Once we establish the existence of a relationship between party competition and levels of ethnic violence, an obvious question follows: if party competition is so important, then what explains states' different levels of party competition? Why do some states have party systems that reflect a greater degree of cohesion around backward-caste identities than others? Why, in particular, did some southern states in India such as Kerala and Tamil Nadu have an effective opposition to Congress by the early 1960s, well before states in the north such as Uttar Pradesh and Bihar?

My central argument in this chapter, laid out in Figure 6.1, is that an institutional difference going back to the 1920s – the implementation of job and educational reservations for backward and lower castes in the South but not in the North – is largely responsible for different state patterns of postindependence party competition and fractionalization. In the early 20th century, after the colonial state and several princely states in southern India grouped members of diverse castes together under a backward-caste identity, they provided political and economic incentives for Indians to mobilize around this identity, which has been sustained since then not only by government affirmative action programs but also by social and political organizations that grew up in response to the governments' willingness to reward claims made on the basis of “backwardness.”