Demographic dynamics, urban expansion, and social inclusion in Burkina Faso's small towns (1985-2019): A context-aware decoupling analysis

International audience Small towns constitute most of Africa's urban settlements, yet their spatial dynamics remain poorly understood in relation to demographic change, land-use efficiency, and social inclusion. Existing decoupling models overlook initial land-consumption conditions, path dependence, and broader urban subsystem behavior. This study examines 98 small towns in Burkina Faso through five analyses: growth trajectory clustering, Gibrat's law testing, land-population elasticity modeling, a benchmark-adjusted Tapio decoupling framework, and social outcome assessment. Results reveal sustained urban growth with two accelerated built-up expansion waves (1995-2000 and 2015-2019), reflecting decentralization policies, real-estate liberalization, and conflict-induced internal displacement. Four persistent growth regimes emerge, reflecting administrative status, accessibility, metropolitan influence, and local socioeconomic conditions. Population growth is largely size-independent, while the population-built-up relationship progressively converges toward proportionality (β = 0.96), indicating increasing spatial-demographic coherence. Persistent outliers highlight the influence of conflict, migration, mining activity, and geographic isolation. Against Burkina Faso's national benchmark of 75 m² per capita, the share of towns exhibiting inefficient land expansion increased from 40% (2005-2010) to 78% (2015-2019). Although some land-use efficiency indicators are statistically associated with poverty incidence, they explain no meaningful share of the observed variation in poverty and wealth inequality. Context-aware efficiency classes show no significant relationship with either indicator. These results suggest that compliance with land-use benchmarks does not automatically translate into social inclusion. By integrating demographic, spatial, institutional, and social dimensions, this study proposes a replicable framework for diagnosing urban expansion in data-scarce regions and highlights the need for context-sensitive, governance-aware land-use policies in rapidly urbanizing small-town systems.