Defining and Measuring Metropolitan Regions: a rationale

This paper was presented an OECD working group of city measurement, in Paris, in November 2006. It presents the rationale for, and a method for measuring, the ‘Functional Urban Region’ of London which establishes an estimate of its true economic extent, independent of its actual or historical boundaries. Noting that there is no consistent definition of the boundaries of ‘economic’ London, and that different suppliers of data work on the basis of definitions that not only conflict, but produce inconsistent and widely different data about London, it applies the FUR-based method developed by the GEMACA group for defining and measuring cities. This system, similar to the SMSA system employed in the USA by the Office of Management and Budget, calculates a core, defined either as a densely populated area or an area with a high job density, and a ‘commuting field’ containing people that regularly travel into or communicate with the core for economic purposes, principally work. It differs from the Urban Audit system in use at the time that this paper was presented, insofar as the UA system uses a mix of administratively defined cores and economically defined commuting fields, and varies the parameters used for both in accordance with local views, leading to a lack of comparability. The paper exhibits the effect of various choices for defining the core and commuting field, and shows that the population of London in 2000 lay somewhere between 12,250,000 and 13,920,000. The final choice of parameters – and the eventual estimate of population – should pay due regard to issues of international compatibility, but the method itself is eminently practical.