Land economic rent computation for urban planning and fiscal purposes

This article proposes an innovative methodology to compute economic rents of land designed to current or potential offices uses. It consists in the establishment of a cause-and-effect relation between offices’ price levels and correspondent levels of land rent, considering the main factors that influence property prices, the ones that guide public and private activities’ location decisions and the inter-dependencies between land and real estate property markets. The rationale subjacent to this research is that land economic rent is determined by the difference between offices market price and a set of costs correspondent to land acquisition, planning and building processes, and a profit margin. An assessment of surplus values is provided in order to compute it as the difference between total land market value (land economic rent plus economic return on land use) and correspondent tributary patrimonial-value according to legal valuation proceedings (settled on property law). In order to reach these goals, variables that exert influence on urban planning and municipal management were identified, an urban management information system was designed and implemented, and an integrated and interactive model to support decisions in urban planning – concerning real estate offices and land prices and characteristics – was developed. These tools were applied as a case study to Oporto city (Portugal). They embody updating functionalities, setting up as an on-going support to policies of municipal land use management (particularly applied to offices uses). A proposal is made to integrate similar models in territorial plans as valuation tools to support better approaches to assess the impact of planning decisions on real estate and land values, thus informing a more equitable, efficient and local-based tax basis. Implications of this analysis for urban planning and fiscal settings are proposed.