Sources and Methodology

Overview of sources, research principles, data processing methodology and limitations used by the institute in preparing demographic analyses.

Research Principles

The research section of this website is based on publicly available demographic data, official statistical sources and expert analyses from Slovenian and international institutions. The aim of the institute is to present data clearly, transparently and without political interpretation or sensationalism.

The data are used to understand Slovenia’s long-term demographic trends: fertility, population ageing, natural increase, migration, municipal differences, regional development and population projections.

Each important chart or data point on the website should include a source so visitors can verify where the information comes from.

Main Data Sources

National sources

• Statistical Office of the Republic of Slovenia (SURS / SiStat)

• Institute of Macroeconomic Analysis and Development (IMAD)

• ZRC SAZU and other research institutions

• publicly available municipal and state institution data

International sources

• Eurostat and the EUROPOP2023 database

• comparative European demographic indicators

• other publicly available international statistical sources when needed for comparison between Slovenia and the European Union.

Data Processing Methodology

Data are presented through time series, comparative charts, municipal overviews and thematic analyses. Trends are shown across periods that help explain change over time, not only single-year values.

The research uses core demographic indicators: population size, live births, deaths, natural increase, immigration, emigration, net migration, total fertility rate and population age structure.

Population projections are treated as future development scenarios, not as final predictions. They depend on assumptions about fertility, mortality, migration and the age structure of the population.

Charts are prepared to make the data easier to understand and do not replace original statistical databases. Whenever possible, sources are listed next to charts or below individual research sections.

Data Limitations

Demographic data may later be updated, corrected or methodologically adjusted. Values may therefore differ slightly between different publications and institutions.

International comparisons must take into account different publication schedules, methodological adjustments and statistical classifications used by individual countries.

For projections, it is especially important to understand that they are not fixed forecasts, but calculations of possible future development under specific assumptions.

Transparency and Verification

The institute aims to make data verifiable, sources clearly visible and interpretation separated from numerical facts. This is especially important for sensitive topics such as fertility, population ageing, migration and regional development.

The goal of the website is not to replace official statistical institutions, but to make their data more accessible to the public, municipalities, media, researchers and everyone interested in Slovenia’s demographic future.

The research section may be expanded over time with new data, reports and thematic analyses.