Urbanisation and the political demography of African cities

• Political demographers link large (urban) youth cohorts to individual political behaviour. • We argue that the local demographic context of a city shapes the probability of voting and protest mobilisation of for the individuals within it. • We find that high city youth shares are not associated with individual voting behaviour. • However, we find that individuals living in cities with high youth shares are less likely to protest. • While this holds for all age groups, the age-group gap is wider in cities with more youthful age compositions. Africa is undergoing a rapid process of urban demographic change. Increasingly youthful population structures are defining the continent’s towns and cities. Scholarship suggests this will be associated with greater protest incidence and lower levels of voting and electoral participation. However, these findings often rely on national-level data, despite there being considerable subnational variation in population structures between African cities. Building on existing theory, we argue that local demographic contexts matter for political behaviour. Specifically, we hypothesise that youthful urban demographic structures will be associated with lower levels of formal political participation (voting) and greater levels of informal contentious mobilisation (protest) for all individuals, and that the magnitude of this effect will be greater for younger people. We test these expectations using novel geospatial data on the spatial extent of unique urban settlements, urban-level age and sex structures, and geolocated individual-level survey data from 399 cities in 36 countries across Africa. Using multilevel regression, we find that individuals are more likely to vote in more youthful urban contexts, with young people no more or less likely to vote than their older counterparts. Conversely, we find no significant relationship between individual protest participation and city youth shares overall. However, young people in more youthful cities are significantly more likely to protest than older people. In light of these findings, we discuss how the demographic composition of individual cities in Africa nuances our understanding of political behaviour and contentious mobilisation.