The GLA’s interim metro area dataset

This paper reproduces, in citable form and, for scholarly purposes, the report of the same name produced by the author for the Greater London Authority. GLA Economics prepared its interim dataset on the output and population of 35 European cities, for use within the GLA group when London is benchmarked against these cities. The need for this dataset arose because there is no agreed standard, either worldwide or in Europe, for measuring a city, or even for defining where it begins or ends. Existing estimates differ widely. In a previous working paper, we compared estimates of city productivity growth available from three sources, and found that the differences between these sources were greater than between the cities themselves. These differences affected such basic questions as, for example, whether German cities were growing faster, or slower, than British cities. Economic conclusions about cities in Europe, in short, depend on who provides the data. Although a number of international agencies are working on this problem, with whom GLA Economics works closely,at the time of publication no agreed standard exists. The GLA therefore prepared this dataset for its own purposes, as a standard against which to judge others and as the basis for its own decisions.