- 1.1Contact organisation
National Statistics Institute of Spain
- 1.5Contact mail address
Avenida de Manoteras 50-52 - 28050 Madrid
- 2.1Metadata last certified
06/03/2024
- 2.2Metadata last posted
11/03/2024
- 2.3Metadata last update
06/03/2024
- 3.1Data description
The objective of the Retail Trade Index is to provide information on the fundamental characteristics of the companies engaged in retail trade in Spain, which allow the evolution of the sector's activity to be measured over the short term.
This operation is framed within the scope of Regulation (EU) 2019/2152 of the European Parliament and of the Council of 27 November 2019 on European business statistics, repealing 10 legal acts in the field of business statistics.
This is a statistic with direct data collection. Results are presented as indices with the aim of measuring variations using the base year 2021 as a reference.
- 3.2Classification system
- Bienes de consumo
1 Alimentación
2 Resto
2.1 Equipo personal
2.2 Equipamiento del hogar
2.3 Otros bienes - Comunidades y Ciudades Autónomas
01 Andalucía
02 Aragón
03 Asturias, Principado de
04 Balears, Illes
05 Canarias
06 Cantabria
07 Castilla y León
08 Castilla - La Mancha
09 Cataluña
10 Comunitat Valenciana
11 Extremadura
12 Galicia
13 Madrid, Comunidad de
14 Murcia, Región de
15 Navarra, Comunidad Foral de
16 País Vasco
17 Rioja, La
18 Ceuta
19 Melilla - Tipo de comercio
1 Estaciones de servicio
2 Sin estaciones de servicio
2.1 Empresas unilocalizadas
2.2 Pequeñas cadenas
2.3 Grandes cadenas
2.4 Grandes Superficies
- Bienes de consumo
- 3.3Sector coverage
The RTI studies the population formed by companies whose main activity is registered in division 47 of section G (Trade) of the National Classification of Economic Activities (CNAE 2009).
- 3.4Statistical concepts and definitions
- Economic activity
The economic activity carried out by a company is defined as the creation of added value by means of the production of goods and services.
Each one of the statistical units (companies) studied frequently carries out various activities that should be classified in separate classes of the National Classification of Economic Activities. In general, the activities carried out by an economic unit may be of three types: main, secondary and auxiliary activities. The main activity differs from secondary activities in that it generates greater added value; whilst auxiliary activities are those that generate services that are not sold on the market and that only serve the unit on which they depend (administration departments, transport services or storage).
Due to the difficulties faced by companies in calculating added value when various activities are carried out, the activity which generates the greatest volume of business is considered the main activity or, failing that, that which employs the greatest number of persons. - Main economic activity code
The companies in the CCD present the encoded main activity according to the CNAE-2009 Classification. For the purposes of use, different levels are used, depending on the number of categories considered
- Economic activity
The economic activity carried out by a company is defined as the creation of added value through the production of goods and services.
The main economic activity is understood to be that which generates greatest added value. Facing the difficulty of calculated the added value for those companies that perform several activities, this considers the main activity to be that which generates the greatest turnover, or failing this, that which occupies the most employees.
The classification used in the National Classification of Economic Activities (CNAE-2009), prepared according to the conditions set out in the Regulation passing NACE Rev.2. This classification serves to determine who is carrying out the research.
In the case of research associations and companies whose main activity is the performance of R&D activities, mainly at the service of a given company or group of companies, units with CNAE 7211, 7219 or 7220; information is also requested on the main activity of those companies or groups of companies that benefit from their R&D activities, and their results will be computed within the branch of activity benefited by the research - Base year
The base year of an index indicates the period to which the comparisons of different situations carried out refer. This means that generally, a base year relatively close to the current period is usually chosen, given that comparisons lose meaning when the comparison periods become spread apart. For this reason, it is advisable to periodically update the information relating to the base year, in other words, to change the base year so that the index does not become obsolete and lose meaning.
- Turnover
This includes the total amounts invoiced by the observation unit, during the reference period, for the sales of goods and services supplied to third parties, considering both those carried out directly by the observation unit itself, and those from temporary outsourcing.
These sales of goods or services are accounted for in net terms, that is, including the charges to the client (transport, packages, etc.), though invoiced separately, but deducting the discount on sales for early payment, returns of sales or the value of returned packages, as well as taxes on sales. This includes taxes and fees on goods or services invoiced by the unit, but excludes the VAT paid by the client.
From an administrative point of view, the General Accounting Plan (PGC) (RD 1514/2007, of 16 November) defines the Total net value of turnover, using the following accounting items: C700+C701+C702+C703+C704+C705-C706-C708-C709 with:
C700. Sales of merchandise
C701. Sales of finished products
C702. Sales of semi-finished products
C703. Sales of sub-products and waste
C704. Sales of packages and packaging
C705. Provision of services
C706. Discount on sales for early payment
C708. Returns of sales and similar transactions
C709. "Taxes" on sales
Therefore, turnover includes neither subsidies nor other operating income. It also excludes financial and extraordinary income, and other income that affects the results of the fiscal year. - Specialised trade
That carried out by companies in which the turnover of a single type of product, considering as such those that are included in a single class of CNAE-2009, is greater than 50 percent, and is carried out by the companies that trade in fewer than five types of product, considering that their main activity is that corresponding to the product with the greatest turnover.
- Non-specialised trade
That trade which is carried out by companies that sell more than five types of product, considering as such those that are included in a single class of CNAE-2009, none of which has turnover exceeding 50 per cent of the total.
- Company
The company is the smallest combination of legal units that is an organizational unit producing goods or
services, which benefits from a certain degree of autonomy in decision-making, especially for the
allocation of its current resources. A company carries out one or more activities at one or more
locations. A company may be a sole legal unit. - Single retail stores
A Single retail store is considered to be that which carries out its commercial activity through a single premises.
- Service stations
Those companies whose main activity is the sale of fuel for automotion.
- Large chain store
A Large chain store is considered to be any company with 25 or more premises, and 50 or more employees.
- Department store
A department store is defined as any establishment that has a sales and exhibition area greater than or equal to 2500 metres square. Sales area is defined as any area that is accessible to the public and where sales transactions take place.
- Premises
Any structurally separated and independent building that is not dedicated exclusively to family housing, and in which economic activities dependent on a company are carried out, and in which one or more persons work for the company.
- Small chain store
A Small chain store is considered to be any company with more than one premises, except those with 25 or more premises and 50 or more employees.
- Personal ocupado
Se corresponde con el número total de personas que trabajan en la unidad de observación (incluidos los propietarios que trabajan, los socios que trabajan con regularidad en la unidad y los familiares no retribuidos que trabajan con regularidad en la unidad) y el de personas que, aunque trabajan fuera de la unidad, pertenecen a ella y son retribuidas por ella (por ejemplo, los representantes de comercio, el personal de mensajería y los equipos de reparación y mantenimiento que trabajan por cuenta de la unidad de observación). Incluye tanto al personal remunerado como al no remunerado.
- Economic activity
- 3.5Statistical unit
The basic statistical unit is the company that carries out any of the activities included in the population scope as the main economic activity.
The company is also the respondent unit, as it is perfectly defined and located, and having the accounting and employment data available facilitates the response and provides homogeneous information.
- 3.6Statistical population
The target population is made up of companies whose main activity is included within division 47 of the CNAE-2009 'Retail trade, except of motor vehicles and motorcycles'.
- 3.7Reference area
All statistical units located in the Spanish territory form the object of the research.
- 3.8Time coverage
In 2024, the publication of RTIs using base 2021 began.
Some of the main series that can be consulted are:
- Original series of national turnover indices at current prices and at constant prices of:
- General Index without Service Stations and Large-Scale Retail Index since January 2000.
- General Retail Trade Index and Service Stations Index since January 2000.
- Indices according to modes of distribution (large chain stores, small chain stores and single retail stores) since January 2005.
The series similar to the previous ones but corrected for calendar effects and corrected for seasonal and calendar effects can be consulted from the same date as the original series.
- Original series of turnover indices by Autonomous Communities and Cities of:
- General Retail Trade Index at current prices and at constant prices since January 2005.
- General Index without Service Stations at current prices since January 2001 and at constant prices since January 2003.
- Employment series of:
- General Retail Trade Index, General Index without Service Stations, Service Station Index and National Large-Scale Retail Index since January 2004.
- National indices according to modes of distribution (large chain stores, small chain stores and single retail stores) since January 2005.
- General Index without Service Stations of Autonomous Communities and Cities since January 2004.
- General Retail Trade Index of Autonomous Communities and Cities since January 2005.
- 3.9Base period
In 2024, the indices begin to be published using the new base 2021, in order to comply with the requirements established in Eurostat's Regulation (EU) 2019/2152 of the European Parliament and of the Council of 27 November 2019 on European business statistics, repealing 10 legal acts in the field of business statistics.
The RTI uses chain-linked indices so that:
- Base period is the year in which the mean of the year's indices is equal to 100. The base period is 2021.
- Reference period of the variable is the period whose values are compared with the variables (turnover and employed persons) of the reference month. The reference period for 2024 is December 2023.
- Reference period of the weightings is the period to which the weightings that serve as the system's structure refer. The reference period of the weightings for the year 2024 is December 2023.
- 4.1Unit of measure
The unit of measure is the indices and their rates of variation (monthly, annual and year-to-date average).
- 5.1Reference period
The turnover reference period is the calendar month.
The employment reference period is the employed persons on the last day of the month.
Data referred to the period: Mensual A: 2024 MES: 01
- 6.1Legal acts and other agreements
The compilation and dissemination of the data are governed by the Statistical Law No. 12/1989 "Public Statistical Function" of May 9, 1989, and Law No. 4/1990 of June 29 on “National Budget of State for the year 1990" amended by Law No. 13/1996 "Fiscal, administrative and social measures" of December 30, 1996, makes compulsory all statistics included in the National Statistics Plan. The National Statistical Plan 2009-2012 was approved by the Royal Decree 1663/2008. It contains the statistics that must be developed in the four year period by the State General Administration's services or any other entity dependent on it. All statistics included in the National Statistics Plan are statistics for state purposes and are obligatory. The National Statistics Plan 2021-2024, approved by Royal Decree 1110/2020, of 15 December, is the Plan currently implemented. This statistical operation has governmental purposes, and it is included in the National Statistics Plan 2021-2024. (Statistics of the State Administration).
This operation is intended to comply with Regulation (UE) 2019/2152 of the European Parliament and of the Council of 27 November 2019 on European business statistics, repealing 10 legal acts in the field of business statistics.
The aim of these Regulations is to regulate all business statistics in a single way, achieving greater rationalization and regulatory flexibility.
.
- 6.2Data sharing
The exchanges of information needed to elaborate statistics between the INE and the rest of the State statistical offices (Ministerial Departments, independent bodies and administrative bodies depending on the State General Administration), or between these offices and the Autonomic statistical offices, are regulated in the LFEP (Law of the Public Statistic Function). This law also regulates the mechanisms of statistical coordination, and concludes cooperation agreements between the different offices when necessary.
Through the collaboration agreements signed with the regional Statistics Institutes, a monthly exchange of information takes place, complying with the established requirements to preserve statistical confidentiality.
- 7.1Confidentiality - policy
The Statistical Law No. 12/1989 specifies that the INE cannot publish, or make otherwise available, individual data or statistics that would enable the identification of data for any individual person or entity. Regulation (EC) No 223/2009 on European statistics 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
- 7.2Confidentiality - data treatment
INE provides information on the protection of confidentiality at all stages of the statistical process: INE questionnaires for the operations in the national statistical plan include a legal clause protecting data under statistical confidentiality. Notices prior to data collection announcing a statistical operation notify respondents that data are subject to statistical confidentiality at all stages. For data processing, INE employees have available the INE data protection handbook, which specifies the steps that should be taken at each stage of processing to ensure reporting units' individual data are protected. The microdata files provided to users are anonymised.
All statistical personnel have the obligation to preserve statistical confidentiality (art. 17.1 of the Law on the Public Statistics Function - LFEP). In the specific case of this survey, only aggregated information is published.
- 8.1Release calendar
The advance release calendar that shows the precise release dates for the coming year is disseminated in the last quarter of each year.
- 8.2Release calendar access
The calendar is disseminated on the INEs Internet website (Publications Calendar)
- 8.3User access
The data are released simultaneously according to the advance release calendar to all interested parties by issuing the press release. At the same time, the data are posted on the INE's Internet website (www.ine.es/en) almost immediately after the press release is issued. Also some predefined tailor-made requests are sent to registered users. Some users could receive partial information under embargo as it is publicly described in the European Statistics Code of Practice
- 9.1Frequency of dissemination
Monthly
- 10.1News release
The results of the statistical operations are normally disseminated by using press releases that can be accessed via both the corresponding menu and the Press Releases Section in the web
- 10.2Publications
All information related to this index is published on the INE website. The following publications can be found on the websit:
- Press release, which highlights the components that most influence the indicator's evolution in the reference month, both in terms of sales and employment.
- Tables annex, containing the tables attached to the press release.
- Methodology, where you can consult the standardised methodological report, the statistical operations inventory sheet and the Retail Trade Index methodology.
- Related links where you can consult the results of previous bases (1994, 2001, 2005, 2010 and 2015).
All these publications can be consulted at the following link.
- 10.3On-line database
INEbase is the system the INE uses to store statistical information on the Internet. It contains all the information the INE produces in electronic formats. The primary organisation of the information follows the theme-based classification of the Inventory of Statistical Operations of the State General Administration . The basic unit of INEbase is the statistical operation, defined as the set of activities that lead to obtaining statistical results on a determined sector or subject based on the individually collected data. Also included in the scope of this definition are synthesis preparation.
Within the Retail Trade Index, indices and different rates of variation of sales and employment can be found for different levels of disaggregation by group, mode of distribution and geography. A distinction is made between index series of sales at current prices, at constant prices, adjusted for calendar effects and corrected for seasonal and calendar effects, as well as employment series. In addition to these series, the following link shows the weightings used in the calculation of the aggregate indices.
During 2023, the number of accesses to the INE website for consulting the tables containing information related to the Retail Trade Index statistical operation were:
AC1= 1,156,029 acceses
And the number of accesses for consulting metadata have been:
AC2= 2,131 acceses
- 10.4Micro-data access
A lot of statistical operations disseminate public domain anonymized files, available free of charge for downloading in the INE website Microdata Section
In the case of the Retail Trade Index, an anonymous microdata file is not published, these are only provided to the Regional Statistics Institutes with which a collaboration agreement has been signed for the submission of said information, by virtue of the collaborative Framework Agreement between the INE and the Central Statistics Offices of the Autonomous Communities (OCECAS).
- 10.5Other
It is possible to request tailored information from INE's Information area. Limitations on confidentiality or accuracy are taken into account when processing such requests.
- 10.6Documentation on methodology
Documentation with the methodology can be consulted at the following link.
The rate of completeness of metadata" is the ratio of the number of metadata elements provided to the total number of metadata elements applicable.
Metadata completeness rate, AC3=100% as all fields of the methodological file are filled in.
- 10.7Quality documentation
The statistics are processed in accordance with the EU guidelines, complying with the Code of Practice implemented by Eurostat.
Sections 10.6 to 17.2 of this document are the user-oriented quality report for this operation.
Furthermore, whenever Eurostat requests any kind of additional information they are supplied as soon as possible.
- 11.1Quality assurance
Quality assurance framework for the INE statistics is based on the ESSCoP, the European Statistics Code of Practice made by EUROSTAT. The ESSCoP is made up of 16 principles, gathered in three areas: Institutional Environment, Processes and Products. Each principle is associated with some indicators which make possible to measure it. In order to evaluate quality, EUROSTAT provides different tools: the indicators mentioned above, Self-assessment based on the DESAP model, peer review, user satisfaction surveys and other proceedings for evaluation.
The RTI production process is designed to guarantee the quality of the information used, as well as that of the results obtained from it. For this, different quality controls have been designed in all phases of the process, such as the detection of invalid values, estimation of non-response, supervision and inspection of fieldwork and other permanent controls on the flow of information.
This statistical operation is carried out in accordance with Regulation N (EU) 2019/2152 of the European Parliament and of the Council of 27 November 2019 on European business statistics, repealing 10 legal acts in the field of business statistics; and follows EU guidelines, complying with the Code of Practice and taking the necessary measures to ensure that the published indicator meets all the necessary quality requirements.
- 11.2Quality assessment
The RTI is a high quality product. Its sample size offers information up to the Regional level within reasonable sampling errors, the harmonised methodology used allows comparisons to be offered at the international level with a high level of solvency and gives an extremely valuable measure on the retail sector, which no other statistical source provides with the same level of detail.
As far as the limitations of the survey are concerned, it is necessary to point out those inherent to statistical operations by sampling, such as non-response and the aforementioned sampling errors or coefficients of variation of the estimates. In both cases, they remain within a reasonable limit.
The quality criteria listed in Article 12(1) of Regulation (EC) No 223/2009 of the European Parliament and Council, namely relevance, accuracy, timeliness, punctuality, accessibility, clarity, comparability and coherence, shall also be met.
- 12.1User needs
The RTI covers the statistical information needs of different user groups:
- Ministries and other public agencies
- Territorial administrations (Autonomous Communities and Cities, Provincial Councils, City Councils)
- Researchers and academic world
- Companies and non-profit institutions (research services of companies, foundations, associations, etc.), trade unions and employers' organisations
- Press and specialised media
- Individuals
The survey also responds to the needs of foreign users, both institutional and private. The former include Eurostat, OECD, IMF, United Nations, etc.
Some specific examples of the uses to which our information is destined are:
- The European aggregate calculation of RTI in Eurostat.
- The use of RTI in Spanish National Accounts for the calculation of GDP.
- Companies use it to know the evolution of the sector and their relative position within it.
- 12.2User satisfaction
The INE has carried out general user satisfaction surveys in 2007, 2010, 2013, 2016 and 2019 and it plans to continue doing so every three years. The purpose of these surveys is to find out what users think about the quality of the information of the INE statistics and the extent to which their needs of information are covered. In addition, additional surveys are carried out in order to acknowledge better other fields such as dissemination of the information, quality of some publications...
On the INE website, in its section Methods and Projects / Quality and Code of Practice / INE quality management / User surveys are available surveys conducted to date.(Click next link)
Those responsible for the survey are in permanent contact with the main users, in order to meet any specific need for information.
Furthermore, in view of the possibility that there may be requests that have not been met due to their complexity, these are evaluated at each base change, as well as any suggestions made by the main users. Most of these demands have been satisfied.
- 12.3Completeness
The survey responds to all information requirements, both national and international.
The RTI is governed by Regulation (EU) 2019/2152 of the European Parliament and of the Council of 27 November 2019 on European business statistics, repealing 10 legal acts in the field of business statistics. The requirements contained in each of them are satisfied by this indicator.
The "Rate of available statistics", R1, is the ratio of the amount of data produced in the statistical operation subject to a regulation, to the total amount of data required by that regulation.
Rate of available statistical results R1=100%
- 13.1Overall accuracy
The sample design attempts to minimise sampling errors and the different survey processes are aimed at eliminating or reducing, as far as possible, survey errors, both in the collection phase (monitoring the response rate and controlling the filtering of errors) and in subsequent imputing of non-response and calculation of aggregate indices, which allows a high degree of reliability of the statistical operation to be obtained.
- 13.2Sampling error
The sampling error, A1, is the coefficient of variation (or standard relative error) of a parameter estimator.
In order to obtain a quality measurement of the indices, an approximate relative sampling error is calculated for the year-on-year variation rates for the turnover and total employed persons variables. The general expression of the estimated relative error, assuming negligible bias, is given by:
is the ratio estimator, given by the quotient of the total estimate of variable Y (turnover or total employed persons) in month m of year t, 
, and the estimate of Y obtained in the same month m of year t-1, 
.
The method used to calculate the variance estimator is Taylor linearisation.The mean sampling error, A1, for 2023 (January - December) of the General Retail Trade Index is:
- Turnover: A1 = 0.75%
- Employment: A1 = 0.47%
- 13.3Non-sampling error
Non-sampling errors are checked throughout the entire statistical process. Specific information on the non-response rate is also available.
A continuous quantitative assessment is carried out of non-sampling errors and risks of bias associated with:
- Lack of coverage, excess coverage and duplicates in the framework.
- Collection tools.
- Total non-response, including causes of non-response and measures to reduce it.
- Partial non-response in the main statistical operation variables.
- Editing, coding and imputing of data.
- Model used in the estimation.
The results of this measurement are analysed in order to carry out relevant actions to reduce the different error types.
An objective measurement is carried out, based on a quantitative indicator (Non-response rate) that is calculated as the percentage assumed by the number of units without information or with unusable information with respect to the total of initially selected sampling units (i.e., discounting framework errors).
Although a reserve sample is available, the rate is only calculated based on collaboration or otherwise of the titular units of the sample, i. e. excluding the units that make up the reserve sample.
A2: Overcoverage rate
The overcoverage rate measures the proportion of units eligible through the framework that do not belong to the target population (are outside the scope).
For the year 2023 the overcoverage rate is A2 = 12.18%
A4: Non-response rate
The average non-response rate A4 is calculated with the Non-Response Rate per unit, which is the ratio of units that do not respond to the total number of units in the sample:
- Average Non-Response Rate, A4 of the first version of the twelve months of 2023: A4 = 14.18%
- Average Non-Response Rate, A4 of the final version for the months between January and October 2023: A4 = 6.97%
A5 Non-response rate per item
This rate is calculated as the quotient between the units of the target population surveyed that have not responded to the turnover or employment question, over the units that have completed the questionnaire totally or partially.
The average non-response rate in 2023 is:
- For turnover: A5 = 0.82%
- For employment: A5 = 0.07%
A7 Imputation rate
The imputation rate measures the percentage of values assigned to companies for which this data is missing, invalid, or inconsistent.
The average imputation rate for the year 2023 is:
- For turnover: A7 = 8.60%
- For employment: A7 = 7.85%
- 14.1Timeliness
The RTI is usually published in the last week of the month following the reference month, thus meeting the deadlines established by Eurostat.
The Opportunity, T1, is the number of days between the last day of the reference period of the data and the day of the first publication.
Mean of TP1 Indicator. Year 2023: TP1 = 29 days
Mean of TP2 Indicator. Year 2023: TP2 = 90 days
- 14.2Punctuality
The RTI is published according to the calendar established by the INE at the beginning of each year.
- 15.1Comparability - geographical
The survey is designed homogeneously throughout the geographical area, in terms of methodology, design, information collection process, and data filtering. This ensures the comparability of the results between the different Autonomous Communities and Cities.
On the other hand, in the European area, comparability between countries is ensured thanks to the Regulation (EU) 2019/2152 of the European Parliamen and of the Council of 27 November 2019 on European business statistics, repealing 10 legal acts in the field of business statistics, which makes the statistics uniform with the rest of the countries in the European Union that publish the same information.
- 15.2Comparability - over time
The RTI was first published in 1995. The base changes carried out since then (base 2001, base 2005, base 2010, base 2015 and base 2021) have modified some methodological aspects of the survey, which has meant gaps in the series that have been suitably treated to offer a linked series from the first year of publication of the survey to the present.
Comparability over time, CC2, is the number of comparable elements in a time series since its last gap.
The number of comparable data, CC2, as of December 2023 was:
- CC2= 288 for the General Retail Trade Index at constant prices
- CC2 =240 for the General Employment Index
- 15.3Coherence - cross domain
When data is validated, information from other statistics is taken into account in order to guarantee consistency between them, such as:
- INE's Annual Services Survey (ASS).
- INE's Labour Force Survey (LFS).
- INE' s Services Sector Activity Indicators (SSAI).
- Household Food Consumption (HFC) of the Ministry of Agriculture and Fisheries, Food and the Environment.
- 15.4Coherence - internal
The consistency between variables is compared at all stages of the statistical process.
Furthermore, the results are checked to ensure that they are consistent with the economic reality of the market and, in particular, with its development in the retail trade sector.
- 16.1Cost and burden
The questionnaire has been designed to include all the necessary information and at the same time to be as simple as possible in order to facilitate its completion by the companies making up the sample. This will help reduce, as far as possible, excessive use of certain respondent units arising from the completion of multiple surveys in the same year.
The response burden endured by the respondent units is continuously monitored, measured as the average time to complete the questionnaire.
To prevent respondent fatigue and sample ageing, allowing the selection of newly created companies, an annual rotation of 20-25% is carried out, i. e. between 20% and 25% of sample units are replaced by new companies.
The budgetary appropriation necessary to finance this statistic, provided for in the 2024 Annual Programme, is 1,973.78 thousand euros.
- 17.1Data revision - policy
The INE of Spain has a policy which regulates the basic aspects of statistical data revision, seeking to ensure process transparency and product quality. This policy is laid out in the document approved by the INE board of directors on 13 March of 2015, which is available on the INE website, in the section "Methods and projects/Quality and Code of Practice/INE’s Quality management/INE’s Revision policy" (link).
This general policy sets the criteria that the different type of revisions should follow: routine revision- it is the case of statistics whose production process includes regular revisions-; more extensive revision- when methodological or basic reference source changes take place-; and exceptional revision- for instance, when an error appears in a published statistic-.
At each publication date, the data from the last three months of the historical series are provisional, with those from the preceding months being definitive.
However, the series adjusted for calendar effects and seasonal and calendar effects are reviewed from 2000 in their entirety every month.
- 17.2Data revision - practice
The first time the index of a given month is published, it is deemed provisional, and does not become definitive until three months later. In this time frame, this index is revised by applying any changes in the data that may have occurred since the first publication date, for example due to the substitution of the estimated data (by management issues) with the real data filled in by the company.
For data revision purposes, the indicator A6 is used, Mean absolute revision, where revision is defined as the difference between the last estimator and the preliminary one. Two estimators are calculated, over a series of reference periods: MAR (Mean Absolute Revision) and RMAR (Relative Mean Absolute Revision with respect to the last estimator).
The MAR, RMAR values of the General Retail Trade Index collected from information for the last 36 months (the last month being considered as December 2023) are:
A6_MAR turnover at constant prices (December 2023): A6_MAR=0.11
A6_RMAR turnover at constant prices (December 2023): A6_RMAR=1.83%
A6_MR turnover at constant prices (December 2023): A6_MR=0.04
A6_MAR calendar adjusted turnover at constant prices (December 2023): A6_MAR=0.13
A6_RMAR calendar adjusted turnover at constant prices (December 2023): A6_RMAR=2.30%
A6_MR calendar adjusted turnover at constant prices (December 2023): A6_MR=-0.04
A6_MAR Employment (December 2023): A6_MAR=0.12
A6_RMAR Employment (December 2023): A6_RMAR=5.84%
A6_MR Employment (December 2023): A6_MR=0.09
- 18.1Source data
To obtain survey data, questionnaires are used for companies whose main activity is registered in Division 47 of Section G of the National Classification of Economic Activities (CNAE-2009).
The sample size has been calculated in order to give indicators of the representative turnover and employment variables. The sample consists of approximately 12,000 respondent units.
Annual rotations of approximately 20-25% of the sample are carried out, where all new companies from the comprehensive strata are incorporated, where those that have been low, unreachable, erroneously included, merged are eliminated and where small companies for which the completion of the questionnaires requires a great effort are replaced.
.The annual rotation process consists of making a new selection of sample units that represents commercial distribution in Spain and a re-weighting of these units so that the sample data is elevated to the population data.
The rotation of the sample for the index calculation takes place in January of each year, at which time the elevation factors and weightings are also updated.
- 18.2Frequency of data collection
Data collection is carried out monthly.
- 18.3Data collection
The respondent companies send their data via the Internet; by ordinary mail (questionnaires completed on paper); or by fax or telephone.
- 18.4Data validation
In the questionnaire completion phase, a system is used to detect possible inconsistencies whereby the respondent is warned and is required to confirm or modify the information provided.
When this information is recorded by INE's own staff, there is a recording control system that warns of possible inconsistencies that may arise. In this process, for any data where there are discrepancies, the staff responsible for collecting the information will contact the respondent to confirm or modify the information provided.
Once all the information has been compiled, a coverage control is carried out in order to guarantee the accuracy of the recorded data, as well as to detect duplicates and coverage errors, non-response, etc.
- 18.5Data compilation
Prior to starting the process for obtaining the indices that will be published regarding this statistical operation, the lack of response is imputed with a figure corresponding to those units that have not provided the information corresponding to the reference month.
Subsequently, with the information received at the INE collection centres, the data filtering process begins. The process consists of two phases: in the first, a microdata filtering system is carried out, while the second consists of an analysis for different levels of aggregation, or macro-filtering.
The macro-filtering consists of checking the validity of data from each company, taking into account the historical series provided by the company itself. The analysis establishes month-on-month and year-on-year comparisons, so that the data is validated without re-contact when its evolution is repeated periodically.
The second part of the filtering is performed once the data is processed together. A centralised or macro-filtering process is carried out with the aggregated information. Unlike micro-filtering, in this phase the weightings of each activity form part of the calculation, taking into account the variation rates for different levels of aggregation, etc. In cases where information is available from other sources, a consistency process is carried out between these and the results of the survey.
As a result of the change of base to the new base of 2021, the weightings have been updated, when the samples for the years 2021, 2022 and 2023 have been updated, the weightings have been recalculated with data from December (t-1) according to these new updated samples, and both the elementary indices and the aggregate indices of these three years have been recalculated.
- 18.6Adjustment
Calendar effect: the impact produced in the time series of a variable, due to the different structure that the months present in the different years (in both length and composition), if the remaining factors influencing said variable remain constant. The RTI indicator is very sensitive to the calendar effect, since one more holiday in a particular month means a proportional decrease in the sales for that month.
To correct this problem and obtain a series that compares production over time in a homogeneous way, the series is adjusted to take into account the following calendar factors: working days, Easter and leap year.
Once the calendar effects are removed, seasonal effects are removed accordingly. Seasonal fluctuations are movements that occur with similar intensity in each month and are expected to continue.
The seasonally adjusted series, i.e., corrected for seasonal and calendar effects, provides an estimate of what is "new" in a series (changes in the trend, cycle, and irregular component).
The method is based on regression models with intervention variables of the three mentioned effects.
The adjusted series is published together with the non-corrected series for the sake of a complete analysis of the situation
metadatosicm_base2015_en.xls
- 19.1Comment