Customary Land Conversion and the Formation of the African City

As cities grow and spatially expand, agricultural land is converted into residential land. In many developing countries, especially in Sub-Saharan Africa, this process is accompanied by a change in land tenure, whereby plots held under traditional customary arrangements are sold to new urban residents, possibly with formal property rights. This paper studies joint land-use and land-tenure conversion in an urban economics model in which intermediaries purchase agricultural land from customary owners and attempt to transform it into residential plots with statutory property rights. The spatial equilibrium includes a mix of land uses and rights where statutory and non-statutory residential plots coexist with customary land that is mainly used for agriculture. Because customary ownership is subject to uncertainty (because of tenure insecurity), the conversion process includes a potential information asymmetry between customary owners and intermediaries. The analysis shows that a market failure may emerge whereby some customary owners prefer to continue farming their land rather than participate in the urban residential land market, which results in a city that is too small. Empirical analysis using Malian data validates the key features of the model captured by land price gradients, as well as the ranking and the variance of land prices, and is suggestive of the presence of information asymmetry.