This paper explores three different hypotheses about the role of ethnicity in voting behavior. The first sees ethnic voting as a primarily expressive act, a means of aligning oneself with a broader movement/party that represents the group with which one identifies. The second sees voting as a straightforward selection between policy options, with ethnicity working behind the scenes to align the policy preferences of group members. The third sees the primary role of ethnicity as informational, as providing a sufficient statistic that helps voters make decisions about electoral options under conditions of uncertainty. Thus, in the first case, the immutability of ethnic census outcomes depends on identity; in the second, on policy; and in the third, on information and beliefs. These suggest different pathways for the erosion of ethnic census outcomes. After laying out these hypotheses, the paper tests them using data from South Africa. It finds little support for the first and second hypotheses, but considerable support for the third one.