Reference metadata describe statistical concepts and methodologies used for the collection and generation of data. They provide information on data quality and, since they are strongly content-oriented, assist users in interpreting the data. Reference metadata, unlike structural metadata, can be decoupled from the data.
[ES1] National Institute for Statistics (INE) (Spain)
1.2. Contact organisation unit
SG for Social Statistics
1.3. Contact name
Confidential because of GDPR
1.4. Contact person function
Confidential because of GDPR
1.5. Contact mail address
1.6. Contact email address
Confidential because of GDPR
1.7. Contact phone number
Confidential because of GDPR
1.8. Contact fax number
Confidential because of GDPR
2.1. Metadata last certified
12 March 2026
2.2. Metadata last posted
12 March 2026
2.3. Metadata last update
12 March 2026
3.1. Data description
The Urban Audit Project, named as data collection for sub-national statistics (mainly cities), is based on a collection of data, providing information and comparable measurements on the different aspects of the quality of urban life in cities.
The projects' ultimate goal is to contribute towards the improvement of the quality of urban life: it supports the exchange of experience among European cities; it helps to identify best practices; it facilitates benchmarking at the European level and provides information on the dynamics within the cities and with their surroundings.
Directed by the European Commission Directorate-General for Regional and Urban Policy via Eurostat and developed by the National Statistics Institutes of the Member States, its main purpose is the collection, estimation and publishing of socio-economic statistical data in order to know and measure the quality of life in a specific amount of territories.
The Urban Audit Project requires that the INE collects and supplies Eurostat with a wide range of variables regarding the economic, demographic and social situation of most Spanish medium and large-sized cities (municipalities). The Urban Audit collection currently contains 144 variables and a huge number of indicators. These indicators are derived from the variables collected by the European Statistical System. Nevertheless, dissemination via the INE website is restricted to a selection of 40 indicators.
3.2. Classification system
Due to the fact that it is a study that collects information from several social and economic dominions, the classification systems are those corresponding to the numerous surveys and statistics used as sources of information. The following national classifications are used among others: National Classification of Economic Activities CNAE-2009, National Classification of Occupations NCO-11 and International Standard Classification of Education ISCED-2011.
Regarding territorial units, they are all encoded according to a series of criteria established by Eurostat and the European Commission Directorate-General for Regional and Urban Policy.
3.3. Coverage - sector
Indicators and variables cover several aspects of the quality of life, such as Demography, Social Aspects, Economic Aspects, Education and Training, Environment, Travel and Transport and Culture and Recreation.
3.4. Statistical concepts and definitions
For most variables the definitons of the City statistics manual have been followed. The coherence and compliance of our methodologies with the glossary is rather good. Obviously in all cases that is required to apply an estimation method, there is not a standard way to follow, but we assure that the results obtained are quite reliable and coherent with those we would expect.
3.5. Statistical unit
Since the information is collected from different registers, censuses and social and economic surveys, the statistical unit is applicable to each one of these statistics.
3.6. Statistical population
As the information is collected from different registers, censuses and social and economic surveys, it is not applicable to a single statistical population. The statistical population corresponds to these registers, censuses and surveys used as sources of information. The indicators refer to the statistical population established in each one of the statistics and surveys. Nevertheless, It may be stated that for most of the variables, the objective statistical universe are the regular residents of a specific geographical area.
3.7. Reference area
For Spain, information is collected in the following scopes:
At City level, with 112 cities.
At FUA level, with 68 areas.
3.8. Coverage - Time
Time coverage is 1990-2023. Check details in section 5 regarding the reference period.
3.9. Base period
The data has the base period of the surveys and statistics that serve as a source of information.
The unit of measurement varies from indicator to indicator; from variable to variable. For most indicators and variables the unit of measure is number of persons or percentage.
2023 and 2024 are the reference years for the main data collection. It exits information of all the years after 2001, as well as for 1996 and 1991, that were the reference of the compilation denominated "historical". However, the publication on the INE website will only present information from 2010 onwards. The reference periods 2023 and 2024 are part of the current round of data collection.
6.1. Institutional Mandate - legal acts and other agreements
All supply of urban statistics data is based on a volunteer agreement, since there is no community legislation on this matter. The Urban Audit Project (former name) has been in operation for over 15 years, and despite the fact that it still does not have its own regulation, it constitutes a consolidated task between European regional and urban statistics. Nevertheless, works are being performed to carry out a proposal that allows the availability of a legal base for specific territorial classifications and typologies, some of which are part of the Urban Audit.
6.2. Institutional Mandate - data sharing
Not applicable.
7.1. Confidentiality - policy
Regulation (EC) No 223/2009 on European statistics (recital 24 and Article 20(4)) of 11 March 2009 (OJ L 87, p. 164), stipulates the need to establish common principles and guidelines ensuring the confidentiality of data used for the production of European statistics and the access to those confidential data with due account for technical developments and the requirements of users in a democratic society.
7.2. Confidentiality - data treatment
Not applicable.
8.1. Release calendar
There is no fixed release calendar.
Data are released as soon as they are received and validated.
The data is updated when available. The database is updated accordingly depending on the data availability of new and revised data.
10.1. Dissemination format - News release
The results of statistical operations are generally disseminated through press releases, which can be consulted both in the menu corresponding to each statistical operation and in the Press Releases section.
Spain´s data is available in Eurostat's City Statistics database online at the following website: Eurostat category.
The database is organised in two sections:
Cities and greater cities;
Functional urban areas.
To display data for the Italian spatial units, it is possible to filter the code by writing "IT" in the "geopolitical entity" window.
The national publication is also available on the website of the Spanish National Statistical Institute (INE): Urban Indicators.
10.4. Dissemination format - microdata access
Not available.
10.5. Dissemination format - other
Not available.
10.6. Documentation on methodology
The definitions of the City statistics manual have been followed for most variables. Additional information on methods applied and the deviating methodology used in the collection are provided in the Annexes.
The methodology of the national publication is also available on the website of the Spanish National Statistical Institute (INE): National methodology.
The procedures for ensuring high data quality are explained in the City statistics manual.
11.1. Quality assurance
Ensuring the quality of the Urban Audit is a comprehensive process. Three main validation controls are performed regularly: univariate, multivariate and detection of irregular values.
To ensure a high quality of the data, certain validation procedures that already exist have been analysed and adapted to the latest standards. A complete set of validation rules has been developed.
11.2. Quality management - assessment
The collection of "Urban Audit" data provides information and comparable measurements on the different aspects of the quality of urban life in European cities. The indicators selected to be published on the INE website are among the most relevant, and many of them are disseminated via the main websites and publications of the EU.
The main appeal is based on providing information at municipal and supramunicipal levels for most of the socio-economic scopes in said territories. Many of those indicators come from variables that have been object of estimation, which adds value to the Project since few or no surveys include information for such geographical levels.
The Population Census is one of the main sources of information. Many other information comes from administrative registers, which decreases the burden and cost. The main inconvenience appears in the inter-census years since the availability of data decreases.
Some data have limitations that are inherent to sampling statistical operations, such as non-response and sampling errors or variation coefficients of the estimates.
The information is not only subjected to an internal validation but is also object of a strict validation check by Eurostat in order to detect inconsistencies or errors.
12.1. Relevance - User Needs
Users' needs and the requirements of the interested party are compiled in several forums (Work groups, Conferences, meetings with administrative bodies, etc). In general, it may be said that the 2 main users are Eurostat and the European Commission Directorate-General for Regional and Urban Policy. OECD and other EU bodies also make a substantial use of the Project data. Each country, however, has its own set of users. In Spain, the dissemination of the Project has been very scarce and there is only certainty of a few users in city councils and/or universities.
One of the main needs of the Project that was not fulfilled in the past was the availability of updated information. This problem has been corrected with the insertion of annual cycles of data collection.
12.2. Relevance - User Satisfaction
The users' reactions (opinions and suggestions) are collected in several forums. The main needs of the Project are defined by the European Commission Directorate-General for Regional and Urban Policy, in collaboration with Eurostat, in order to obtain the largest possible base of information for the cohesion policy in the EU.
Through the urban and regional Work Groups NUAC and RESCO, respectively, it has been possible to know the availability of information from a supply perspective, and to a lower extent, the need of information from the demand point of view. At the same time, the two large aforementioned organisations and others such as OECD have held meetings regarding regional and urban matters.
The Standing Committee of Regional and Urban Statistics (SCORUS) is among one of the many forums in which experiences are exchanged.
12.3. Completeness
The Urban Audit Project has been in operation for over 15 years, and despite the fact that it still does not have its own Regulation, it is a consolidated task between European regional and urban statistics. In order to address the problem and attain a larger amount of information, the European Commission grants aids that are formalised by means of an Agreement on Subsidies. The INE has been committed to these agreements during the last cycles of data collection. This formalisation implies the supply of the maximum amount of information available for all the required variables, for all the established spacial units and for all the required reference years.
Eurostat aims at attaining 80% of the required information. In general, the INE, has exceeded said level in the last data collection cycles, though it is a general aim, since the availability of data differs according to the dominion, the territorial level and the reference period.
13.1. Accuracy - overall
Since it is a publication that is obtained from several statistical sources, in some cases the latter may be affected by various errors. The main guarantee in the accuracy of the provided information is the existence of expert groups with a thorough knowledge of the different statistical sources and their problems as well as their interrelations. These groups adjust to the regulations and different methodologies and work to obtain reliable data.
13.2. Sampling error
Given the diversity of sources which provide this research with data, it is difficult to assess the sampling and non-sampling errors it is affected by.
13.3. Non-sampling error
Given the diversity of sources which provide this research with data, it is difficult to assess the sampling and non-sampling errors it is affected by
14.1. Timeliness
In general, the time elapsed between the reference date of the data and the publication of the results is approximately 24 months.
14.2. Punctuality
The Agreement on Subsidies that is formalised for the collection of data in each cycle is 36 months. There is no legal period to provide the data during that time, nevertheless, the INE sends partial information to Eurostat as soon as it has information that is considered to be complete enough (for a specific year or for a complete geographical level or for a particular variable or group of them belonging to a dominion as a whole, etc). Delays, which are understood as exceeding the 36 months, are infrequent and are usually consequence of detecting an update or modification in the source data (which implies having to review the information that has already been sent) or due to inserting "last minute" methodological or territorial changes.
Nevertheless, the indicators selected for this publication do not have a publication calendar on a specific date. The objective, nevertheless, is to carry out an annual update.
15.1. Comparability - geographical
From the published data point of view, the geographical comparability depends on the territorial level:
At municipal level, the results of the information that is directly available are perfectly comparable due to the fact that the procedure is the same. If the information requires an estimation, the method used is understood to produce comparable results for a specific geographical level. Comparability is also performed in the supramunicipal and conurbation levels. At sub-municipal level, comparability shall be performed between the different districts or areas, within the municipality in question.
Nevertheless, data comparability among European territorial levels is limited and not always possible, sometimes due to the drifting of definitions, the use of different data sources and application of estimation methods that are completely different. In any case, to avoid erroneous comparisons, the information on data sources and the statistical base is always explained in the set of data.
15.2. Comparability - over time
The continuity of the methodology applied since the beginning of the fifth data collection cycle of the Urban Audit Project allows better comparability over time since 2010, ie in most cases the data are comparable in time because it has been used The same source in order to preserve a chronological series throughout the collection. In a few variables, the breaks in the time series are conveniently explained. Some domains where the methodology has not been modified over time are demography, nationality, employment by activity categories, education or tourism.
It has been taken 2010 as the starting year for the publication of indicators in the INE website, allowing the creation of a time series in most of them. During the years prior to that date, the Project did not have enough stability, as there were frequent methodological breaks. Therefore, it was not considered convenient to provide information.
15.3. Coherence - cross domain
We can state that the coherence and compliance of our methodologies with the glossary definitions are generally satisfactory. In cases where estimation methods must be applied, there is not always a single standard approach to follow. However, we ensure that the results obtained are reliable and consistent with the expected values.
The coherence of the information contained in the transmitted data is ensured through the consistency of the statistics and surveys used as the basis for the different indicators.
The 2011 Census provides substantial information but also poses certain time-related limitations, particularly for demographic indicators. For these indicators, the Municipal Register as of 1 January 2011 has been used as the main source in order to ensure consistency with the rest of the intercensal years, whose source is also the Municipal Register.
The use of results derived from different statistical sources does not imply a coherence problem, but rather reflects differences in the measurement of the variable or indicator.
15.4. Coherence - internal
The information contained in the published indicators has complete internal coherence, since the base information coming from statistics and surveys is validated by the production units.
The estimates, for example in the main labour market indicators, have enough internal coherence since they are based on the same set of microdata and are calculated using the same estimation methods. When grouping at provincial level the estimations obtained regarding "economically active persons", the results are similar to those of the figures of economically active persons of the EAPS (Economically Active Population Survey), in which the bigger the group means the better the approximation. The municipal estimations grouped by provinces of the "unemployed persons", coincide with the unemployment figures of the EAPS.
Although the Eurostat methodology refers to population over 15 years of age for certain labour market variables, the indicators of the publication have included population over 16 years of age in order to maintain coherence with the EAPS, since it has been the main source of reference in the performed estimations.
This publication constitutes an extract of the Urban Audit Project, which is carried out by the Deputy Directorate-General for Social Statistics of the Spanish National Statistical Institute (INE). The project as a whole is covered by the Grant Agreement offered by Eurostat to the participating countries. For the current data collection cycle entitled "Data collection for sub-national statistics (mainly cities)", the total estimated cost for Spain amounts to EUR 422,276.24, with a maximum grant from the European Commission of EUR 295,593.37. This action has a duration of 36 months and started on 1 May 2024.
In addition to the aforementioned grant, at national level the estimated budget allocation amounts to EUR 120.98 thousand in the Annual Programme 2025 of the National Statistical Plan 2025–2028.
There is no burden on respondents, since the underlying information is obtained from surveys and statistics that have already been published.
17.1. Data revision - policy
Preliminary data is not published.
17.2. Data revision - practice
Since the collected information is very extensive, there may be errors in the data. The most detected errors are corrected continuously.
18.1. Source data
In most cases, the data has been obtained from the censuses, the different administrative and statistical registers as well as the national and local databases. Another important part of the work is obtained by applying different estimation methods.
For the information included in this publication, the main registers used are the following:
Municipal Register of Inhabitants.
Land Registry.
AEAT (Spanish Tax Administration Agency) via the INE-AEAT agreement, based on the ERGEO request.
SEPE (Spanish Public Employment Service).
Ministry of Education, Culture and Sport.
National Geographic Institute (IGN).
Notarial records.
The Population and Housing Censuses are the most relevant source of information used for the data whose collection is direct as well as for the estimation processes applied. In these processes, besides the Censuses and Municipal Register, the Economically Active Population Survey constitutes another one of the most important sources. Others surveys and statistics that serve as a source of data are the VS (Vital Statistics) and the Hotel Occupancy Survey. The CBR (Central Business Register) is another set of information used by some indicators.
18.2. Frequency of data collection
Data are collected annually, but many indicators are only available in census years.
18.3. Data collection
Data collection corresponds to the different surveys and statistics that serve as a source of information for the indicators. The Urban Audit team in the Subdirectorate collects all of that information and includes it in a database, which is the base for the compilation of indicators. There is a NUAC (National Urban Audit Coordinator) in each State participating in the Project. The NUAC is responsible for the information collection in the INE and is considered the coordinator by Eurostat.
The estimation processes are carried out by the same team, which generally use SAS to do so, and also the input of data coming from several sources, mainly the Population and Housing Censuses, the Municipal Register and the Economically Active Population Survey.
18.4. Data validation
Different verifications of data are performed before publishing:
Type of control: The data fields designed for the numbers can only accept the numbers.
Duration Date: The data fields contain an allowed data length. E.g. country code has two digits.
Presence control: Controls that all data fields are present.
Verification of Uniqueness: controls that specific fields do not have duplicated values.
List Verification Code: only defined variables and geographical codes are accepted.
Verifications of coherence: the values of the related variables must be consistent.
Range of control: The values must be within a defined range.
Verification of balance: The value sum of the subgroups must be the same as the total. Population, e.g.; total= male + female.
Control of the validation of spacial level: Comparison of geographical aggregates in the different levels. For example; the value for the urban functional area must be higher than the value for the city.
Validation time series: It detects an unusual evolution in time.
18.5. Data compilation
The National Statistics Offices collect the data. All the available statistical data (INE, municipal authorities, etc) are collected and sent to Eurostat. Unfortunately, not all information is directly available. Many variables have to be estimated or adjusted to the established definitions and this is the task that specifically constitutes the great added value of the Project. In the INE almost all surveys have a regional breakdown, at NUTS 2 or NUTS 3 level, but the municipal level is much more difficult to obtain. The Census, the population registers and the Economically Active Population Survey are some of the main sources on which the estimations are based.
The Urban Audit project requires that the INE supplies a wide range of indicators regarding the economic, demographic and social situations of the Spanish municipalities. This information shall be provided at highly broken down levels over an annual base, even though the frequency can be extended depending on the type of variable.
The need to carry out calculations in different aggregation levels is an essential factor in the determination of the estimation process, since there has to be a formal coherence in the figures at different aggregation levels. In this way, when calculating the value of a variable given for the city of Barcelona, this estimation has to be coherent with the estimation calculated for the FUA (Functional Urban Area) of Barcelona. For this reason, the methodological proposals that have been developed are based on the estimation of all Spanish municipalities, and subsequently the FUAs are calculated by means of the aggregation of the municipal figures.
In all cases, the calculation proposals combine the use of the administrative registers and the statistical techniques based on modelling. The following scenarios are distinguished: • The relevant variable is an administrative register in itself. • The relevant variable may be obtained by means of the direct estimation based on sampling data. • The relevant variable is available via the sampling information, but not at the breakdown level required for the Urban Audit project. Of the aforementioned cases, the most relevant is the third case. Sampling information is available at a greater level of aggregation and there is an administrative register that allows carrying out the necessary calculations.
For example, to estimate the Economically Active population based on the EAPS data, the sample is obtained classified by economically active persons, provinces, age and sex, and the data is quarterly. With this sample, the probability of being economically active depending on the age and province of residence is calculated for each quarter and sex. To do so, a Generalized linear mixed model is used for the binary response variable considering a random effect, the province. Once the probabilities are estimated for a quarter, they are applied to the population estimated for the demographic variables at municipal level by age and sex. To obtain the municipal Economically active persons, this population is multiplied by the probability of that same age, sex and province to which the municipality belongs. The economically active persons are obtained by calculating the average quarterly economically active persons for that year. When grouping at provincial level the estimations obtained, the results are similar to those of the figures of economically active persons of the EAPS, in which the bigger the group means the better the approximation.
18.6. Adjustment
No seasonal adjustments are made.
None.
The Urban Audit Project, named as data collection for sub-national statistics (mainly cities), is based on a collection of data, providing information and comparable measurements on the different aspects of the quality of urban life in cities.
The projects' ultimate goal is to contribute towards the improvement of the quality of urban life: it supports the exchange of experience among European cities; it helps to identify best practices; it facilitates benchmarking at the European level and provides information on the dynamics within the cities and with their surroundings.
Directed by the European Commission Directorate-General for Regional and Urban Policy via Eurostat and developed by the National Statistics Institutes of the Member States, its main purpose is the collection, estimation and publishing of socio-economic statistical data in order to know and measure the quality of life in a specific amount of territories.
The Urban Audit Project requires that the INE collects and supplies Eurostat with a wide range of variables regarding the economic, demographic and social situation of most Spanish medium and large-sized cities (municipalities). The Urban Audit collection currently contains 144 variables and a huge number of indicators. These indicators are derived from the variables collected by the European Statistical System. Nevertheless, dissemination via the INE website is restricted to a selection of 40 indicators.
12 March 2026
For most variables the definitons of the City statistics manual have been followed. The coherence and compliance of our methodologies with the glossary is rather good. Obviously in all cases that is required to apply an estimation method, there is not a standard way to follow, but we assure that the results obtained are quite reliable and coherent with those we would expect.
Since the information is collected from different registers, censuses and social and economic surveys, the statistical unit is applicable to each one of these statistics.
As the information is collected from different registers, censuses and social and economic surveys, it is not applicable to a single statistical population. The statistical population corresponds to these registers, censuses and surveys used as sources of information. The indicators refer to the statistical population established in each one of the statistics and surveys. Nevertheless, It may be stated that for most of the variables, the objective statistical universe are the regular residents of a specific geographical area.
For Spain, information is collected in the following scopes:
At City level, with 112 cities.
At FUA level, with 68 areas.
2023 and 2024 are the reference years for the main data collection. It exits information of all the years after 2001, as well as for 1996 and 1991, that were the reference of the compilation denominated "historical". However, the publication on the INE website will only present information from 2010 onwards. The reference periods 2023 and 2024 are part of the current round of data collection.
Since it is a publication that is obtained from several statistical sources, in some cases the latter may be affected by various errors. The main guarantee in the accuracy of the provided information is the existence of expert groups with a thorough knowledge of the different statistical sources and their problems as well as their interrelations. These groups adjust to the regulations and different methodologies and work to obtain reliable data.
The unit of measurement varies from indicator to indicator; from variable to variable. For most indicators and variables the unit of measure is number of persons or percentage.
The National Statistics Offices collect the data. All the available statistical data (INE, municipal authorities, etc) are collected and sent to Eurostat. Unfortunately, not all information is directly available. Many variables have to be estimated or adjusted to the established definitions and this is the task that specifically constitutes the great added value of the Project. In the INE almost all surveys have a regional breakdown, at NUTS 2 or NUTS 3 level, but the municipal level is much more difficult to obtain. The Census, the population registers and the Economically Active Population Survey are some of the main sources on which the estimations are based.
The Urban Audit project requires that the INE supplies a wide range of indicators regarding the economic, demographic and social situations of the Spanish municipalities. This information shall be provided at highly broken down levels over an annual base, even though the frequency can be extended depending on the type of variable.
The need to carry out calculations in different aggregation levels is an essential factor in the determination of the estimation process, since there has to be a formal coherence in the figures at different aggregation levels. In this way, when calculating the value of a variable given for the city of Barcelona, this estimation has to be coherent with the estimation calculated for the FUA (Functional Urban Area) of Barcelona. For this reason, the methodological proposals that have been developed are based on the estimation of all Spanish municipalities, and subsequently the FUAs are calculated by means of the aggregation of the municipal figures.
In all cases, the calculation proposals combine the use of the administrative registers and the statistical techniques based on modelling. The following scenarios are distinguished: • The relevant variable is an administrative register in itself. • The relevant variable may be obtained by means of the direct estimation based on sampling data. • The relevant variable is available via the sampling information, but not at the breakdown level required for the Urban Audit project. Of the aforementioned cases, the most relevant is the third case. Sampling information is available at a greater level of aggregation and there is an administrative register that allows carrying out the necessary calculations.
For example, to estimate the Economically Active population based on the EAPS data, the sample is obtained classified by economically active persons, provinces, age and sex, and the data is quarterly. With this sample, the probability of being economically active depending on the age and province of residence is calculated for each quarter and sex. To do so, a Generalized linear mixed model is used for the binary response variable considering a random effect, the province. Once the probabilities are estimated for a quarter, they are applied to the population estimated for the demographic variables at municipal level by age and sex. To obtain the municipal Economically active persons, this population is multiplied by the probability of that same age, sex and province to which the municipality belongs. The economically active persons are obtained by calculating the average quarterly economically active persons for that year. When grouping at provincial level the estimations obtained, the results are similar to those of the figures of economically active persons of the EAPS, in which the bigger the group means the better the approximation.
In most cases, the data has been obtained from the censuses, the different administrative and statistical registers as well as the national and local databases. Another important part of the work is obtained by applying different estimation methods.
For the information included in this publication, the main registers used are the following:
Municipal Register of Inhabitants.
Land Registry.
AEAT (Spanish Tax Administration Agency) via the INE-AEAT agreement, based on the ERGEO request.
SEPE (Spanish Public Employment Service).
Ministry of Education, Culture and Sport.
National Geographic Institute (IGN).
Notarial records.
The Population and Housing Censuses are the most relevant source of information used for the data whose collection is direct as well as for the estimation processes applied. In these processes, besides the Censuses and Municipal Register, the Economically Active Population Survey constitutes another one of the most important sources. Others surveys and statistics that serve as a source of data are the VS (Vital Statistics) and the Hotel Occupancy Survey. The CBR (Central Business Register) is another set of information used by some indicators.
The data is updated when available. The database is updated accordingly depending on the data availability of new and revised data.
In general, the time elapsed between the reference date of the data and the publication of the results is approximately 24 months.
From the published data point of view, the geographical comparability depends on the territorial level:
At municipal level, the results of the information that is directly available are perfectly comparable due to the fact that the procedure is the same. If the information requires an estimation, the method used is understood to produce comparable results for a specific geographical level. Comparability is also performed in the supramunicipal and conurbation levels. At sub-municipal level, comparability shall be performed between the different districts or areas, within the municipality in question.
Nevertheless, data comparability among European territorial levels is limited and not always possible, sometimes due to the drifting of definitions, the use of different data sources and application of estimation methods that are completely different. In any case, to avoid erroneous comparisons, the information on data sources and the statistical base is always explained in the set of data.
The continuity of the methodology applied since the beginning of the fifth data collection cycle of the Urban Audit Project allows better comparability over time since 2010, ie in most cases the data are comparable in time because it has been used The same source in order to preserve a chronological series throughout the collection. In a few variables, the breaks in the time series are conveniently explained. Some domains where the methodology has not been modified over time are demography, nationality, employment by activity categories, education or tourism.
It has been taken 2010 as the starting year for the publication of indicators in the INE website, allowing the creation of a time series in most of them. During the years prior to that date, the Project did not have enough stability, as there were frequent methodological breaks. Therefore, it was not considered convenient to provide information.
