Purpose: Retail Sales Indices measure sales of retail enterprises of different types and sizes on a monthly basis. Furthermore, it is aimed to follow the development in monthly and yearly basis, to have data consistent with the European Union regulations, to ensure the possibility of international comparisons on Retail Trade Sector.

In addition to measuring the development of Retail Trade sector the indices are also considered as  indicators of consumer confidence and household demand. For this reason, it is accepted as one of the most important indicators to monitor the economic condition.

Retail Sales Indices are involved in European Principal Economic Indicators (PEEIs). The indices are also considered as an important economic indicator in other developed countries besides the EU.
Coverage:  All the enterprises which give VAT declaration to the Revenue Administration are included in the index calculation.

Classifications: The indices are calculated according to the NACE Rev. 2 economic activity classification. The activities covered are as follows.

Retail trade
   Food, drinks and tobacco
   Non-food (except automotive fuel)
       Computers, peripheral units and software, books, telecommunications equipment, etc.
       Audio and video equipment, hardware, paints and glass, electrical household appliances, furniture, etc.
       Textiles, clothing and footwear
       Pharmaceutical goods, medical and orthopedic goods, cosmetic and toilet articles
       Via mail orders and internet
   Automotive fuel

Geographical coverage: The whole country (Turkey) is covered.

Economic activity coverage: The index covers the “Division 47 - Retail Trade (Except Motor Vehicles and Motorcycles)” of NACE Rev.2 activity classification.

The activity groups covered according to the European Union Short Term Statistics regulations are as follows.

 

Code	NACE Rev.2 Composition for Special Aggregates	Description in Releases
G47		Retail trade
G47_FOOD	G4711, G472	Food, drinks and tobacco
G47_NFOOD_X_G473	G4719, G474 to G479	Non-food (except automotive fuel)
G47_NF_OTH1	G4741, G4742, G4753, G4761, G4762, G4764, G4765, G4776, G4777, G4778	Computers, peripheral units and software, books, telecommunications equipment, etc.
G47_NF_OTH2	G4743, G4752, G4754, G4759, G4763	Audio and video equipment, hardware, paints and glass, electrical household appliances, furniture, etc.
G47_NF_CLTH	G4751, G4771, G4772	Textiles, clothing and footwear
G47_NF_HLTH	G4773 to G4775	Pharmaceutical goods, medical and orthopedic goods, cosmetic and toilet articles
G4791		Via mail orders and internet
G473		Automotive fuel

 

A- Reference period and periodicity: The reference period is the period until the last day of each month on the first day and the frequency of the survey is monthly. 

B-  Nature of the indicators

Turnover (VAT excluded): Turnover comprises the total value of goods and services invoiced by enterprise in reference month and this corresponds to market sales of goods and services supplied to third parties. Turnover includes invoiced by unit vis-a-vis its customer (exception of VAT and deductible taxes linked to turnover) other all taxes and duties. Turnover also includes all other charges (transport, packaging, etc.) passed on to the customer, even if these charges are listed separately in the invoice.

Turnover does not include price decline, discount and allowance, recycling package. The income which is classified in the company’s account as other business income, financial income and extraordinary income are excluded in turnover. Business subventions obtained from the government are also excluded.

C- Calculation Method

1- Index type: A simple index is used which is calculated by dividing the relevant levels by the base year averages.

Calculation of volume index: Indices measuring retail sales are produced with constant prices. Volume measurement is obtained by adjusting turnover data from price effects.

In calculation of Retail Sales Indices at current prices are deflated by price relatives. For this purpose, CPI results produced at "Classification of Individual Consumption According to Purpose (COICOP)" level are calculated according to NACE Rev.2 level. "Household Budget Survey" data is used for this transition.

As a result of deflating current price Turnover Index by price relatives at appropriate levels, Retail Sales Volume Index with constant prices is reached. Since the price indices used are compiled as VAT included, the Turnover Indices are also calculated in VAT included form before deflation process. Thus, the possible changes in the VAT rates do not affect the volume measure.

3- Source of weights: Not available

4- Impact and Contribution analysis: Impact and contribution analysis are done on enterprise basis by sectors.

5- Imputation:  Incorrect data or outliers  in administrative records are corrected by statistical methods. No imputation is done for non-respondence
 

Data sources: VAT declarations obtained from the Revenue Administration are used as the data source for the compiling of retail sale indices.

Method of weighting:  Not available

Sampling and full enumeration: Full enumeration

Aggregation: Retail Sales Indices are aggregated for food, drinks and tobacco;   non-food (except automotive fuel); automotive fuel activities of NACE Rev.2 classification and for Retail Trade in general.  
 

Data compilation: VAT declarations are compiled monthly from Revenue Administration.
 

The Revision Information Form regarding the revisions to be carried out in the current year for the statistics produced in the scope of this press release can be accessed from the link below.
 
https://www.tuik.gov.tr/indir/revizyon/2020_RBF_EN_KDIIDB_CHGG_PSE.pdf
 

Seasonal Adjustment 

Seasonal and calendar related effects prevent observing the general tendency of data because of their temporary characteristics. Therefore, identification of seasonal patterns of short term indicators plays crucial role in order to make reliable comparisons between consecutive periods 

Method Used

The seasonal adjustment of Retail Sales Indices is carried out using TRAMO-SEATS methodology. The software that is used for the application of this method is JDemetra+2.2.2 developed by the National Bank of Belgium (NBB) in cooperation with the Deutsche Bundesbank and Eurostat in accordance with the Guidelines of the European Statistical System.

Seasonal Adjustment Process

Seasonal and calendar adjustment process of Retail Sales Indices begins at the end of each year with the identification of the models of next year.  This specified model structure is kept fixed throughout the year to adjust seasonally and/or calendar effects. At the end of the year, just like the previous year, specification of econometric estimation models for the following year is done. The identified process repeats itself in a cyclical manner each year.

The indices are seasonally and calendar adjusted at retail trade in general, food, drinks and tobacco, non-food (except automotive fuel), computers, peripheral units and software, books, telecommunications equipment, etc., audio and video equipment, hardware, paints and glass, electrical household appliances, furniture, etc, non-food, retail trade (except automotive fuel), non-specialised shops and automotive fuel activities. While all subtitles of Retail Sales Indices contain both seasonal effects,  20 subtitles contain calendar effect. 

Direct or Indirect Approach

The approach in seasonal and calendar adjustment for Retail Sales Indices is indirect. Namely, the individual subtitles of retail trade series are seasonally adjusted and then aggregated to derive seasonally and calendar adjusted totals. The advantages of the indirect approach are easy calculation of contributions to growth from components of main aggregates and retaining additivity.

Revision Policy

Seasonal adjustment procedure is subject to revisions over time because of the re-estimation of seasonal component as new observations are added. These revisions are implemented on the data of the last three years excluding the current year.

Publication

Adjusted data has been published in 3 different ways. “Calendar adjusted” data is derived from unadjusted data by removing calendar and holiday originated effects. Calendar adjusted data should be used in comparisons regarding the same month/period of the previous year.

“Seasonally adjusted” data is derived from unadjusted data by removing effects originating from seasonal effects. Seasonally adjusted data should be used in comparisons regarding the previous month/period.

If unadjusted data contains both calendar and holiday, and seasonal effects, “seasonally and calendar adjusted” data is derived by removing these effects. Seasonally and calendar adjusted data should be used in comparisons regarding the previous month/period