We provide a set of territorial definitions to maximise international comparability of statistical indicators related to sub-national and local units (i.e. cities, regions, rural areas, etc.) and enhance solid analysis of spatial issues.
Comparing cities, regions or other types of local areas in different countries is a challenging task. For example, national definitions of cities are rarely consistent across countries and they rely on administrative or legal boundaries that are very different in size and not necessarily comparable across countries. Similarly, national defitions do now always align in defining of what a city, a rural area or a metropolitan area is.
Regional statistics and metropolitan stastistics are crucial tools for the analysis of regional development issues carried out by the OECD and by the scientific community in the field. The users of statistics have expressed a growing need for harmonisation of statistical indicators for all OECD countries.
The OECD offers a set of territorial definitions and classifications at different scales for OECD member countries and beyond. Those definitions are based on analysis and exchanges with experts and on the consensus reached among countries, also through the Working Party on Territorial Indicators of the OECD Regional Development Policy Committee.
The major definitions available are the following:
- OECD Territorial Grid. It provides the list of sub-national regions in all OECD countries. Sub-national regions are classified in two scales, the large regions (Territorial Level 2, TL2) and the small regions (Territorial Level 3, TL3). Large regions generally correspond to the first government layers after the national or federal one. Small regions are contained within large regions and, in the case of European countries, they correspond to the NUTS3 nomenclaure. The OECD publishes regularly statistical indicators for both small and large regions in the OECD Regional Database. [Document]
- Functional Urban Area (FUA). Developed in collaboration with the European Union and endorsed at the 2020 Statistical Commission of the United Nations, FUAs consist of cities together with their surrounding commuting zones. This definition looks at the full extent of cities’ labour markets to capture the economic boundaries of cities. In many contexts, FUAs are called ‘metropolitan areas’ because they include a commuting zone to the city. FUAs are generally aggregation of local units (i.e. municipalities, local authorities, etc.). Statistical indicators are regularly published for FUAs above 250,000 inhabitants in the OECD Metropolitan Database. [Method] [Boundaries]
For analytical purposes, we have developed also an estimation of the world metropolitan areas (eFUAs) based solely on population grids, where local unit boundaries are not considered [Method] [Boundaries].
- Urban-rural regional classification: it classifies all small regions into predominantly urban, intermediate, and predominantly rural, based on population density at grid level. Predominantly rural regions are in turn distinguished in close to a city or remote [Method].
- Metro/non-metro classification: It classifies all small regions into five groups: ‘large metropolitan’, ‘metropolitan’, ‘with access to a metro’, ‘with access to a small-medium city’, ‘remote’. [Method].
- Labour Market Area (LMA): LMAs are aggregation of local units based on self-containment of commuting flows. They cover the entire national territory and have been delineated for selected OECD countries [Report].
For further information, please contact Paolo.VENERI@oecd.org or regionStat@oecd.org.