quarterly gross domestic product
QUARTERLY GROSS DOMESTIC PRODUCT
IN THE REPUBLIC OF SERBIA
C O N T E N T S
2.1. Gross domestic product - production approach, at constant prices ......................... 4
2.1.3. Indicators and calculation methods, by sections of the Classification of
2.2. Gross domestic product - production approach, at current prices ......................... 10
3.3. Non-profit institutions serving households (NPISH) final consumption expenditure
3.4.7. Government final consumption expenditure at current and constant prices ... 15
3.5.5. Gross fixed capital formation at current and constant prices .......................... 17
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Preface
The Statistical Office of the Republic of Serbia (SORS) communicates the results of the quarterly calculations of the gross domestic product (GDP) in the Republic of Serbia at current and constant prices, derived according to production and expenditure approach.
Methodological framework is based on the principles and definitions of the System of
National Accounts 1993 (SNA 93), European System of Accounts 1995 (ESA 95),
International Monetary Fund manual (Quarterly National Accounts Manual) and Eurostat manuals (Handbook on Price and Volume Measures in National Accounts and Handbook on Quarterly National Accounts).
Data sources for the quarterly gross domestic product calculation are various and cover a range of economic and financial indicators. Data are obtained from the surveys from the statistical system, designed for monitoring specific areas or features of the economy
(production, prices, employment, and so on), as well as from administrative sources.
The statistical methods used for quarterly GDP calculations could be classified into two groups: direct and indirect.
Direct methods are based on quarterly statistical surveys with complete coverage or sample based; these surveys are established for the purpose of quarterly calculations.
Indirect methods could be classified as: methods based on the disaggregating of available annual to quarterly data and extrapolation of the current year quarterly values, using statistical models and respective quarterly indicators; methods based on the disaggregating of available annual to quarterly data and extrapolation of the current year quarterly values, using statistical models, however without respective quarterly indicators.
Indirect methods are more frequently used. Selected is the method that minimizes the error of the quarterly values of the current year estimates, so that the preliminary annual estimates, obtained as the sum of quarterly amounts are as close as possible to the final annual data. The choice also depends on the availability of data for the current period.
1. Characteristics of quarterly calculations
1.1. Characteristics of quarterly constant prices calculations
The calculation of GDP at previous year prices means that the previous year is taken as a base year. In that way, the structural changes in relative prices that occurred between two consecutive years in an economy are taken into account. In GDP constant prices
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calculations according to production approach, weights in the base year are determined by the share of GVA of each division of the Classification of Activities, FISIM and net taxes in the GDP.
The measuring of the real GDP movement in year t relative to year t-1 requires that GDP in both years is valued at the same prices. This means that we compare GDP in year t at constant prices, i.e. previous year prices, with GDP of year t-1 at current prices. Time series calculated at previous year prices could not be used for real growth rate calculations since data are not comparable (each year is valued at previous year prices).
To obtain comparable series, applied is the method of chain-linking, where indicators in the form of indices are chain-linked and reduced to the selected reference year. The choice of the reference year does not affect the growth rate changes, as they always remain the same, regardless the fact which year is selected as reference year. According to Eurostat recommendations, 2010 has been currently used as the reference year.
The frequency of quarterly calculations anticipates that one of three techniques is selected to obtain chain-linked volume measures: annual, one-quarter and over the year overlap.
Statistics of the most countries apply the annual overlap technique, which means that previous year average prices are used as a link for chaining current year quarters and provides the consistency of quarterly chain-linked series with independently obtained annual chain-linked series.
Additivity means that the aggregate could be obtained by summing all its components.
The fixed base method of constant price estimation ensures that GDP elements are valued at the same prices and by converting them to monetary terms provided are values that could be added together to obtain aggregates. With the transition to the calculations at previous year prices additivity still exists, but there are no comparable data in the series, because the GDP elements for each year are valued at previous year prices. To obtain comparability, series of GDP elements are chain-linked and reduced to the selected reference year. As a result of converting chain-linked volume measures to monetary terms, using the reference year prices, the non-additivity problem appears since aggregates could not be obtained by summing its elements. Additivity exists only in the reference year and the year after, but just for an annual level.
It should be noted that chain-linked volume measures converted to monetary terms should not be referred to as "constant prices". Constant prices are calculations with fixed base, or "moving" base year (previous year prices). Chain-linked volume measures are just an instrument that solves the problem of comparability and should be called "chainlinked volume measures, reference xxxx year”.
1.2. Benchmarking
According to Eurostat recommendations, ECOTRIM, version 1.01 is applied for the reconciliation of quarterly and annual calculations. The statistical model developed by
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Chow and Lin (1971) is used for disaggregation of the available annual vales to quarterly data and extrapolation of the current year quarterly values. It is based on the estimation of econometric relationships which ensures perfect coherence with the annual series and provides optimal extrapolation for the current year. Therefore, in principle, quarterly accounts have the same coverage and valuation quality as annual accounts to which they are constrained. This program disaggregates the available annual vales to quarterly data and extrapolates the current year quarterly values by using respective indicators. This ensures that the sum of quarterly values is equal to the value obtained by annual calculations, i.e. that quarterly growth rates of indicators are maintained as much as possible.
1.3. Seasonal adjustment
Seasonal adjustment is a process of time series decomposition, which removes seasonal effects on time series behavior. According to the Eurostat recommendations, software
DEMETRA, procedure TRAMO/SEATS, indirect method is used.
2. Gross domestic product - production approach
Gross domestic product, derived according to production approach, is the total of value added of all divisions of the Classification of Activities (CA), minus FISIM, plus net taxes.
2.1. Gross domestic product - production approach, at constant prices
Gross domestic product at constant prices, derived according to production approach, is the total of value added of all divisions of the Classification of Activities (CA), minus
FISIM, plus net taxes at constant prices.
Calculations at constant prices have been implemented for the level of divisions of the
Classification of Activities (2010).
2.1.1. Data sources
The main data sources used for the calculations are:
Statistical surveys: monthly data on industrial production; monthly data on physical volume of forest exploitation; monthly data on sales and purchase value of agricultural products; monthly data on tourists; monthly data on transport and telecommunications; monthly data on employees; monthly data on prices; monthly data on catering turnover value;
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monthly unit value indices for import; monthly and quarterly data on trade turnover value; quarterly data on value of construction works done and hours worked; annual data on agricultural production.
Administrative and other sources: monthly data on budgetary income and expenditure (taxes on products and services, customs duties, subsidies); monthly data on deposits and credits at commercial banks; quarterly data on insurance premiums.
2.1.2. The calculation method
GDP calculation is performed in two stages: calculations at previous year prices and chain-linking.
In the first stage, calculations at previous year prices are carried out:
1.
Calculation of GVA at previous year prices for 88 divisions of the Classification of
Activities, FISIM, taxes on products and imports (customs duties) and subsidies on products, using respective indicators and weights;
2.
Calculation of GVA at previous year prices for 21 CA sections, by summing up GVA at previous year prices of divisions classified in respective section; net taxes at previous year prices calculation by summing up taxes on products and imports
(customs duties) and subtracting subsidies on products at previous year prices;
3.
Calculation of GVA of all activities at previous year prices by summing up GVA of all sections at previous year prices;
4.
Calculation of GVA at previous year prices by subtracting FISIM from GVA of all activities at previous year prices;
5.
Calculation of GDP at previous year prices by summing up GVA and net taxes at previous year prices.
In the second stage, chain-linked volume measures are calculated:
1.
Series of chain-linked indices are independently calculated and reduced to the reference year average for CA 88 divisions, 21 sections, FISIM, taxes on products and imports (customs duties), subsidies on products, net taxes, GVA of all activities,
GVA and GDP;
2.
Monetary terms for each of the above-mentioned categories are obtained by multiplying chain-linked indices with the corresponding nominal value of the reference year (2010). The values obtained in this way are referred to as ”chain-linked volume measures, reference year 2010”.
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2.1.3. Indicators and calculation methods, by sections of the Classification of Activities
2.1.3.1. Agriculture, forestry and fishing (section А)
Crop and animal production, hunting and related service activities (division 01)
Indicators: annual index of physical volume of agricultural production (net); monthly data on sales and purchase value of agricultural products, at current prices; monthly producer price indices of agricultural products.
Annual index of agricultural production (net) is used for calculations of annual GVA of agricultural production at constant prices by extrapolating GVA of the base year.
Distribution of annual GVA over quarters is carried out according to monthly dynamics of the sales and purchase of agricultural products at constant prices and fixed proportions of production costs, by quarters (20%, 25%, 30%, 25%).
Forestry and logging (division 02)
Indicator – monthly index of physical volume of forest exploitation.
Applied is the extrapolation of GVA of the base year with the index of physical volume of forest exploitation.
Fishing and aquaculture (division 03)
Indicator – monthly index of number of employees.
Applied is the extrapolation of GVA of the base year with the index of number of employees.
2.1.3.2. Mining and quarrying (section B), Manufacturing (section C), Electricity, gas and steam supply (section D)
Indicator – monthly index of physical volume of industrial production.
Applied is the extrapolation of GVA of the base year of each division classified within one of these three sections with respective index of physical volume of industrial production.
2.1.3.3. Water supply, sewerage, waste management and remediation activities
(section Е)
Indicator – monthly index of number of employees.
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Applied is the extrapolation of GVA of the base year of each division classified within this section with the respective index of number of employees.
2.1.3.4. Construction (section F)
Indicators: quarterly value of construction works done at current prices; quarterly index of hours worked; monthly producer price index of construction materials.
Applied is the extrapolation of GVA of the base year with the composite index, derived from the index of value of construction works done at constant prices and the index of hours worked.
2.1.3.5. Wholesale and retail trade; repair of motor vehicles and motorcycles
(section G)
Indicators: monthly and quarterly data on retail trade turnover value, at current prices; quarterly data on wholesale trade turnover value, at current prices; quarterly data on trade of motor vehicles turnover value, at current prices; monthly consumer price index; monthly producer price index of industrial products; monthly index of import unit values.
Applied is the extrapolation of GVA of the base year with index of turnover value, at constant prices.
2.1.3.6. Transportation and storage (section H)
Indicators: quarterly physical volume indices of transportation services; monthly index of number of employees.
Applied is the extrapolation of GVA of the base year of each division classified within section H (except 52 – Warehousing and support activities for transportation) with respective physical volume index of transport services. For division 52 applied is the extrapolation of GVA of the base year with the index of number of employees.
2.1.3.7. Accommodation and food service activities (section I)
Indicators: monthly data on catering turnover value, at current prices; monthly consumer price index; monthly index of number of overnight stays.
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For Accommodation (division 55), applied is the extrapolation of GVA of the base year with the index of the number of overnight stays.
For Food and beverage service activities (division 56), applied is the extrapolation of
GVA of the base year with the index of catering turnover value, at constant prices.
2.1.3.8. Information and communication (section J)
Indicators: monthly physical volume indices of telecommunication services; monthly index of number of employees.
Applied is the extrapolation of GVA of the base year of each division classified within section J (except 61 – Telecommunications) with the respective index of number of employees. For division 61, applied is the extrapolation of GVA of the base year with physical volume index of telecommunication services.
2.1.3.9. Financial and insurance activities (section K)
Indicators: monthly stocks of deposits and credits at commercial banks, at current prices; quarterly data on insurance premiums, at current prices; monthly consumer price index; monthly index of number of employees.
For Financial service activities, except insurance and pension funding (division 64), applied is the extrapolation of GVA of the base year with composite index, derived from the index of average stocks of deposits and credits at constant prices and the index of the number of employees.
For Insurance, reinsurance and pension funding, except compulsory social security
(division 65), applied is the extrapolation of GVA of the base year with the index of insurance premiums at constant prices.
For Activities auxiliary to financial services and insurance activities (division 66), applied is the extrapolation of GVA of the base year with the index of the number of employees.
2.1.3.10. Real estate activities (section L)
Indicators: annual data on imputed rents, at constant prices; quarterly data on GVA of all sections (except section L), at constant prices; monthly index of number of employees.
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For the part of the division 68 – Real estate activities, the calculation is carried out by disaggregating annual values of imputed rents at constant prices to quarterly, based on quarterly dynamics of the GVA sum of all sections, except section L.
For the rest of the division 68, in calculations applied is the extrapolation of GVA of the base year with the index of the number of employees.
2.1.3.11. Other services
Professional, scientific and technical activities (section М)
Administrative and support service activities (section N)
Public administration and defence; compulsory social security
(section O)
Education (section P)
Human health and social work activities (section Q)
Arts, entertainment and recreation (section R)
Other services activities (section S)
Activities of households as employers (section T)
Indicator – monthly index of number of employees.
In calculations applied is the extrapolation of GVA of the base year of all divisions classified within these sections with the respective index of number of employees.
2.1.3.12. FISIМ – Financial intermediation services indirectly measured
Indicators and the calculation method used for FISIM are the same as for the Financial service activities, except insurance and pension funding (division 64).
2.1.3.13. Taxes, customs duties and subsidies
Data on taxes on products are calculated by extrapolation of the value of taxes on products in the base year with the indices derived from quarterly dynamics of the GVA sum of all sections, at constant prices.
Customs duties are calculated by applying the extrapolation of the value of customs duties in the base year with the index of wholesale trade turnover value, at constant prices.
Subsidies on products are calculated by extrapolation of the base year value of subsidies on products with the composite index, which is derived as the weighted average of the index of physical volume of agricultural production and the index of physical volume of services in railway and urban transport. As weights, the structure of subsidies assigned from the budget for these activities is used.
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Net taxes are derived as the sum of taxes on products and imports, minus subsidies on products.
2.2. Gross domestic product - production approach, at current prices
Gross domestic product at current prices measured by production approach represents the total of GVA of all economic activities, minus FISIM and plus net taxes on products, at current prices.
Calculations at current prices have been implemented for the level of divisions of the
Classification of Activities (2010).
2.2.1. Data sources
Statistical surveys: monthly data on prices; monthly and quarterly data on turnover values of trade and catering; quarterly data from the survey “Quarterly Structural Survey on Enterprises“; quarterly data on value of construction works done; annual GVA data at current and constant prices.
Administrative and other sources: monthly data on budgetary income and expenditure (taxes on products and services, customs duties, subsidies); monthly data on deposits and credits at commercial banks; quarterly data on insurance premiums.
2.2.2. Calculation method
Calculations for the level of 88 divisions of the Classification of Activities have been conducted applying the following methods: inflation of quarterly values at constant prices using respective price indices, for those divisions where prices are available; disaggregation of annual to quarterly data, using quarterly data at current prices as indicators, for those divisions where quarterly data at current prices are available; inflation of quarterly values at constant prices with quarterly deflators, derived by disaggregating annual implicit deflators of the GVA of divisions, for the divisions where adequate indicators are not available.
Calculations for the level of 21 sections of the Classification of Activities have been implemented by summing GVA of divisions classified within respective section.
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3. Gross domestic product - expenditure approach
The expenditure-based GDP comprises final consumption expenditure by households, non-profit institutions serving households and government, gross fixed capital formation, acquisitions less disposals of valuables, changes in inventories and net exports of goods and services.
The current price calculations are carried out for all expenditure categories:
Household final consumption expenditure (HFCE) – at the three-digit level of the
Classification of Individual Consumption According to Purpose (COICOP), residents in the rest of the world and non-residents on the Serbian territory;
Non-profit institution serving households final consumption expenditure (NPISH)
- total;
Government final consumption expenditure (GFCE) – partly according to the
Classification of the Functions of the Government (COFOG) – individual and collective government consumption;
Gross fixed capital formation (GFCF) - by technical structure;
Acquisitions less disposals of valuables - total;
Changes in inventories;
Exports and imports – distinction in goods and services.
3.1. Data sources
Statistical surveys: monthly data on catering turnover value; monthly data on tourists; monthly data on exports and imports of goods; monthly data on employees and wages and salaries; monthly data on prices; monthly data on industrial production; monthly unit value indices for export and import; monthly and quarterly data on trade turnover value; quarterly data on value of construction works done; quarterly data from Household Budget Survey; quarterly data from the survey “Quarterly Structural Survey on Enterprises“.
Administrative and other sources: monthly data on budgetary revenues and expenditure; monthly data on exports and imports of services; monthly data on exchange rates.
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3.2. Household final consumption expenditure
The calculation is done according to the national concept as it includes residents expenditure abroad and excludes non-residents expenditure on the territory of the
Republic of Serbia.
Household final consumption expenditure (HFCE) has been calculated for the group level
(3-digit level) of the Classification of Individual Consumption According to Purpose
(COICOP), residents in the rest of the world and non-residents on the Serbian territory.
One of the data sources used to estimate HFCE is the quarterly Household Budget Survey
(all the purchases of goods and services that people need for daily living – food, clothing, consumer durable goods, rent, transport, personal services, etc.). The other data sources, like trade, tourism, catering, transport statistics and data from the survey “Quarterly
Structural Survey on Enterprises“, have been used as well.
The current prices estimates for all categories of household final consumption are obtained by disaggregating annual to quarterly data, using quarterly indicators at current prices.
The current prices estimates are deflated with appropriate consumer price indices. The resulting chain linked series with reference 2010 year are benchmarked and converted to previous year prices.
The series at previous year prices for the 3-digit COICOP level, residents in the rest of the world and non-residents on the Serbian territory are summed up to derive total household final consumption expenditure at previous year prices. This aggregate is chainlinked to obtain total HFCE value with reference 2010 year.
3.3. Non-profit institutions serving households (NPISH) final consumption expenditure
Non-profit institutions serving households final consumption expenditure has small share in Serbian GDP, so estimates at current prices are obtained by disaggregating available annual to quarterly current price data and extrapolation of the current year quarterly values, using statistical models.
The current prices estimates are deflated with consumer price index. The resulting chain linked series with reference 2010 year are benchmarked and converted to previous year prices.
3.4. Government final consumption expenditure
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The final consumption expenditure of general government is estimated using input cost method. Calculations are done for collective and individual government consumption separately.
3.4.1. Compensation of the employees
The compensation of the employees at current prices are obtained by disaggregating annual to quarterly data, using quarterly data on compensation of the employees at current prices as indicators. Indicator for individual consumption is number of employees multiplied with average gross earnings in sections P (Education) and Q (Human health and social work activities) of the Classification of Activities. Budgetary data on compensation of the employees from the Ministry of Finance and Economy are used as indicator for total government consumption. Indicator for collective consumption is obtained as difference between total and individual consumption.
The compensations of the employees at constant prices are obtained by the extrapolation method, using the number of employees. Number of employees in section O (Public administration and defense; compulsory social security) of the Classification of Activities is used as indicator for collective consumption and number of employees in sections P and Q of the Classification of Activities is used as indicator for individual consumption.
The resulting chain linked series with reference 2010 year are benchmarked and converted to previous year prices.
3.4.2. Intermediate consumption
Intermediate consumption at current prices is obtained by disaggregating annual to quarterly data, using quarterly data on government intermediate consumption from the
Ministry of Finance and Economy as indicators. The split on collective and individual consumption was carried out using the annual shares of these categories in total intermediate consumption.
The current prices estimates are deflated with composite price index, derived by weighting the relevant price indices. As weights, the annual structures of government units’ intermediate consumption (19 categories of goods and services) are used. These data are taken from the annual financial statements for budgetary users. The resulting chain linked series with reference 2010 year are benchmarked and converted to previous year prices.
3.4.3. Consumption of fixed capital
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Consumption of fixed capital at current prices are obtained by disaggregating available annual to quarterly current price data and extrapolation of the current year quarterly values, using statistical models.
The current prices estimates are deflated with quarterly implicit deflator for gross fixed capital formation (the same one is used for individual and for collective consumption).
The resulting chain linked series with reference 2010 year are benchmarked and converted to previous year prices.
3.4.4. Other taxes on production
Other taxes on production at current prices are obtained by disaggregating available annual to quarterly current price data and extrapolation of the current year quarterly values, using statistical models.
The other taxes on production at constant prices are obtained by the extrapolation method, using the number of employees. Number of employees in section O of the
Classification of Activities is used as indicator for collective consumption and number of employees in sections P and Q of the Classification of Activities is used as indicator for individual consumption. The resulting chain linked series with reference 2010 year are benchmarked and converted to previous year prices.
3.4.5. Social transfers in kind
Social transfers in kind at current prices are obtained by disaggregating available annual to quarterly current price data and extrapolation of the current year quarterly values, using statistical models.
The current prices estimates are deflated with composite price index, derived by weighting the relevant consumer price indices. As weights, the annual shares of health and social protection in total social transfers in kind are used. The resulting chain linked series with reference 2010 year are benchmarked and converted to previous year prices.
3.4.6. Market output
Market output at current prices are obtained by disaggregating available annual to quarterly current price data and extrapolation of the current year quarterly values, using statistical models.
Market output at constant prices is obtained by the deflation method. For collective part of market output deflator is consumer price index for services. Individual part of market output at current prices is deflated with composite price index, derived by weighting the
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relevant consumer price indices. As weights, the annual shares of health, culture, education and social protection in total individual market output. The resulting chain linked series with reference 2010 year are benchmarked and converted to previous year prices.
3.4.7. Government final consumption expenditure at current and constant prices
Total GFCE at current prices is obtained by summing up the current values of compensation of the employees, intermediate consumption, consumption of fixed capital, other taxes on production and social transfers in kind and by subtracting market output.
Total GFCE at previous year prices is obtained by summing up compensation of employees, intermediate consumption, consumption of fixed capital, other taxes on production and social transfers in kind and by subtracting market output at previous year prices. Next, this aggregate is chain-linked to obtain total GFCE value with 2010 as reference year.
3.5. Gross fixed capital formation
Gross fixed capital formation calculations are done by technical structure of investments
– investments in construction works, investments in equipment (with a split on investments in domestic and imported equipment) and investments in other fixed assets.
3.5.1. Investments in construction works
Investments in construction works at current prices are obtained by disaggregating annual to quarterly data, using quarterly data on value of construction works done at current prices as indicators.
The current prices estimates are deflated with composite price index, derived by weighting the relevant producer price indices of industrial products for domestic market and index of average gross earnings in construction. Data from annual financial statements of construction enterprises are used as weights. The resulting chain linked series with reference 2010 year are benchmarked and converted to previous year prices.
3.5.2. Investments in domestic equipment
Investments in domestic equipment at current prices are obtained by disaggregating annual to quarterly data. As indicators, quarterly data at current prices on output value for divisions of the Classification of Activities which cover equipment production are used.
Quarterly output values at constant prices are calculated by extrapolating annual output data, using the industrial production indices. Constant price output values are then
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inflated with appropriate producer price indices of industrial products for domestic market.
The calculation of the quarterly investments in domestic equipment at constant prices is done by deflating the quarterly investments in domestic equipment at current prices. As deflator, weighted PPI is used. This index is obtained by weighting the appropriate producer price indices of industrial products, for relevant divisions of the Classification of Activities. Weights are determined by the annual share of output of each division in the sum of outputs of all divisions. The resulting chain linked series with reference 2010 year are benchmarked and converted to previous year prices.
3.5.3. Investments in imported equipment
Investments in imported equipment at current prices are obtained by disaggregating annual to quarterly data. As indicators, quarterly data at current prices on imports value for divisions of the Classification of Activities which cover equipment production are used.
The calculation of the quarterly investments in imported equipment at constant prices is done by deflating the quarterly investments in imported equipment at current prices.
Quarterly deflators are derived by disaggregating available annual deflators for imported equipment and extrapolation of the current year quarterly deflators, using statistical models. The resulting chain linked series with reference 2010 year are benchmarked and converted to previous year prices.
3.5.4. Investments in other fixed assets
For quarterly investments in other fixed assets at current prices, there is no appropriate indicator. Quarterly data for that category are obtained by disaggregating available annual to quarterly current price data and extrapolation of the current year quarterly values, using statistical models.
The calculation of the quarterly investments in other fixed assets at constant prices is done by deflating the current prices values. A weighted deflator is used. This deflator is obtained by weighting the appropriate producer price indices of industrial products for domestic market, consumer price indices and deflator which is used for investments in construction works. Annual weights are based on data from “Annual survey on investments in fixed assets”. The resulting chain linked series with reference 2010 year are benchmarked and converted to previous year prices.
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3.5.5. Gross fixed capital formation at current and constant prices
Total GFCF at current prices is obtained by summing up the current of investments in construction works, equipment and other fixed assets.
Total GFCF at previous year prices is obtained by summing up investments in construction works, equipment and other fixed assets at previous year prices. Next, this aggregate is chain-linked to obtain total GFCF value with reference 2010 year.
3.6. Acquisitions less disposals of valuables
Valuables has small share in Serbian GDP, so estimates at current prices are obtained by disaggregating available annual to quarterly current price data and extrapolation of the current year quarterly values, using statistical models.
The current prices estimates are deflated with consumer price index and previous year prices values are obtained. Since this aggregate can take negative as well as zero, these data cannot be chain linked.
3.7. Exports and imports
Quarterly exports and imports calculations are made separately for goods and services.
3.7.1. Exports and imports of goods
Exports and imports of goods at current prices are obtained by disaggregating annual to quarterly data, using quarterly data on value of exports and imports of goods at current prices as indicators.
The calculation of the exports and imports of goods at constant prices is done by deflating the current prices estimates. Quarterly deflators are derived by disaggregating available annual deflators for exports and imports of goods and extrapolating of the current year quarterly deflators, using statistical models. The resulting chain linked series with reference 2010 year are benchmarked and converted to previous year prices.
3.7.2. Exports and imports of services
Exports and imports of services at current prices is obtained by disaggregating annual to quarterly data, using quarterly data on value of exports and imports of services at current prices as indicators.
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The current prices estimates are deflated with total consumer price index. The resulting chain linked series with reference 2010 year are benchmarked and converted to previous year prices.
The quarterly import of services at constant prices is calculated by deflating the current prices values. A weighted deflator is used. This deflator is obtained by weighting the appropriate consumer price indices for 10 most important partners for import of services
(adjusted by changes of exchange rates of their currencies in Dinars). Weights are annual shares of imports of services from these countries in total import of services. The resulting chain linked series with reference 2010 year are benchmarked and converted to previous year prices.
3.7.3. Exports and imports at current and constant prices
By adding together exports i.e. imports of goods and exports i.e. imports of services, total exports i.e. imports, at current prices is obtained.
By adding together exports i.e. imports of goods and exports i.e. imports of services at constant prices, total exports, i.e. imports at constant prices is obtained. Next, these aggregates are chain-linked to obtain total exports, i.e. imports value with reference 2010 year.
3.8. Changes in inventories
In the statistical system of the Republic of Serbia still there is no reliable quarterly information at current prices which could be directly used as an indicator for the calculation of changes in inventories. Therefore, quarterly changes in inventories at current and previous year prices are obtained indirectly, as a residual item. Since the changes in inventories can take negative as well as zero, these data cannot be chain linked.
Calculations of GDP derived according to production and expenditure approach aren’t derived by using completely independent data sources, because the changes in inventories are calculated as residual. Consequently, quarterly changes in inventories may contain a statistical discrepancy, which could occur from the implementation of two completely independent calculations.
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