The degree of urbanisation classification defines cities, towns and semi-dense areas, and rural areas. This document details the methodology. We use the degree of urbanisation typology for international comparison and in thematic work. Recent work includes Cities in the World: A New Perspective on Urbanisation and Regional Development along the Settlement Network.
OECD Geographical Definitions
International comparisons of subnational data require consistent frameworks. We provide such definitions and typologies for regions, cities and rural areas.
Overview of definitions
Definition of cities, towns and rural areas
Defining cities and functional urban areas
The OECD definition of functional urban areas (FUAs) captures meaningful connections between cities and their surrounding areas. The definition expands city boundaries to include economically connected areas. The OECD cities and functional urban areas database publishes indicators for FUAs.
Defining regions and territorial levels
Regions are subnational units below national boundaries. We define two territorial levels: large regions (TL2) and small regions (TL3). This classification facilitates comparability of geographic units across countries.
The OECD Territorial grid (pdf) and in the OECD Territorial correspondence table (xls) present the regions.
Territorial typologies
The OECD typology on access to cities offers a way to group small regions based on their population density and their distance to dense places. This document offers more details on the methodology.
The urban-rural typology offers another way of grouping small regions. The access to city typology has largely superseded this typology in OECD analyses.
The OECD regional database contains indicators by typology.
