17
This study uses the following regional definitions for classification purposes. A core region
is defined as a region with one or more urban areas with a population density greater than 500 people
per square kilometre. Such an urban area is called an urban agglomerate.11 The term, adjacent region,
refers to those regions, which border on core regions, and that have one or more urban areas with a
population density greater than 100 people, but less than 500 / km2. Finally, a periphery region is a
region bordering only on an adjacent region or another periphery region. Furthermore, a periphery
region can have one or more urban areas with a population density greater or less than 100 people per
square kilometre.
4.3.3 The Methodology for Classifying the Regions
The analysis in this section is based on the CAP model set out in equations (1) - (9). To begin
the analysis of the economic geography of the EU with the CAP model, this section identifies and
classifies the core, adjacent, and periphery regions within the individual EU Member states. Regional
classification is based on a region’s urban population density, which complies with the theoretical
criterion of large market demand. This analysis adopts the Eurostat definition for the size of an urban
agglomerate and uses it to classify the individual NUTS 2 regions of a country.
The urban agglomerate definition defines the minimum criterion for the population density
value of a core region. Once the core regions are identified, the urban population densities of the
remaining regions can be found. Any adjoining region or first-ring region around the core that does
not satisfy the primary definition must be an adjacent region. In terms of concentric-circle theory, an
adjacent region is called a first-order contiguity region.
A second-order contiguity region is a region in the second circle of regions around a core
region and is called a periphery region. The spatial geographic distance from the core region to
adjacent region (θCA) is less than that of the core region to the periphery region, (θCP). Therefore,
although the minimum urban density value identifies the element in the subset core region, all the
11 Eurostat definition.