The definition of peripheral areas the term of periphery is linked with economic perspective of centre and periphery as two opposite poles. This relationship is based on the social inequity and unfair distribution of political power. This polarization can be seen in many European countries that in recent years experienced tension between regions in terms of a polarization between dynamic and growing metropolitan areas and rural regions with shrinkage and decline and increasing inequalities between rich and poor neighbourhoods (Kühn 2014).

Historically urban and rural areas were perceived with binary and contradictory logic (Painter 2007). Core-periphery development models were made during the 20th century to describe uneven economic relations between different regions. These economic models and theories were based on the Keynesianism and aimed to explain the market imbalances (Blažek and Uhlíř 2011).

Crucial distinguishion was made by Friedmann (1973) who named these regions as a core and a periphery. He describes core regions as the centres of prosperity, technological, economic and social innovations and management, concentration of population and more autonomous regions than peripheries. Cores and peripheries constitute a spatial system centred on the poles of intense innovation and weak innovation. The core is a centre of power and dominance and prestige (Rogers, Castree and Kitchin 2013). Peripheries are subordinated to cores and suffer from power and innovation imbalance. 

Friedmann (1973) also identified different relations between core and periphery:

•  Domination effect – The centre continuously weakens the periphery by transferring the capital, natural and social resources from periphery. It creates a dominance of centre based on unfair relations when periphery is subordinated to the centre as it can be used for explaining the colonial pattern of transformation.

• Information effect – There is a better potential for interaction within the centre due to higher concentration of people, production and demand. Due to concentration there is an easier exchange of information between different actors. Higher income and capital in the centre makes the implementation of decisions easier.
• Psychological effects – because of higher concentration of there is higher density of interaction in the centres. Opportunities are more visible and better implemented because of positive expectation of other innovations.
• Modernization effects – social values and behaviour, and institutions are more flexible in the core. That leads to better acceptance of innovations.
• Coupling effects – innovations tend to create another innovation and affect also related sectors because of sharing the same infrastructure and subcontractors.  There is also a demand for new services and products.  
• Production effects – because of higher concentration the prices in the centre are reduced. New structure of economic relationships is formed in the centres, where specialization of the production or temporary utilizing monopoly position is needed.

These theories were extended by the concept of growth poles and growth centres and were used also on the global scale. Another factors as transport cost or economic structural change and technological innovations or communication technology had to be taken into account (Kühn 2014). Recently the term of knowledge economy has emerged with focus on concentration of knowledge services in the centres. Position of centres is supported by location of knowledge and qualified institutions, universities, business services (Crone 2012). This knowledge than attracts qualified and educated people to metropolises and put a pressure on peripheries in the terms of insufficient social capital. Even though these theories have been criticized for their black and white character, they represent an important economical approach for regional development.

What Kühn (2014) considers as an essential is that peripherality should be perceived as a multidimensional concept that intercorporate different processes with different intensity in the economical, sociological and political dimensions as it was mentioned before. Different processes connected with centralization and peripheralization can be identified within all dimensions as they are mentioned in figure 8. Sociologically peripheralization is about spatial disadvantages and micro-scale neighbourhoods struggling with disadvantages and poverty. From the political point of view uneven distribution of power is a crucial element.

Kühn (2014) does not offer any solution, but more an introduction to the actual problems of peripheries and their position towards the central areas. He sees the tendencies to support centralization by promoting metropolises without consideration of what is happening in the peripheral areas. He suggests that this phenomenon has a potential for future exploration since it is a relevant perspective for studying tensions and relations between different regions. He sees the opportunity in the polycentric and balanced spatial development suggested by EU’s Territorrial Agenda 2020 that aims on smart and sustainable development of EU regions in the place-based perspective. Otherwise the trend of metropolization will weaken and unsecure successful development in peripheral areas.