What policies would help bring unit costs down? The starting point might be a realistic estimate of affordability generated from urban budget survey data. While the results would differ by city, they would reset norms, forcing difficult tradeoffs to the fore. A similar exercise could price the minimum cost of complying with current building standards. A discrepancy between these numbers would force policy discussion. The cost chain could then be benchmarked, component by component, on costs in low-income countries elsewhere in the world, again making differences apparent. Other approaches are to discuss with small, formal building firms the key impediments to lower costs and to undertake quantitative surveys of firms’ cost and productivity differences.

# **Legal rights**

Legal rights affect the housing market in three respects: the ownership, security and marketability of land rights; the extent to which housing can function as collateral; and the rights of tenants relative to landlords.

## **_Land rights_**

Urbanization creates value, and rising density increases productivity. Because the effect is location-specific, much of the increase in value accrues to the owners of urban land. The growth of cities is a classic coordination phenomenon, and so the enhanced value is not readily attributable to the actions of any single agent. But coordination, whether planned or spontaneous, is to a considerable extent the result of public action. Hence, there are reasonable ethical grounds for assigning the ownership of value addition to a city authority as the representative of the residents who have collectively generated it. This has been the strategy in Chinese urbanization that has enabled the finance of urban infrastructure. By contrast, as noted above, in Africa the ownership of prime urban land has often been appropriated by politicians on a speculative basis. This appropriation is recent, as rights of possession of rural land did not extend to marketability and were often further circumscribed by being partially under the authority of chiefs. In turn, the authority vested in chiefs reflected their functions as leaders of their communities. This history reinforces the ethical case for socializing much of the increase in urban land values. However, the most straightforward way to capture these land value gains would be not to reassign land ownership but to use the tax system.

While African urban land rights have often been privatized, they have seldom been clarified. In some cities, such as Freetown in Sierra Leone, a history of dysfunctional registration has left land ownership radically unclear. The same piece of land may have several claimants, each supported by some sort of documentation. Clearly, the number of claimants to a plot is likely to increase in response to construction because ownership becomes more valuable. The rights to property constructed on the plot follow directly from the rights to the plot. Resolution of these disputes through the court system is neither reliable nor swift. Indeed, the legal basis for settlement is often still in dispute. For example, in Ghana lawyers have been attempting to resolve the rules of urban land rights for four decades. In other cities, de facto ownership is