|Unit||Index 2015=100, NSA|
|Adjustments||Not Seasonally Adjusted|
The source defines the Consumer Price Index (CPI) as measurment of changes in the prices of goods and services acquired, used or paid over time by a reference population (private households) for final consumption purposes.
The CPI acts as a measure of inflation and can guarantee the value of recurrent payments in escalator clauses for contractual relationships, for example wages and salaries in collective agreements. It also acts as a comparison of the price movements within a certain country between different economy sectors and as a bias for deflating the national accounts data and other statistical series.
A representative basket consisting of about 917 different items is the basis of the CPI calculation. Each month, about 37070 prices are gathered within a fixed panel of outlets in nine geographical cities and towns throughout the country (Zagreb, Slavonski Brod, Osijek, Sisak, Rijeka, Pula, Split, Dubrovnik and Varaždin)
The weights used for calculating the CPI show the relative importance of the sampled goods or services in resident households within the domestic territory's total consumption. The Croatian Bureau of Statistics regularly conducts a Household Budget Survey which is a primary sources for calculating the weights used in the CPI.
The classification of products used in the CPI is based on the Classification of Individual Consumption by Purpose (COICOP).
Calculating CPI starts with the computation of the elementary aggregate indices. These indicies are calculated as a ratio of geometric means of the current and the reference period of all the prices of products within the elementary aggregate.
Next, the consumer price indices are compiled using the formula for the weighted arithmetic mean of the indices at the lower aggregation levels.
Since January 2015, the compilation of the CPIs has been based on the weights derived from the annual average household expenditures from the 2011 Household Budget Survey, recalculated into the prices in December 2014.
Indices were recalculated from base year 2001 to base year 2005, from base year 2005 to base year 2010, and from base year 2010 to base year 2015. In addition, according to Eurostat’s recommendations, water supply was excluded from Services category and included into Goods category. Indices for goods and services were recalculated back to January 2005. Thus, the index for "Total" is greater than both the index for "Goods" and "Services" for the dates July 2003, August 2003, July 2005, and August 2005.
For more information see the bottom of the PDF for the reference period. For example: http://www.dzs.hr/Hrv_Eng/publication/2015/13-01-01_08_2015.htm