Population is unevenly distributed among regions within countries. Differences in climatic and environmental conditions discourage human settlement in some areas and favour concentration of the population around a few urban centres. This pattern is reinforced by the higher economic opportunities and wider availability of services stemming from urbanisation itself.

Definition

The number of inhabitants of a given region, i.e. its total population, can be measured as either its average annual population or as the population at a specific date during the year considered. The average population during a calendar year is generally calculated as the arithmetic mean of the population on 1 January of two consecutive years, although some countries estimate it on a date close to 1 July.

The index of geographic concentration offers a picture of the spatial distribution of the population. It compares the share of population and land area over all regions in a given country, and it takes into account both within- and between-country differences in the size of all regions. This index lies between 0 (no concentration) and 100 (maximum concentration) and is suitable for international comparisons.

Comparability

The main problem with economic analysis at the sub-national level is the unit of analysis, i.e. the region. The word “region” can mean very different things both within and among countries, with significant differences in area and population.

The smallest OECD region (Melilla, Spain) has an area of 13 square kilometres whereas the largest region (Northwest Territories and Nunavut, Canada) has an area of over 3 million square kilometres. Similarly, the population across OECD regions ranges from about 400 inhabitants in Balance ACT (Australia) to more than 47 million in Kanto (Japan).

To address this issue, the OECD has classified regions within each country based on two territorial levels. The higher level (Territorial Level 2) consists of 578 large regions and the lower level (Territorial Level 3) is composed of 1 793 small regions, including the accession and enhanced enlargement countries. This classification (which, for European Union countries, is largely consistent with the Eurostat NUTS classification) facilitates comparability of regions at the same territorial level.

All the data shown here refer to small regions with the exception of Brazil, Chile, China, India, Russian Federation and South Africa.

In addition, the OECD has established a typology according to which regions have been classified as predominantly urban, predominantly rural and intermediate, based on the percentage of regional population living in rural communities.

Sources

• OECD (2009), OECD Regions at a Glance 2009, OECD, Paris.

Further information

Analytical publications

• OECD (2006), OECD Territorial Reviews - Competitive Cities in the Global Economy, OECD, Paris.
• OECD (2006), The New Rural Paradigm: Policies and Governance, OECD, Paris.
• OECD (2008), OECD Territorial Reviews, OECD, Paris.
• Spiezia, V. (2003), “Measuring Regional Economies”, OECD Statistics Brief, No. 6, October, OECD, Paris, www.oecd.org/std/statisticsbrief.

Statistical publications

• OECD (2009), Labour Force Statistics, OECD, Paris.

Online databases

• OECD Regional Database.

Web sites

• OECD eXplorer, www.oecd.org/gov/regionaldevelopment.
• Territorial grids, www.oecd.org/gov/regional/statisticsindicators.