In the sprawling urban landscapes of sub-Saharan Africa, towering skyscrapers starkly contrast with labyrinthine slum districts where millions live amidst deprivation and uncertainty. Despite the rapid urbanization transforming the continent, the socioeconomic realities of slum dwellers remain incompletely understood, presenting significant barriers to equitable development. A groundbreaking new study by Li et al., published in Nature Cities in 2025, powerfully addresses this knowledge gap by mapping the prevalence of urban slums and dissecting the often-invisible wealth inequalities within these areas across 32 countries in sub-Saharan Africa.
Urban slums, defined by inadequate access to basic services, precarious housing, and insecure land tenure, house nearly one-quarter of the world’s urban population. Yet, these areas have historically been overlooked in large-scale urban poverty assessments due to data scarcity and methodological challenges. The new study sidesteps these limitations by ingeniously integrating high-resolution geospatial data with detailed household surveys to create the most comprehensive portrait yet of slum settlements and their internal socioeconomic disparities.
Employing satellite imagery analyses alongside ground-level survey data, the researchers developed a robust framework to identify slum prevalence and assess wealth-related inequalities at a fine-grained spatial scale. Their results reveal a staggering figure: over half—54.6%—of the urban population in the 32 studied countries live in slums. This enormous share underscores the urgency for targeted urban policy interventions that address the unique vulnerabilities entrenched in these settlements.
Beyond quantifying slum prevalence, the research exposes deep chasms in wealth within and between slum and non-slum areas. Households residing in slums consistently exhibited markedly lower asset-based wealth indices than their non-slum urban counterparts, reflecting stark disparities in access to resources, infrastructure, and economic opportunities. This finding challenges simplistic dichotomies between slum and formal urban areas, revealing nuanced gradients of inequality that have profound implications for social inclusion.
The longitudinal aspect of the study also offers sobering insights. While the proportion of urban populations living in slums has declined modestly over the past two decades, wealth inequalities within and across these populations have simultaneously intensified. Particularly in countries with large slum populations, the wealth gap has widened conspicuously, suggesting that improvements in housing or infrastructure have not translated into equitable economic advancement for slum residents.
This paradoxical trend raises critical questions about the drivers of urban inequality. The researchers suggest that growth in slum infrastructure and access to services alone may be insufficient to bridge wealth disparities without parallel investments in inclusive economic opportunities, education, and governance reforms. Such multidimensional approaches are essential to fulfilling the United Nations’ sustainable urban development commitments, particularly the pledge to “leave no one behind.”
Methodologically, the study’s use of integrated geospatial and socioeconomic data represents a major advance in urban poverty research. Traditional surveys often suffer from under coverage of informal settlements and lack spatial resolution. By complementing household survey data with remote sensing techniques, the researchers overcame these obstacles, yielding a detailed spatial map of slum extents and internal heterogeneities in wealth levels. This technique enhances the capacity to monitor urban poverty dynamically and guide evidence-based policy responses.
The visualization provided in the study reveals complex, heterogeneous patterns of slum distribution. Urban areas that may appear formally developed on a macro scale often conceal persistent pockets of severe deprivation when examined at neighborhood or sub-neighborhood levels. Such fine-scale analyses are crucial for urban planners and policymakers to identify priority areas for intervention and allocate resources more effectively in diverse urban settings.
Moreover, the study underscores the sheer scale of slum populations in sub-Saharan Africa compared to other regions. Factors such as rapid rural-to-urban migration, limited formal housing supply, and weak urban governance compound to create sprawling informal settlements. These settlements not only lack basic sanitation, water, and electricity but also face systemic exclusion from formal city planning processes, further entrenching cycles of poverty and marginalization.
The implications extend beyond mere demographics or economics. The spatial concentration of wealth inequalities within slums affects health outcomes, educational access, and social mobility, creating intergenerational impacts that perpetuate urban poverty traps. Recognizing these multifaceted consequences is pivotal for designing multidimensional interventions that address health, education, infrastructure, and economic inclusion simultaneously.
International development agencies and local governments stand to benefit profoundly from the data-driven insights offered by this research. By providing an empirical basis for identifying areas of greatest need, the study offers a powerful tool to prioritize investments, monitor progress, and evaluate the impacts of urban poverty reduction programs with greater precision and reliability.
Additionally, the researchers highlight the dynamic nature of urban slums and wealth inequality, advocating for continuous monitoring to capture evolving patterns influenced by economic cycles, climate change, and migration trends. Incorporating up-to-date, high-resolution data into urban governance frameworks will be critical to adapting policies in real time and mitigating emergent vulnerabilities within fast-changing urban environments.
The study also calls attention to the ethical dimensions of urban data collection and use. Sensitive handling of data on vulnerable populations must be prioritized to avoid stigmatization or exclusion. Participatory approaches involving slum communities themselves in data collection and resource planning can foster trust, empowerment, and more sustainable outcomes.
In a broader context, this research contributes to a growing recognition among urban scholars and policymakers that sustainable cities cannot be achieved without addressing entrenched intra-urban inequalities. Slums are not merely statistics or blighted geographies—they are homes to vibrant, resilient communities whose potential remains untapped due to systemic barriers.
By illuminating the complex spatial and socioeconomic mosaics of sub-Saharan African slums, Li et al. provide a crucial foundation for transformative urban policies that reckon with inequality as a central axis, rather than a peripheral concern. Their work heralds a paradigm shift toward evidence-based, inclusive urban development that prioritizes the dignity and wellbeing of all residents, regardless of zip code or housing status.
As the global community advances toward its 2030 Agenda, the insights from this study underscore that the “leave no one behind” promise remains a formidable challenge in sub-Saharan African cities. However, armed with sophisticated data tools and a commitment to nuanced understanding, there is hope that slum residents can secure a more equitable share of the urban future.
In summation, this landmark research offers an indispensable resource for urban policymakers, development practitioners, and scholars seeking to dismantle the persistent inequalities shadowing Africa’s urban transformation. The integration of geospatial technologies with rich household survey data marks a critical methodological and practical leap forward, charting a path to smarter, fairer, and more inclusive cities in the heart of a rapidly urbanizing continent.
Subject of Research: Mapping urban slums and wealth inequalities in sub-Saharan Africa through integrated geospatial and household survey data.
Article Title: Mapping urban slums and their inequality in sub-Saharan Africa.
Article References:
Li, C., Yu, L., Ndugwa, R. et al. Mapping urban slums and their inequality in sub-Saharan Africa.
Nat Cities (2025). https://doi.org/10.1038/s44284-025-00276-0
Image Credits: AI Generated
