Cash Crops, Print Technologies, and the Politicization of Ethnicity in Africa.

What are the origins of the ethnic landscapes in contemporary states? Drawing on a preregistered research design, we test the influence of dual socioeconomic revolutions that spread throughout Africa during the nineteenth and twentieth centuries—export agriculture and print technologies. We argue these changes transformed ethnicity via their effects on politicization and boundary-making. Print technologies strengthened imagined communities, leading to more salient—yet porous—ethnic identities. Cash crop endowments increased groups' mobilizational potential but with more exclusionary boundaries to control agricultural rents. Using historical data on cash crops and African language publications, we find that groups exposed to these historical forces are more likely to be politically relevant in the postindependence period, and their members report more salient ethnic identities. We observe heterogenous effects on boundary-making as measured by interethnic marriage; relative to cash crops, printing fostered greater openness to assimilate linguistically related outsiders. Our findings illuminate not only the historical sources of ethnic politicization but also mechanisms shaping boundary formation. [ABSTRACT FROM AUTHOR]