytical or positive approaches to the study of politics over the last three decades, the collective action problem has emerged as one of the central concepts in political science. The concept's widespread acceptance as a descriptive and diagnostic tool, however, cannot obscure the fact that its predictions do not always hold. Co-operation sometimes does take place in contexts where, according to the theory, actors should have little incentive to engage in it.To account for such behaviour, theorists have developed the concept of social capital. 1 Although authors define it in various ways, social capital is, at its core, a set of institutionalized expectations that other social actors will reciprocate co-operative overtures. 2 This expectation generates co-operation by making otherwise uncooperative actors willing to undertake those overtures in the first place.Both the academic and policy-making communities have been energized by the concept of social capital. From the World Bank to city hall, the creation of social capital has been embraced as a solution for social problems as diverse as urban poverty and crime, economic underdevelopment and inefficient government. 3 Yet despite the widespread attention it has received, our theoretical understanding of the concept of social capital is still in its infancy. The purpose of this Note is to identify and discuss two particularly weak aspects of the social capital research paradigm. The first is the question of the origins of social capital. Although we know that social capital stocks vary across countries and communities, we currently have a poor understanding of how to explain this variation. The second is the issue of accounting for the mechanisms that link social capital with good performance in government. Although the accumulated evidence strongly suggests that the two are correlated, we lack an understanding of the microlinkages that connect one with the other.