# Which population figures does Idescat publish?

As of 2021, the Population Census becomes annual, and this entails a change in the set of demographic statistical sources. The **annual Population Census** and the **six-monthly Population Estimates become the reference sources for the population at all territorial levels**, and the figures from the Municipal Population Register are the reference figures only in those cases in which the use of the registered population is expressly required according to the procedure protected by Law 7/1985, of 2 April 1985, regulating the local regime bases (LBRL) and the Regulation on population and territorial demarcation of local entities (RPDT).

Consequently, as of 2023 and in relation to the **Municipal Population Register**, Idescat will only disseminate the population figure by gender for **municipalities, counties and Aran, provinces, and the singular units of the Nomenclator**. Therefore, it does not disseminate the population by other territorial units (Catalonia, areas of the Territorial Plan, districts, and census tracts). The information by age, nationality and place of birth that was also offered by the Municipal Population Register before 2023 is no longer available for all territories, and this information is now obtained from the annual Population Census.

Therefore, the situation of the population sources is as follows:

### 1. Population Estimates

The Population Estimates are summary statistics whose objective is to determine at any given time the resident population in Catalonia, the provinces, the territorial areas and the counties and Aran. They also make it possible to calculate different demographic and socio-economic indicators of which the population is the denominator.

The Population Estimates offer a long and homogeneous series of the population by sex and age on 1 January and 1 July of each year since 1 January 1981. From 2021 onwards, the Population Estimates at 1 January of each year correspond to the data from the annual population census. Idescat also prepares the Advanced Population Estimates at 1 January and 1 July, with the aim of providing a population estimate with the minimum delay with respect to the reference date. The results remain in force until they are replaced each year by the final Population Estimates.

### 2. Population Census

The Population and Housing Census is the statistical operation that provides a count of the population resident in the territory and its geographical distribution. It also provides information on the main demographic and social characteristics of the population, households and families, and dwellings. The Census information allows for a very detailed territorial breakdown: Catalonia, provinces, territorial areas, counties and Aran, municipalities, census tract groups, districts and census tracts.

The Population and Housing Census 2021 has been conducted by combining administrative registers and the Population Register has been the basic element. Statistical procedures are applied in the Census so that they allow for a better count of the population and its characteristics than the Population Register. In addition, the system of producing demographic information based on administrative registers allows the Population Census to cease to be a decennial statistic and become an annual one from 2021 onwards. The annual Population Census is the source of data relating to the demographic structure (sex, age, place of birth and nationality) which until 2022 was offered annually from the Municipal Population Register. In addition to the structure variables, the annual Population Census offers information on migration, studies, and economic activity of the population.

### 3. Municipal Population Register

The Municipal Population Register is the administrative register where the inhabitants of a municipality are recorded and constitutes proof of residence. Each municipality is responsible for creating, managing, and maintaining its register. The population figures of the municipalities on 1 January of each year are approved by the Council of Ministers and are declared official by means of a royal decree published at the end of each year.

As of 2023, Idescat will only disseminate the population figures by sex for municipalities, counties and Aran, provinces, and the singular units of the Nomenclator. The figures from the Municipal Population Register are the reference figures in those cases in which the use of the registered population is expressly required in accordance with the procedure established by Law 7/1985, of 2 April 1985, regulating the local regime bases (LBRL) and the Regulation on population and territorial demarcation of local entities (RPDT).

### 4. Population Projections

The Population Projections constitute a forecast of the future evolution of the population and are calculated on a starting population, normally corresponding to the latest Population Census or Population Estimates, and with a set of hypotheses on the future evolution of birth rates, mortality, and migrations. The Population Projections are available for Catalonia, the provinces, the areas of the Territorial Plan, the counties and the municipalities, and are broken down by sex and age.

### 5. Seasonal Population Estimates

The Seasonal Population Estimates are an estimate of the population influxes borne by each municipality and measure the number of people in a municipality on an annual average and on a quarterly average. The calculation includes people who have some kind of link or relationship with the municipality, whether it be because they live, work, study in it, or because, without being their usual residence, they spend some period of time in it (holidays, summer holidays, weekends, etc.), either in their own residences or in the homes of relatives, friends or in tourist establishments (hotels, campsites, flats, etc.).