Methodology

Subject of the Study, Its Spatial and Temporal Scope

The subject of the ‘Regional Profiles: Indicators of Development’ study is a comparative analysis of districts in Bulgaria. The comprehensive analysis covers the country’s entire territory and is based on information about the last sixteen years, for which there is available data on the indicators included in the study. Information for the analysis underlying the regional profiles comes from official statistics as well as data obtained in accordance with the Law for Access to Public Information (LAPI) by 30 June 2022. Any data published after this date has not been included in the analysis.

Information Sources

Information for compiling the ‘Regional Profiles: Indicators of Development’ study and its regular updates has been provided from two primary sources: official statistics and data obtained in accordance with the Law for Access to Public Information (LAPI).

The main source of official statistics is the national statistical system, more precisely, the National Statistical Institute (NSI). Additional data has been provided by the information systems of the National Social Security Institute (NSSI), the National Centre for Public Health and Analyses (NCPHA), The Ministry of Education and Science (MES), The National Revenue Agency (NRA), and others.

Methodological approach

The methodology is based on the following main principles:

1. The way of presenting the regional profiles is not by ranking districts but rather by grouping and analyzing specific clusters of districts.
2. A combination of one-dimensional complex metrics and multidimensional methods for regional comparison has been used. That makes it possible to overcome the drawbacks of both one-dimensional and complex metrics, while taking advantage of the strongpoints of multidimensional methods.
3. Neural networks, one of the most advanced methods for regional comparison, have been adopted for grouping and visualizing typical clusters of districts.
4. The selection of indicators and their organization into a system is based on four main groups of arguments: good practices, assessment potential, available information, and analysis of empirical data.
5. The terms, classifications, nomenclatures etc. used are officially and normatively approved.
6. Relative shares, ratios etc. are used instead of the absolute values of indicators to provide comparability between/among districts.
7. Indicators have been standardized to avoid the negative effects of scale, measuring systems etc.

Grouping of districts

Depending on the static analysis of indicators in each category, district performance has been assessed by means of a five-point scale: from ‘poor’ (the lowest degree) to ‘very good’ (the highest degree). Analysis is based on the last year’s available data (2022 or 2021).

Types of regional profiles

The methodological approaches in regional comparisons can be summarised in the following three basic types, depending on the use of:

• One-dimensional metrics,
• Complex metrics,
• Multidimensional methods (in particular, neural networks).

A combination of the three approaches has been adopted in this methodology; it allows, on the one hand, overcoming to a great extent the flaws of one-dimensional and complex metrics, and, on the other hand, taking advantage of the benefits of multidimensional methods.
All indicators are standardized by calculating the so called regional index.

For each group in the assessment system of indicators for the regional profiles, the so called complex indicator is calculated; it has the following characteristics:

• It provides comparability between districts, its values are calculated around the country average.
• Districts with positive values of the complex indicator are above the country average, and those with negative values – below it.
• The differences (ratios) between districts for each indicator have been preserved in the variance correction procedure, which ensures non-shifting values when calculating the complex indicator.

The final stage of the combined approach presents the summary result for all indicator groups and all districts in the form of visual clusters with the help of neural networks. In the present edition cluster formation is based on the primary indicator values.

System of indicators

The selection of indicators is based on their relevance to various aspects of the economic or social profile of the district as well as their interrelatedness and dynamics. A key argument for the choice of indicators is the availability, accessibility, and regularity of published information on the indicators or that of the primary data needed for their calculation. Two main sections result from this: Economic Development and Social Development. Each of the two includes 6 categories characterising the various aspects of the social and economic condition and the development of the districts.

For more information on the indicators choose one of the eight categories:

Each category contains a set of indicators that give a realistic picture of the state and development dynamics of districts in Bulgaria. The total number of indicators used in the methodology of the study is 68.