Motivation: For the quarterly national accounts of Turkey, we have traditionally supplemented reported data by various means (extension, seasonal adjustment, annualizing). Our source (the Turkish Statistical Institute, a.k.a. Turkstat) now reports detail that can replace some of our efforts. In particular, the expenditure (GDP(E)) and production (GDP(O)) approaches to GDP now have an analytic variant that is a chain-linked volume index, calendar day adjusted and seasonally adjusted (CDASA).

Response: For our supplements, we have changed from seasonally adjusted (SA) to calendar day adjusted and seasonally adjusted (CDASAA). Other than as described below, properties are unchanged.

1. For current-price series, we calculate annualized versions.
• Before: Seasonally adjusted annualized rates (SAAR).
• Now: Calendar day adjusted and seasonally adjusted annualized rates (CDASAAR).
2. For reported chained volume index CDASA series, extend over interval 1987Q1 to 1997Q4, by:
   1. Calculate CDASA counterparts for not seasonally adjusted (NSA) constant-price levels.
   2. Convert the calculated CDASA levels to index 2009=100.
   3. Extend reported indexes using the growth rates of our calculated indexes.
3. For constant-price series, calculate annualized versions.
• Before: Seasonally adjusted annualized rates (SAAR).
• Now: Calendar day adjusted and seasonally adjusted annualized rates (CDASAAR). Method: Inflate the extended volume indexes (step 2).
4. Revise all periods:
• GDP(E) from 1987.
• GDP(O) from 1998.
5. Update mnemonics to indicate the new adjustment type. For example (old » new):
   • NACSGVATAQ.ITUR » NACSGVATCQ.ITUR = Production approach - GVA - All activities [A to T], (Ths. Ch. 2009 TRY, CDASAAR)

The series reside in the historical catalog (Turkey » National Accounts » by Expenditure | by Value Added » Quarterly » Constant prices | Current prices \ Ch. Vol. Index) and include, for example:

• NAKEFCHNCQ.ITUR  = By expenditure - Final consumption expenditure - Resident households and NPISHs, (Ch. Vol. Index 2009=100, CDASA)
• NACEGDPCQ.ITUR   = By expenditure - Gross domestic product
• NACSGDPCQ.ITUR   = By production - Gross domestic product
• NACSTLSCQ.ITUR   = By production - Taxes less subsidies
• NACSGVAAFCQ.ITUR = By production - Gross value added - Agriculture; forestry and fishing [01 to 03]

Because catalog locations are subject to change, the upper-right search box on DataBuffet.com provides a "find in catalog" mode that accepts a mnemonic.

Please be aware that

If you have legacy retrievals, references with the pattern NACE?AQ.ITUR will now elicit the "series not found" error, and NACS?AQ.ITUR will return only discontinued series. You will need to amend the adjustment character "A" to "C", as described in step (5) above. The Data Buffet basket editor provides a find-and-replace tool.

See also

• Turkey: QNA growth indexes (Aug 2018)
• Turkey: GDP(E) and GDP(O) re-referenced to 2009 (Feb 2017)
• Turkey: GDP(E) and GDP(O) reported CDASA replace supplement SA (Oct 2015)