Data sources: Data sources of foreign trade statistics by general trade system:
"Free zone transaction form" used in international transactions of free zones,
"Customs declaration" used in direct transactions with abroad from Turkey's free circulation area, free zones and warehouses,
"Warehouse declaration" used for goods entering to warehouses from abroad,
The common transit system called "new computerized transit system" and "TIR Carnet" used for goods sent from warehouses abroad.
In addition, data of natural gas and electricity imported/exported by public authorities are compiled from related companies. Data of financial leasing are obtained from The Association of Financial Leasing, Factoring and Financing Companies.
Data are still being produced according to the special trade system. The data source is only customs declarations.
Time of recording: Time of recording of export and import is either date which goods cross border (in other words date of customs clearance).
Chapter: The first two digit of Harmonized System (HS) indicates chapter. 99 chapters are used in foreign trade statistics. Chapter 99 is used for national purpose.
Customs: It indicates customs administration where customs procedures carry out.
Country: It means final destination country for exports, country of origin for imports.
Nature of transaction: It means the different characteristics (purchase/sale, work under contract, etc.) which are deemed to be useful in distinguishing one transaction from another.
Type of payment: It refers to how transactions carried out between buyers and salers in foreign trade.
Mode of transport: Transportation system at border.
Customs procedure code: Customs procedure codes are 4-digit codes to make information about the customs procedure applied to individual transactions part of the data set for trade statistics.
Nationality of means of transport at border: It indicates nationality of means of transport carried goods from/to borders.
Free zone: Free zones are the regions set out by the law and excluded from the customs line to increase investment and production for export, to accelerate the inflow of foreign capital and technology, to meet the input needs of the economy cheaply and regularly, and to benefit more from foreign financing and trade opportunities.
Warehouse: Warehouse is place established with the purpose of putting the goods under customs supervision and whose conditions and qualities to be sought in its establishment are determined by the regulation. In addition, warehouses are a customs regime where goods can remain indefinitely if they are placed as regulated by the customs legislation, and taxes are not paid during the time that the goods remain in the warehouse.
Periodicity: It is produced and published monthly.
Timeliness: Timeliness of statistics is compliant with the EU's and other international standards. Publication date is announced to the public with the National Data Release Calendar.
Publication and dissemination: Monthly foreign trade statistics are published 30 days after the reference month.
The National Data Release Calendar for following year is published in the TurkStat web site in December.
The data are disseminated simultaneously to all interested parties through news release, statistical tables and a database.
Confidentiality: According to the Statistics Law of Turkey No: 5429
(1) Foreign trade statistics are published by TurkStat.
(2) TurkStat is authorized in determination of methods and calendar of publication of statistics.
(3) Data is collected for statistical purposes and “passive confidentiality” is used.
According to the Article 13 of Turkish Statistical Law, confidential data can be accessed only by the ones involved in the production of official statistics, to the extent that they need for performing their duties properly. If the number of the statistical unit in any cell of the data table formed by aggregating the individual data is less than three or one or two of the statistical units are dominant even if the number of units is three or more, the data in the concerned cell is considered confidential.
The confidential data compiled, processed and preserved for the production of official statistics cannot be delivered to any administrative, judiciary or military authority or person, can not be used for purposes other than statistics or as an instrument of proof. Civil servants and other staff in charge of compiling and processing these data are obliged to comply with this rule. This obligation continues after the related personnel leave their duties and posts.
The rulers of the institutions and organisations producing official statistics shall take all measures to prevent any illicit access, use or revelation of the confidential data.
Data or information obtained from sources that are open to all people shall not be deemed confidential.
Data confidentiality ceases when a statistical unit gives written approval for the revelation of confidential data concerning itself.
Confidential data can be published only as combined with other data so as not to allow any direct or indirect identification.
(Additional clause: 25/11/2008-5813/2 article)
For the data considered confidential due to the indirect identification in foreign trade statistics, these confidentiality rules are implemented when a statistical unit applies with a written application requiring consideration of its data as confidential.
In principle, suppressions made on commodity code. If this application isn't enough, net mass, partner country, customs can be suppressed.
Because of application of confidentiality, total value related to commodities combined in a Commodity Code under the same chapter, was given in a different group as “confidential data” to prevent any missing value in main group total in classifications. The subgroup values in the mentioned commodities, contain remained commodities' values after subtracted values of confidential data.
Because of application of confidentiality, the data applied confidentiality for partner country are given as “confidential country” and the data applied confidentiality for province are given as “confidential data”.
Identification of internal access to data before release: It is impossible to access to the data before publishing by anybody except staff working for producing foreign trade statistics.
International methods: Foreign trade statistics are produced according to the United Nations' and European Union Statistics Office's (Eurostat) definitions, concepts and methods. The International Merchandise Trade Statistics (IMTS 2010 is used to produce foreign trade statistics.
Identification of commentary on the occasion of statistical releases: Brief comments regarding data are made in news bulletin, otherwise the real interpretation of data is left to users.
Provision of information about revision and advance notice of major changes in methodology: Rules related to foreign trade statistics are determined according to official statistics programme.
Furthermore, by taking attention to additional customs data, in publication of reference period information, revision is made for previous months.
In case of important changes on data coverage and methodology, users are informed by "public announcement" before publication and meta data is also revised.
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 a crucial role in making reliable comparisons between consecutive periods.
The seasonal adjustment of Foreign Trade Statistics is carried out using TRAMO-SEATS methodology. The software that is used for the application of this method is JDemetra+ 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 Foreign Trade Statistics 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.
While 21 subtitles of Foreign Trade series contain both seasonal and calendar effects, 4 subtitles contain neither of these effects, 3 subtitles include only calendar effects.
Direct or Indirect Seasonal Adjustment
Seasonally and calendar adjusted figures of total exports and imports are produced by indirect approach. The individual subtitles of Foreign Trade series by SITC and BEC classification are seasonally adjusted and then aggregated to derive seasonally and calendar adjusted totals. The indirect approach has the advantage of easy calculation of contributions to growth from components of main aggregates and advantage of retaining additivity.
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.
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.