Migration's contribution to the urban transition: Direct census estimates from Africa and Asia

Background: The components of urbanisation are important to understand, since urbanisation is closely related to development. Internal migration was key in historical urban transitions, while in contemporary transitions the balance of births and deaths has been the main driver of urbanisation. Reclassification of rural areas and international migration also contribute to urbanisation. Objective: Unlike previous work based on indirectly measured net migration estimates, we directly estimate in- and out-migration rates between rural and urban areas across Africa and Asia by age and sex, and evaluate the contribution of the balance of these flows to urbanisation. Methods: We use 67 census samples from IPUMS International for 28 countries in Africa and Asia between 1970 and 2014 to estimate in- and out- migration between rural and urban areas, based on available questions of residence. We then model age- and sex-specific migration rates using Poisson regression and estimate net migration through marginal effects. Results: Results confirm that, in both continents, urbanisation is not generated by rural-to-urban migration but by the urban population itself, be it through natural growth or through expansion to peripheral areas. In Asia, urbanisation reflects internal migration trends and reclassification decisions to a greater extent than in Africa, where natural growth is the key contributor. Conclusions: In Asia, urbanisation reflects internal migration trends and reclassification decisions to a greater extent than in Africa where natural growth is the key contributor. Contribution: By using direct estimates, we ascertain the role of inter-regional rural-urban migration in urbanisation. We find that a positive effect of inter-regional migration is counter-balanced by a negative effect of intra-regional migration (combined with reclassification and international migration)

The dynamic role of household structure on under-5 mortality in southern and eastern sub-Saharan Africa

Background: Children are born and grow up in households, where they receive essential care, including time, socio-psychological support, and economic resources. Children's immediate environment, captured by household structure, changes over time. Objective: We evaluate the role of dynamic household structure in the risk of child death in southern and eastern Africa. Methods: We use longitudinal data from 15 Health and Demographic Surveillance Systems between 1990 and 2016, covering almost 282,000 under-5 year olds. We analyse under-5 mortality using semi-parametric Cox models accounting for time-varying household structure (household size and household typology) and controlling for maternal characteristics. Results: We find that children in smaller households have a higher risk of death than those in large households. In particular, children in households where they are the sole child with two adults of opposite sexes have the lowest chances of survival, reflecting a first-child effect. By contrast, nuclear-type households with more than one child are the most protective, while children in extended households are more vulnerable. Contribution: Our findings suggest that the (in)stability of households is important in evaluating child survival, and that it is imperative to consider households as changing entities

Migrant-based youth bulges and social conflict in urban sub-Saharan Africa

BACKGROUND Sub-Saharan Africa has experienced relatively high population growth, which raises concerns about the potential contribution of large young cohorts, termed ‘youth bulges’, to unrest. Youth bulges, under the right circumstances, can expand productivity and boost economic growth, but they have also been found to enable civil war, corruption, and democracy collapse, especially where resources are scarce. OBJECTIVE This paper considers youth bulges characterised by high proportions of rural‒urban migrants and examines their effects on the likelihood of social conflict in urban sub- Saharan Africa between 1990 and 2013. METHODS United Nations data on urban and rural populations by age and sex is combined with the Social Conflict Analysis Database to create a cross-section time series dataset. Negative binomial models are used to examine the relationship between youth bulges and conflict using country level fixed effects. RESULTS The study finds that a migrant-based youth bulge does not increase the likelihood of urban social conflict in sub-Saharan Africa. Additionally, female youth bulges, often neglected when studying conflict, are found to increase the likelihood of conflict. CONCLUSIONS The overall disassociation between young rural‒urban migrants and social conflict is encouraging. All the same, women were found to play a role in conflict, and women should therefore be considered in future studies. CONTRIBUTION This article characterises the composition of youth bulges – an important factor that has previously been ignored ‒ by examining whether youth bulges composed largely of rural‒urban migrants are more likely to increase the likelihood of conflict in urban sub- Saharan Africa

The more the healthier? Accounting for the dynamic role of household structure in child mortality in sub-Saharan Africa

Households are the backbone of societies, as the centre of a myriad of processes including childbearing, labour force participation and health care. Understanding the dynamics of households is thus important, yet little research examines the implications of living arrangements in sub-Saharan Africa, including how household structure may affect the health and mortality of children. While parents play a critical role in their children’s survival, other household members have also been found to provide support for children, reducing child mortality. We examine the effect of household structure on child mortality between 1990 and 2015 in sub-Saharan Africa where mortality remains highest and households are relatively large. Using readily available data from 27 Health and Demographic Surveillance Systems which cover entire populations in delineated areas, we examine households as time-varying entities. The pooled data includes over 500,000 under-five year olds. We use Cox proportional hazard models, controlling for site and period effects, to evaluate the impact of household size, the ratio of men to women in the household and the presence of specific members, such as older women (grandmothers) who may help care for children, on under-five mortality. We also consider whether the effect of the presence of mothers differs to the effect of the presence of fathers on child mortality. Our preliminary findings indicate that households are becoming smaller in sub-Saharan Africa, but larger households have a protective effect for children. Additionally, more women in the household lowers the risk of child mortality

The roles of internal migration and natural growth in the urban transition in sub-Saharan Africa, 1975-2015

Sub-Saharan Africa (SSA) is the least urban region of the world where the urbanisation process has slowed down. In light of this, we aim to identify the disparate contribution of demographic forces (rural-urban migration and natural increase) to urbanisation and examine the trends in the roles they play in urbanisation in SSA over the past 40 years. Using multiple data sources, including 39 censuses, covering all regions of SSA between 1976 and 2016 we directly estimate rural-urban migration flows. We further examine the role of migration in urbanisation by breaking down the urban sector into capital city compared to other urban settlements allowing a more nuanced understanding of migration trends. We find that natural increase is negligible at the beginning of the urban transition in SSA, and then becomes dominant once the percent urban exceeds 30%. In contrast, the contribution of rural-urban migration declines. While the rural population is losing migrants to capital and urban areas at around 1% a year, the contribution to urban growth is diminishing. Additionally, we find that net-migration rates between the capital to other urban settlements are low and relatively stable over time and urbanisation level