Inflation-adjusted rental housing affordability: diverging RIR trends across Lagos, Kumasi and Johor Bahru

Purpose Rental housing affordability has become a critical challenge in rapidly urbanising cities, particularly under conditions of inflation, income volatility and uneven institutional capacity. This study aims to examine inflation-adjusted rent-to-income ratios (RIRs) in Lagos, Kumasi and Johor Bahru between 2020 and 2025 and analyses how income dynamics, macroeconomic conditions and housing policy frameworks jointly shape rental affordability outcomes. Design/methodology/approach This study adopts a comparative quantitative design, combining household survey data from 900 renter households with secondary macroeconomic indicators. Nominal household incomes were deflated to constant 2020 prices using cumulative CPI deflators, and weighted averages were derived from class midpoints. RIRs were computed and analysed longitudinally. A Kruskal–Wallis test was used to assess inter-city differences. Findings The results reveal sharply divergent trajectories of affordability. Lagos and Kumasi experienced severe deterioration in rental affordability as inflation, currency depreciation and weak wage growth eroded real incomes while rents escalated rapidly, pushing RIRs far beyond conventional affordability thresholds. In contrast, Johor Bahru maintained stable and affordable rent–income relationships, supported by moderated inflation, rising real incomes and co-ordinated housing policy interventions. Statistical tests confirm significant differences between Johor Bahru and the two West African cities, while Lagos and Kumasi exhibit comparably high rent burdens. Research limitations/implications The findings highlight the importance of incorporating inflation-adjusted measures and institutional context into affordability analysis, particularly in high-inflation urban environments. Originality/value This study advances housing affordability research by developing a comparative, inflation-adjusted framework that identifies three urban rental affordability regimes: persistent extreme stress, progressive deterioration and institutional stabilisation, demonstrating that extreme rental stress is institutionally contingent rather than inevitable.