Methodology Introduction
First: Scope
Second: Design
Third: Organization
Fourth: Collection
Fifth: Disaggregation
Sixth: Reviewing
Seventh: Publication
Eighth: Assessment
Ninth: Management
Introduction:
The General Authority for Statistics (GaStat) applies in all its statistical work a unified methodology that conforms with the nature of each statistical product. It depends on the Handbook of Statistical Work Procedures, which is compatible with internationally approved procedures. Statistical products go through eight major stages, in addition to a ninth stage represented in the comprehensive “management” stage which is illustrated in the following figure and the subsequent explanations:
The first three stages (scope, design and organization) are collaborative stages between GaStat and its clients who are data users from development entities. The fourth stage (data collection) is a collaborative stage between GaStat and the statistical population, whether they are households or establishments, to take data and information. The remaining stages (classification, reviewing and publication) are statistical and are undertaken by GaStat. Afterwards, the eighth stage (assessment) is done in collaboration with the clients. The management stage is administrative and organizational and spans all other stages. Those stages have been applied in the wholesale price index bulletin as follows:
First Stage: Scope
It is the starting point for producing the wholesale price index. It is also the first collaborative stage between GaStat and a number of competent government bodies, such as the Saudi Arabian Monetary Authority, the Ministry of Economy and Planning and the Ministry of Commerce and Investment. Workshops and meetings were held at this stage between the authority and those bodies to reach a better understanding of their needs and know their requirements, given that they are the main beneficiaries of the data. The views of those bodies are taken into consideration to ensure the attainment of all the goals of the wholesale price index which are summed up as follows:
1. To provide statistics on the movements of commodity prices in the stage preceding wholesale.
2. To provide a time series of statistical data on wholesale price indices.
This stage also involves ensuring that the published statistics will contribute to meeting the requirements of Saudi Vision 2030 as well as covering regional requirements, such as the wholesale price index of the GCC Statistical Center, and international requirements represented in the International Monetary Fund.
Stage Two: Design
It is the stage of designing statistical work as an integrated product. It also involves identifying the statistical population, designing the statistical framework and the survey sample, designing the survey questionnaire, identifying the method and tools of data collection and identifying the sampling units. Clients are made partners in all those procedures to benefit from their observations to meet all requirements and ensure that they are part of the statistical product.
The most important outputs of this stage are:
1. The Statistical Population:
The statistical population in the wholesale price index bulletin consists of all wholesale points of sale in the Kingdom.
2. Statistical Sources:
The wholesale price index uses in its data the field survey of wholesale price index, which is a field survey conducted by GaStat monthly and is listed under the classification of economical statistics. The survey involves collecting prices through visiting wholesale shops in three cities (Riyadh, Jeddah and Dammam) representing all wholesale points of sale in the Kingdom, completing an electronic questionnaire that includes a number of questions and providing indicators related to the wholesale price index.
3. Setting the Base Year:
The year 2014 was set as a base year as it meets the required conditions in terms of economic and social stability and witnessed no crises.
4. Terminology and Concepts of the Wholesale Price Index:
4.1. Price Index: It is a rational number that measures variation in the prices of a set of commodities and services and is obtained by dividing the prices of commodities in the comparison period by their prices in the base period.
4.2. Wholesale Price Index: It is a statistical tool for measuring the variation rate in the prices of local and imported commodities in primary markets (wholesale) between two different periods of time.
4.3. Commodity Basket: It is a set of commodities chosen according to their importance in the import balance and the local product value evaluation.
4.4. Points of Sale: They are the establishments where data are collected on wholesale prices of commodities within the basket of the wholesale price index program.
4.5. 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.
4.6. Comparison Period Price: It is the recorded price of a commodity in the current period of time.
4.7. Base Period Price: It is the recorded price of a commodity in a previous period of time with which the current price is compared.
4.8. Base Year: It is the year whose prices are the divisor of the comparison period prices.
5. Indicators:
6. Adopted Statistical Classification:
Classification is defined as being an arranged set of related categories used for data collection according to similarity. It is the basis for collecting and publishing data in all statistical fields, such as economic activity, products, expenditures, jobs or health, etc. It allows for classifying data and information through putting them into meaningful categories to produce useful statistics, considering that data collection requires precise and methodological arrangement in accordance with their common features so that the statistics can be reliable and comparable. The wholesale price index is subject to the following classification:
The Central Product Classification (CPC2) issued by the United Nations in 2008:
The Central Product Classification forms a complete classification of products that includes commodities and services. The purpose of this classification is to be an international standard to accumulate and disaggregate all types of data that require product details, including industrial production, national accounts, service industries, local and foreign trade of basic commodities, international trade of services, balance of payments, consumption and price statistics. The other primary purposes are to provide a framework for international comparison and encourage coordination between all types of statistics on commodities and services.
7. Weighting (Relative Importance):
Considering that the adopted method for index calculation depends on a mathematic formula known as Laspeyres formula, the required data should be provided to extract and calculate the weightings necessary for that equation. The volume of locally produced commodities with regard to economic activities as well as the imported commodities circulated in wholesale markets are used.
The required weights are extracted using the value of locally produced commodities in the sectors of agriculture and industry as well as the imported commodities which are disaggregated according to the Central Product Classification (CPC2).
It is noteworthy that commodity weight is the ratio of commodity value to the total value of imported commodities and locally produced commodities within the wholesale trade, being calculated as a ratio of ten thousand.
Weights are extracted at a detailed level so that they can encompass items, activities, subclass, class, group, division and section.
8. Designing Survey Questionnaire:
The questionnaire of collecting wholesale price index data was prepared and designed by price statistics specialists at GaStat. The design took recommendations and international standards and definitions into account. The questionnaire was also presented to the concerned parties to get their observations and remarks about it. The question wording was prepared in a specific scientific method with the aim of unifying the manner in which researchers direct questions.
The questionnaire includes auxiliary geographic data to arrive at the points of sale. It also includes a description of the commodity or service whose price, specifications and unforeseen changes need to be monitored, in addition to price factors.
The complete questionnaire can be read and downloaded via GaStat’s official website.
After being approved, the survey questionnaire will be transformed into an electronic questionnaire that can be handled through the advanced data collection system using tablet devices. The system has the following features:
1. Reviewing the work zone of the field researcher (survey sample).
2. Reaching the sample (point of sale) using the map on the tablet device.
3. Completing the data with high quality using data auditing and navigation rules to automatically detect input errors and inconsistent inputs when the data are completed.
4. Communicating with supervising entities by exchanging remarks with the field researcher.
9. Coverage:
9.1. Spatial Coverage:
The wholesale price index bulletin covers data on wholesale prices in the Kingdom’s three major cities which are Riyadh, Jeddah and Dammam.
9.2. Temporal Coverage:
The prices of most basket items are collected monthly as the accumulated data are attributed to the calendar month in which the price data are collected.
10. Statistical Framework:
Points of Sale Framework:
The framework includes all wholesale shops in the three cities (Riyadh, Jeddah and Dammam). The establishment search results are used to identify wholesale shops.
Item Framework:
It is the set of commodities of the wholesale price index program that are disaggregated according to the Central Product Classification (CPC2). It consists of all major business dealings made in the primary markets of the Kingdom of Saudi Arabia in respect of locally produced or imported commodities. A framework including the whole items and their relative importance was set on the basis of foreign trade lists of items of exports and imports and also lists of agricultural products from the Ministry of Agriculture.
11. Sample design:
Points of Sale Sample:
A list obtained through the economic search of establishments in Riyadh, Jeddah and Dammam was used as a sampling frame for the points of sale. Afterwards, those points are contacted to determine their appropriateness to every item. In light of that, seven points of sale were chosen in every city for every item.
Item Sample
On the basis of the foreign trade lists of items of exports and imports and also the lists of agricultural products from the Ministry of Agriculture, a framework including the whole items and their relative importance was set. In light of that, a commodity basket including 343 commodities was chosen based on the relative importance of each item in it. They are listed in their place within the general structure of the Central Product Classification (CPC2) as follows:
Third Stage: Organization
It is the final preparation stage and precedes the visits to establishments (points of sale) and data collection. In this stage, the required workflow procedures are established for preparing the survey of collecting wholesale price index data, starting with the collection stage and ending with the assessment stage and the organization and grouping of those procedures. The optimal sequence of those procedures is chosen to arrive at a methodology that achieves the goals of the wholesale price index. A review was made in this stage of the procedures that were taken upon the preparation of the previous version of the wholesale price index to develop the work procedures in the current version. Those procedures were also described and documented to facilitate any updates in future rounds. The statistical workflow procedures were tested and examined to ensure their compliance with the requirements of preparing the wholesale price index in its final form, approve the procedures of the statistical workflow, and put a road map for implementation.
Testing the efficiency of input systems and the process of transmitting, synchronizing and reviewing data through the tablet system or the office system of the wholesale price index are the main procedures in this stage.
Fourth Stage: Collection
First: The process of collecting prices for the sample of selected items is done monthly from the sample of points of sale that represent primary markets in the Kingdom of Saudi Arabia at the amount of 7 prices for each commodity in each of the three research cities: Riyadh, Jeddah and Dammam.
Second: The workers, who were nominated as field researchers and visited the establishments (points of sale) to collect the wholesale price index data, were chosen on the basis of several practical and subjective criteria related to the nature of work, such as:
• Educational level.
• Fieldwork experience.
• Personal attributes, such as good conduct, evidence of senses and physical and psychological fitness.
• Nominee’s success in the training program of the wholesale price index.
• The nominee shall not be under the age of 20.
Third: All nominees (GaStat staff and collaborators from some government entities) were qualified and trained through special training programs as follows:
• A training program was held for competent staff members in GaStat headquarters for one week.
• Similar training programs were held for collaborating inspectors, observers and researchers from all survey cities.
Fourth: The method of direct contact with the managers of the points of sale was adopted in the process of completing the survey questionnaire and data collection. Field researchers visit the points of sale located within the survey sample after arriving at them using the coordinates recorded on the tablets and the guiding maps and introducing themselves and showing official documents proving their statistical identity. They will also clarify the aim of their visit, present an overview of the survey and its objectives and complete the electronic questionnaire through verbal discussion with the managers of the point of sale.
Fifth: All field researchers use tablet devices to complete the survey questionnaire data.
Sixth: Field researchers at all work locations in the Kingdom use the “synchronization” feature available on tablet devices to download and transfer the completed data of the points of sale directly to the database linked to them at GaStat’s headquarters where they are stored in a specific way to be reviewed and processed at a later stage.
Seventh: Check rules are applied electronically to guarantee the consistency, precision and rationality of the data of the wholesale price index questionnaire. They are electronic rules that identify contradictions between answers and were built through linking the logical relationship between the answers to the questionnaire and its variables to help field researchers directly identify any errors upon completing the survey data with the manager of the point of sale. Those programmed rules don’t allow any errors to go through when an answer contradicts with another piece of information or another answer in the questionnaire.
Eighth: Collected data are verified by being reviewed by the field researcher himself and the survey supervisor in the supervision city. All work areas were subjected to a process of monitoring and reviewing by the Price Statistics Department at GaStat’s headquarters. The department also controls and monitors the performance of all working groups in the field in synchronization with the time of performing the data collection process starting from the first day to the last.
Fifth Stage: Disaggregation
The processes of disaggregating the raw data of the wholesale price index use inputs of classification and coding formed during the data collection process, whether the adopted statistical classification is the one being referred to in the design stage, i.e. the Central Product Classification (CPC2) issued by the United Nations in 2008 or any other classification like the geographic data classification (for instance data distribution at the level of survey cities). The data are displayed in suitable tables so that they can be easily summed up, understood and comprehended to obtain results from them, compare them with other data and extract statistical indications from them about the study community. It will also be easy to refer to them as tables without the need to read the original questionnaires which often include some data, such as the addresses of establishments in violation of the principle of statistical data confidentiality.
Data is processed at this stage through taking a number of steps, mainly:
First: Verifying data comprehensiveness and rationality:
Data are reviewed in terms of their comprehensiveness and rationality and matched to ensure their accuracy and precision in a way that suits their nature. The data of the current round (current month) are matched with the data of the previous round (previous month) to verify them as a prelude to processing data and extracting and reviewing results in the stages that follow the disaggregation stage.
Second: Data anonymization:
To ensure data confidentiality, identifiers are removed from a set of input data, such as hiding the names of individuals, points of sale, addresses and other identifiers to ensure the protection of people’s privacy.
Sixth Stage: Reviewing
First: Verifying data outputs:
After reviewing the accumulated data of the wholesale price index and verifying them, this stage involves processes of calculating and extracting results and uploading the outputs and storing them on the database. Afterwards, final reviewing processes are conducted by specialists in price statistics using modern technologies and software designed for the purposes of reviewing and checking.
Second: Handling of confidential data:
Pursuant to Royal Decree No.23 dated 07/12/1397, GaStat is committed to the absolute confidentiality of all completed data and not using them except for statistical purposes. Therefore, data are safely stored on GaStat’s servers.
Seventh Stage: Publication
First: Preparing and setting data for publication:
In this stage, data results are uploaded from the database of the price statistics software. Afterwards, publication tables and graphs for data and indicators are set and prepared and have descriptive and methodological data added to them in Arabic and English.
Second: Preparing media material and announcing the date of releasing the bulletin:
GaStat announces the date of releasing the bulletin on its official website at the beginning of the calendar year. The authority also prepares in this stage the media material of the announcement of issuing the bulletin on all media outlets as well as its various social media platforms. The announcement is made on the release date. The bulletin is published on the official website in various templates as open data in Excel format and data in PDF format
to guarantee its circulation and accessibility to all clients and parties interested in price statistics. The bulletin is included in the website’s statistics library.
Third: Communicating with the clients and providing them with the bulletin:
GaStat pays great importance to communicating with the clients who use the data. Therefore, GaStat communicates with the clients upon the release ofthe wholesale price index bulletin to provide them with it. GaStat also receives the clients’ questions and enquiries about the bulletin and its results through all communication channels so that clients can communicate with the authority to request data. Questions and inquiries are received via:
- GaStat website: www.stats.gov.sa
- GaStat email: info@stats.gov.sa
- Client support email cs@stats.gov.sa
- Visiting GaStat’s headquarters in Riyadh or one of its branches in the regions of the Kingdom.
- Official Letters.
- By Statistical Phone (920020081)
Fourth: Preserving the published content:
GaStat’s Documents and Archives Center stored and archived the data of this bulletin to refer to it at any time on request. GaStat took that step out of its awareness of the importance of electronically preserving those data to easily refer to them when needed.
Eighth Stage: Assessment
After the bulletin is released and received by all GaStat’s clients, the clients are contacted again in this stage which allows for assessing the whole statistical process that was carried out, with the aim of constant improvement to obtain high-quality data. The improvements may include methodologies, processes, systems, statistical researchers’ skill and statistical frameworks. This stage is done in collaboration with data users and GaStat’s clients through a number of steps:
First: Collecting measurable assessment inputs:
Main comments and remarks are collected and documented from their sources at all stages, including those collected and documented during the collection stage, such as comments and remarks presented by data collectors and their field supervisors, in addition to data collected and documented during the assessment stage such as the remarks deduced by specialists concerned with reviewing, checking and analyzing data collected from the field. Finally, comments and remarks presented by data users are collected and documented after publication, in addition to what is being monitored via media outlets or the clients’ remarks which GaStat receives through its main channels.
Second: Making the assessment:
Collected assessment inputs are analyzed, and the results of such analysis are compared with pre-anticipated results. On that basis, a number of improvements and possible solutions are defined and discussed with specialists and experts. The concerned parties are also engaged in the matter. This step also involves performance measurement of the clients’ use of the results of the wholesale price index and their satisfaction with it. An agreement will be made on the basis of those procedures on the suggested recommendations to obtain high-quality data in the coming results of the wholesale price index.
Ninth Stage: Management
This stage is comprehensive and spans every stage of producing the wholesale price index. It involves drawing up the general production plan which includes feasibility study, risk management, means of funding and spending mechanisms, as well as developing performance indicators, quality parameters, human resources map necessary for production, following up on the execution of tasks assigned to all departments in every stage, and making reports to ensure that the authority fulfills its commitments towards its clients.
عنوان الملف:
Metadata Report of Wholesale Price Index (WPI)
نوع الصفحة:
بيانات الوصفية