Methodology and Quality Update

Methodology and Quality last update 

2025/05/22   

Statistical Presentation

Data description  

The Wholesale Price Index presents data on wholesale prices in Saudi Arabia.
Wholesale Price Index is a survey conducted to collect data on the basic characteristics as follows:
•    Providing statistics on commodity price movements at the pre-retail stage.
•    Providing a time series of statistical data on wholesale price indices.
Data is also used to estimates:
•    Monthly and annual index of wholesale prices by sections.
•    Monthly and annual index of wholesale prices by divisions.
•    Monthly and annual index of wholesale prices by groups.
•    Monthly and annual index of wholesale prices by categories.
•    Monthly and annual index of wholesale prices by subcategories.
•    Monthly and annual index of wholesale prices by items.
•    Annual average of wholesale prices by sections.
•    Annual average of wholesale prices by divisions.
•    Annual average of wholesale prices by groups.
•    Annual average of wholesale prices by categories.
•    Annual average of wholesale prices by subcategories.
•    Annual average of wholesale prices by items.
•    The annual average of the wholesale price index is published at the end of each calendar year.

Classification system

Apply the following classifications in the Wholesale Price Index.
Central Product Classification (CPC2) issued by the United Nations in 2008: 
Detailed data is collected through interviews to allow for the production of outputs according to all relevant classifications.
The classifications are available on the GASTAT’s website: www.stats.gov.sa

Sector coverage

The Wholesale Price Index (ISIC4) covers the following major economic sectors:
•    Agriculture, and fishing.
•    Ores and minerals.
•    Food products, beverages, tobacco, and textiles.
•    Other transportable goods, except metal products, machinery and equipment.
•    Metal products, machinery, and equipment.

Statistical concepts and definitions

Terms and concepts of the Wholesale Price Index:
•    Price index:
An index number that measures the change in prices of a set of goods and services, obtained by comparing the prices of the goods in the comparison period to their prices in the base period.
•    Wholesale price index
A statistical tool for measuring the percentage change in prices of locally produced and imported goods in primary markets (wholesale markets) between two different time periods.
•    Commodity Basket:
It is a set of commodities chosen according to their importance in the import balance and the local product value evaluation. 
•    Points of sale:
Establishments or units from which wholesale price data for the goods included in the wholesale price index program basket are collected.
•    Shadow sample:
It is a set of backup points of sale which can be referred to when needed to replace one of the basic points of sale when it becomes difficult to get the price from that point for any reason, whether because the shop is closed permanently or because the commodity is definitely unavailable.
•    Comparison Period Price:
It is the recorded price of a commodity in the current period of time.
•    Base Period Price:
It is the recorded price of a commodity in a previous period of time with which the current price is compared.
•    Base year:
It is the year whose prices are the divisor of the comparison period prices.

Statistical unit

A statistical unit is a commodity at the point of sale.

Statistical population

It is all goods at the point of sale at the wholesale price determined by the economic research of the enterprises in the four cities (Riyadh, Jeddah, Dammam, Khobar).

Reference area

The survey covers 4 cities: (Riyadh, Jeddah, Dammam, and Khobar).

Time coverage

Data are available from 2015 to the current month of 2025.

Base period

The base year used to calculate the Wholesale Price Index is 2014.

Unit of measure

All results are reported as percentage (such as: The monthly change and the annual change).

Reference period

References period to the variables or dataset as following:
The collected data is based on the calendar month in which the price data is collected, and the results of the wholesale price indices and at all levels are published monthly.

Confidentiality

Confidentiality - policy

According to the Royal Decree No. 23 dated 07-12-1397, data must always be kept confidential and must be used by GASTAT only for statistical purposes.
Therefore, the data are protected in the data servers of the Authority.

Confidentiality - data treatment

Data are displayed in appropriate tables to facilitate its summarization, comprehension, results extraction, comparison with other data and coming up with statistical connotations for the study community. It is also easier to check tables without the need to see the original questionnaire, which usually include data like names and addresses of individuals, names of data providers, which violates the confidentiality of statistical data.
“Anonymity of data” is one of the most important procedures. To keep data confidential, GASTAT removed personal information of individuals, households, or business entities in a way that does not allow the identification of the respondent either directly (by name, address, contact number, identity number etc.) or indirectly (by combining different - especially rare - characteristics of respondents: age, occupation, education etc.).

Release policy

Release calendar

The Wholesale Price Index is included in the statistical calendar.

Release calendar access

The release calendar is available at: https://www.stats.gov.sa/statistical-calendar-releases

User access

One of GASTAT’s objectives is to better meet its clients' needs, so it immediately provides them with the publication’s results once the Wholesale Price Index Publication is published.
It also receives questions and inquiries from the clients about the Publication and its results through various communication channels, such as:
•    GASTAT’s official website: www.stats.gov.sa
•    GASTAT’s official e-mail address: info@stats.gov.sa
•    Client Support’s e-mail address: info@stats.gov.sa
•    Official visits to GASTAT’s official head office in Riyadh or one of its branches in Saudi Arabia.
•    Official letters.
•    Statistical telephone (199009).

Frequency of dissemination

•    Monthly.
•    The annual average of the wholesale price index is published at the end of each calendar year.

Accessibility and clarity

News release

The announcements of each publication are available on release calendar as mentioned in 7.2. Release calendar access. The news release can be viewed on the website of GASTAT through the following link:
https://stats.gov.sa/news

Publications

GASTAT issues publications and reports on the Wholesale Price Index on a regular basis within a pre-prepared dissemination plan and are published on GASTAT’s website. GASTAT is keen to publish its publications in a way that serves all users of different types, including publications in different formats that contain (publication tables, data graphs, indicators, Methodology and Quality Report, and questionnaires) in both English and Arabic.
The results of the Wholesale Price Index are available at:
https://www.stats.gov.sa/statistics

On-line database

The data is published on the statistical database:
GASTAT (stats.gov.sa)

Micro-data access

 Microdata are unit-level datasets derived from surveys, censuses, and administrative records. These datasets provide detailed insights into individuals, households, businesses, and geographic areas, supporting the development of statistical indicators and in-depth research.
The different types of microdata files to meet different information needs:
•    Public use:
It consists sets of records containing information on individual persons, households, or business entities anonymized in such a way that the respondent cannot be identified either directly (by name, address, contact number, identity number etc.) or indirectly (by combining different - especially rare - characteristics of respondents: age, occupation, education etc.).
•    Scientific use:
These files established based on specific methodology asked by data requester to extract the datasets with specific characteristics used for strategic studies and decision making as well scientific research purposes on individuals, households and enterprises with no direct identifiers, which have been subject to control methods to protect confidentiality.
Access to Scientific Use Files (SUF) is restricted to authorized researchers who comply with ethical and confidentiality standards. Representative samples of SUF can be obtained through GASTAT's secure platform, "Etaha," while more sensitive datasets are accessible only through secure physical lab environments managed by GASTAT.

Other

Not available.

Documentation on methodology

The Wholesale Price Index in its data on the field survey of the Wholesale Price Index, a field survey conducted by the General Authority for Statistics on a monthly basis, falls under the classification (economic statistics) in which prices are collected by visiting wholesale stores in the three cities (Riyadh, Jeddah, and Dammam) representing all points of sale at the wholesale price in the Kingdom. complete an electronic form containing a number of questions, through which indicators related to the wholesale price index according to the Central Product Classification (CPC2(issued by the United Nations in 2008: 
Methodology of the Wholesale Price Index Statistics

Quality documentation

Quality documentation covers documentation on methods and standards for assessing, measuring, and monitoring the quality of statistical process and output. It is based on standard quality criteria such as relevance, accuracy and reliability, timeliness and punctuality, accessibility and clarity, comparability, and coherence.

Quality management

Quality assurance

GASTAT declares that it considers the following principles: impartiality, user orientated, quality of processes and output, effectiveness of statistical processes, reducing the workload for respondents. 
Quality controls and validation of data are actions carried out throughout the process in different stages such as (data input and data collection and other final controls (.

Quality assessment

GASTAT performs all statistical activities according to a national model (Generic Statistical Business Process Model – GSBPM). According to the GSBPM, the final phase of statistical activities is overall evaluation using information gathered in each phase or sub-process. This information is used to prepare the evaluation report which outlines all the quality issues related to the specific statistical activity and serves as input for improvement actions.

Relevance 

User needs 

Internal GASTAT’s users, who make use of Wholesale Price Index data, include:
National accounts.
External users who make significant use of Wholesale Price Index data include:
•    The governmental entities.
•    Regional and International Organizations.
•    Research institutions.
•    Media.
•    Individuals.

The disseminated key variables that mostly used by key users: 

User satisfaction

Not available.

Completeness

 Wholesale Price Index data are collected from the field by wholesale point units in search cities Riyadh, Jeddah, Dammam, and Khobar, and the data are complete at the end of each calendar month.

Accuracy and reliability 

Overall accuracy

The data collected is improved through the researchers, that have been selected according to a set of practical and objective criteria and training program related to the field of work.
Alert and validation rules are applied during the data collection process on the electronic questionnaire for the (Wholesale Price Index to enhance data quality.
Data is checked with previous years to identify any significant changes in the data. The internal consistency of the data is checked before it is finalized. The links between variables are checked and coherence between different data series is confirmed.

Timeliness and punctuality

Timeliness

GASTAT uses the Special Data Dissemination Standard (SDDS) issued by the International Monetary Fund. According to this Standard, all statistics agencies are required to publish data on an annual basis, and with a delay of not more than mid of year (30 days) after the end of the reference period. If the data are from different source, they may be published in a different frequency.

Punctuality

The publication is done according to the publication dates in the statistical calendar published for the Wholesale Price Index on the website page of the General Authority for Statistics. The data are available at the expected time, as scheduled in the statistical release calendar, If the publication is delayed, reasons shall be provided.

Coherence and comparability

Comparability - geographical

Data are fully comparable.

Comparability - over time

The survey began in 1985 and the first record publication was published during the first quarter of the same year for a series of 57 items.
•    1988:
The number of goods has been increased to 160 items, as the program covers major cities (Riyadh, Jeddah, Dammam)
•    2014:
The base year has been updated and the number of goods has been increased to 343 items.

Coherence- cross domain 

Not applicable.

Coherence - sub annual and annual statistics

Not applicable.

Coherence- National Accounts

Not applicable.

Coherence - internal

The Wholesale Price Index estimates have full internal coherence, as they are all based on the same corpus of microdata, and they are calculated using the same estimation methods.

Resources used

Data revision

Data revision – policy

Not applicable, only final results will be published.

Data revision – practice

Not applicable, only final results will be published.

Statistical processing

Source data

The data is collected through field visits to the sample wholesale price index survey consisting of (points of sale) that included the four cities (Riyadh, Jeddah, Dammam, Khobar).In addition to secondary sources.
The main variables:
•    Wholesale price indices by cities, sections, divisions, groups, and categories.
•    Wholesale price indices and monthly rates of change.
•    Wholesale price indices and annual rates of change.

Frequency of data collection

Monthly.

Data collection

Data collection from survey:
The Wholesale Price Index data is collected through computer-assisted Personal Interviews (CAPI).
The data is stored in the authority's databases after undergoing auditing and review processes following approved statistical methods and recognized quality standards. If errors or discrepancies are discovered, the data is cross-referenced with the data source for correction or clarification.

Data validation

Data are reviewed and matched to ensure their accuracy and precision in a way that suits their nature with the aim of giving the presented statistics quality and accuracy. 
The data of the current year publication are compared with the data of the previous year to ensure their integrity and consistency in preparation for processing data and extracting and reviewing results.
In addition to the data processing and tabulation to check their accuracy, all the outputs are stored and uploaded to the database after being calculated by GASTAT to be reviewed and processed by specialists in the price statistics department through modern technologies and software designed for this purpose.

Data compilation

Data Coding:
In the Wholesale Price Index, researchers collect from respondents, a detailed description of each field. This information is then coded in-house by an automated process, which is reviewed by a small-dedicated team of coding experts using a series of consistency checks.
Data editing:
Specialists of the Prices Statistics Department have processed and analyzed data in this stage, and this step was based on the following measures:
•    Sorting and arranging data in groups or different categories in a serial order.
•    Summarizing detailed data into key points or data.
•    Combining many data segments and ensuring their interconnection.
•    Processing incomplete or missing data.
•    Processing illogical data.
•    Converting data into statistically significant data.
•    Arranging, presenting, and interpreting data.
Compensation (for incomplete and lost data set):
In case there is no current price for any reason, the treatment is to calculate the monthly change of the engineering medium for the prices of the current month compared to the engineering average of the prices of the previous month.
Applied statistical estimation:
GASTAT has relied on the formulas approved by the international standards in calculating Wholesale Price Index statistics key indicators, as follows:
•    Geometric Laspeyres Formula:
 
  
 

Adjustment

Not applicable, only final results will be published.