Definition: Consumer Price Index (CPI) measures the changes of the current retail prices of goods and services purchased by consumers over a given time period. 2003 based CPI is aimed to calculate the inflation rate by using the change of the prices of goods and services existed in the market. For this purpose, all final monetary consumption expenditure of households, foreign visitors, institutional population within the country are taken into account. This concept left the owner occupied housing and expenditures from household production out of the coverage from the consumption expenditures.

Classification: In determining the weights and calculating the index, Classification of Individual Consumption by Purpose (COICOP) is used and according to this classification expenditures are organized in 43 sub-groups and 12 major groups. 415 products are used in the compilation of the index.

International and regional guidelines: There are no important differences between Turkey's methodology reported in the EUROSTAT and relevant international or regional standards.

Sources of weights: Continuous Household Budget Survey conducted by the Turkish Statistical Institute (TURKSTAT) yearly 15 000 private households of all socio-economic groups (3-year total data are used), tourism survey, constitutional population expenditure survey and administrative records records updated with growth rate of National Accounts Household Final Consumption Expenditure.

Strict annual weight approach is used for seasonal items.

Time period of current weights: From the period January (t-4) to December (t-2) (1/3 from (t-4), 1/3 from (t-3), 1/3 from (t-2)) is updated to (t-1) by using National Accounts Household Final Consumption Expenditure (t-1)/(t-2) growth rate.

Transactions coverage: In 2003=100 based CPI, all of the final monetary consumption expenditures made for the consumption of goods and services in the domestic markets are taken as bases. In the index 225 district centers consisted all of the 81 city centers are included. 550 632 prices are compiled from 27 980 outlets in a month and 4 274 tenants are included in the scope of the index. Number of outlets and prices can change during the year because of seasonality.

Population coverage: Index coverage of the population is the whole population of Turkey without any groupings according to income level or geographical areas. 

Geographical coverage: All of the final monetary consumptions of the households, foreign visitors and institutional population are taken into account.

Price Coverage: Price coverage of index is constituted of purchasing prices. The prices of goods and services included within the index are retail prices including taxes but excluding any deposits and installments.

Item baskets and the weights are updated at the end of every year and chained with the Laspeyres formulation. Every year in December new goods and services are added in the basket, goods and services which lost their importance are taken out and renewed weights are used in the calculation of index. Index is calculated by dividing current prices to the prices of previous December, which is “new price reference period (po)”, and then chained by multiplying it with the index numbers of December.

I = w . P_i / Po                                      

I : index

P_i : current price             

w : weight

Po: base year price

                                                                        

It = w^ı  .   P_it  /  P_December(t-1)   .  I_{December(t-1)}

w^ı : new weight

t : time

Geometric average is used for the computations of commodity prices from commodity 

Sources: Data sources of CPI basket and weights are household budget survey, institutional population individual consumption survey, foreign visitors survey, administrative data (cigarettes, insurances, games of chance etc.) and scanner data of chain markets.

Processing system: Prices of fresh fruit, vegetables, fee paid for watching sport games (football), LPG, tube gas and 16 specific items are collected once a week; other prices are collected twice a month. Prices of cigarettes, jewelry (gold), diesel and petrol products are collected on daily basis.

Processing site: Turkey's Consumer Price Index data are processed only by the Turkish Statistical Institute.

Timing of recording transactions: Results of the CPI are announced to the public on the 3rd of the month at 10:00 with a news bulletin. 

Revision is not foreseen in 2020.

 Seasonal adjustment: Data are not seasonally adjusted.