Register-based Census

In 2021, the Statistical Office will conduct a census of population, households and dwellings. The reference date will be 1 January 2021. This will be the 19th population census in Slovenia and the fourth that will be register-based. Since not all sources for all census topics are availabe at the same time, the results will be published gradually. First, the data on the population will be published (end of April 2021), followed by the data on families and households (end of November 2021) and finally the data on dwellings (first half of 2022).

Censuses - once the most extensive statistical surveys

Population censuses, which are among the most extensive statistical surveys, are conducted by most of the countries in the world. Census data are truly a treasure. Censuses are a country’s identity card, a mirror that shows how many people there are, where they come from, how educated they are, how many of them are employed, and in what communities and dwellings they live.

For many countries population censuses are the only source of data on the number of population and important milestones for any country, since a comparison of results of successive censuses reveals the picture of population development through decades and centuries. Usually, population censuses are also conducted to collect data on households, families and dwellings. However, each country can also collect other nationally important data. Each country can also choose the way the data will be collected. Since 2011, Slovenia has no longer conducted a census in the field, but as linking different databases and registers.

What is a register-based census?

A registered-based census is a method of producing data on population, households and dwellings by statistically linking existing administrative and statistical data sources without using fieldwork enumeration. It can be said that the essence of a register-based census is to make from raw and unrelated data useful and high-quality statistics that reflect as much as possible the real situation.

Register-based census 2011 - an important milestone in the development of Slovene statistics

The first register-based census in Slovenia was conducted in 2011 as an important milestone in the development of Slovene statistics. With a register-based population census Slovenia in 2011 joined few European countries that had already conducted such censuses. Denmark was the first country in the world to conduct such a census already in 1970, while most of the other countries conducted such censuses for the first time in 2011. In 2021, the register-based census will also be conducted in Lithuania, Latvia, Spain and Turkey.

An important feature of the register-based census is also the possibility of more frequent derivation of data. This census method was in Slovenia implemented again in 2015 and 2018. Most of the themes about the population, which were once available only from a census (e.g. education, activity status), are from 2011 on available annually and users no longer have to wait ten years for these data.

The result of many years of development of Slovene statistics

The register-based census is the result of a long-term strategy to rationalize data collection by increasing the use of administrative data, the result of more than 40 years of development of Slovene statistics and registers. Following the example of the Scandinavian countries, already in the 1970s the Statistical Office set up some registers with unique identifier (PIN, address). These registers, which are today the backbone of the administrative system in the country (Central Population Register, Register of Spatial Units, Business Register of Slovenia), were built at the Statistical Office and in the 1990s turned over to be maintained by other institutions.

Data from the 1971 census were used to set up the Central Population Register with unique identifiers, which were in 1980 replaced by the citizen's PINs. These PINs were used for the first time in the 1981 census. In 1991 as well as in 2002 censuses, data on name, family name, address and PIN were already printed on the census questionnaires. The 1991 census was the last census with classical statistical data processing, when data were mostly edited manually. The 2002 census was already a so-called combined census – some data were collected in the field with paper questionnaires and some data were taken over from the registers. However, when in 2008 the Real Estate Register (REN) was established at the Surveying and Mapping Authority of the Republic of Slovenia, everything was prepared to conduct a register-based census in 2011.

The data from the census were therefore once used to set up the register and today the data from the register are used in the census. The circle is thus closed.

Gradual publication of data 

Not all sources for all census topics are available at the same time, so one of the characteristics of a register-based census is gradual publication of data. A sort of “mini census of the population” is in Slovenia conducted four times a year, when we publish data on all residents by age and sex to the lowest territorial unit. Data on population, age, sex and territory, which will be published at the end of April as of 1 January 2021, will be the first data of the "2021 census". When reported to international organizations (Eurostat and the UNECE), the data will be declared as census data. In 2021, EU Member States are obliged to conduct a census under Commission Regulation (EU) 2017/712. Data on households and families will be published in November 2021, and data on dwellings in the first half of 2022.

Since 2011, SURS has no special census website and all data with census topics are published regularly among different statistical themes (population, quality of life). Data from previous censuses are published on a special website of the 2011 census.

Advantages and disadvantages of the register-based method

Our experience with the last traditional field census in 2002 shows that the data from the register-based census are of better quality. Of course, we are aware of certain limitations of these data, as well as the fact that the data are slightly overestimated.

Many different sources

The register-based census process is possible only if enough quality sources are available. When conducting the register-based census in Slovenia, the following data sources are used:

• administrative registers (Central Population Register, Real Estate Register, Register of Spatial Units, Household Register)
• administrative registers and databases of various institutions: Employment Service of Slovenia, Ministry of Education, Science and Sport, Ministry of Labour, Family, Social Affairs and Equal Opportunities, Pension and Disability Insurance Institute, Health Insurance Institute of Slovenia, Tax Administration of the Republic of Slovenia, National Examination Center, chambers of commerce, crafts, entrepreneurship
• statistical register (Statistical Register of Employment)
• regular statistical surveys of the Statistical Office (Population, Migrations, Socio-economic characteristics of the population and migrants, Births, Students in tertiary education, Tertiary education graduates)
• 2002 Census of population, households and dwellings

Some data are for the same person available in several different sources. Such are e.g. data on the level of education achieved and the activity status.

What types of censuses will EU Member States conduct?

Ten EU Member States will conduct the 2021 census as a register-based census, the same number with a combination of field data collection and data from registers and databases, and six as a traditional field data collection. Many of countries that will conduct a traditional field census will modernize by using tablets, laptops, smartphones, internet.

How about countries on the territory of former Yugoslavia? Almost all of them (Bosnia and Herzegovina, Serbia, Montenegro, Croatia) will conduct the census in the traditional way, i.e. by collecting data in the field. The only exception is North Macedonia, which will use the combined census method.