ANNUAL QUALITY REPORT

Transcription

1 REPUBLIKA SLOVENIJA ANNUAL QUALITY REPORT FOR THE SURVEY ANNUAL REPORT ON RETAIL TRADE, WHOLESALE AND COMISSION TRADE (TRG/L) FOR 2012 Prepared by: Dominika Lunder, Rudi Seljak Date: November /8

2 Table of contents 0 Methodological explanations about survey Relevance Rate of Missing Statistics Accuracy Sampling Errors Sampling Error Non-sampling Errors Non-response errors Unit Non-response Rate Variable Non-response Rate Rate of unsuccessful linking of the variable Imputation rate Coverage Errors Over-coverage Errors Under-coverage Errors Measurement Errors Editing rate Timeliness and Punctuality Timeliness Timeliness of the First Release Timeliness of Final Results Punctuality Punctuality of the First Release Accessibility and Clarity Accessibility Channels used for the dissemination of the results Rate of Used Channels Clarity Results presented Level (Detail) of Presentation Comparability Comparability over Time Length of Comparable Time Series Breaks in Time Series Geographical comparability Comparability with Other Members of the European Statistical System Seasonal Adjustment Coherence Coherence between provisional and final data Coherence between provisional and final data Coherence with the Results of the Reference Survey Reference Survey Coherence with Reference Data Costs and burdens Survey Costs of the Office Costs and Burden of Reporting Units /8

3 0 Methodological explanations about survey The purpose of the survey The purpose of the annual report on retail trade, wholesale and commission trade (TRG/L) is annual statistical monitoring of data on turnover from sale of goods and material by commodity groups and by kind of buyers in retail and wholesale and on turnover in commission trade. Legal basis The survey is conducted on the basis of the National Statistics Act (OJ RS, NO. 45/95 and No. 9/01) and the annual programme of statistical surveys. Observation Unit Observation unit is every business entity or its part (enterprise, company, business unit, entrepreneur) that performs trade activity, irrespective of its main activity. Coverage and Classifications The sampling frame of the TRG/L survey includes all legal forms of enterprises that perform one of the trade activities in section G of the Standard Classification of Activities (NACE Rev. 2) as their main activity: - 45 Wholesale and retail trade and repair of motor vehicles and motorcycles, - 46 Wholesale, except of motor vehicles and motorcycles, - 47 Retail trade, except of motor vehicles and motorcycles. Enterprises whose main activity is not in section G of the Standard Classification of Activities (NACE Rev. 2) but which had some turnover from sale of goods and material as a result of their trade activity are also covered. From the sampling frame of enterprises, approximately 3,600 enterprises are included in the survey. We used a stratified, single-stage sample, which was stratified with proportional allocation by groups of activities and size of the enterprise defined with annual turnover and number of employees. Key variables Key variables are: - Turnover in retail trade, - Turnover in wholesale, - Turnover in commission trade. Key statistics Key statistics are: turnover from sale of goods and material in retail trade, wholesale and in commission trade. Turnover is summed up by kind of buyers and by commodity groups. Questionnaire The questionnaire is available on this website (only in Slovene): Methodological explanations Methodological explanations are available on this website: 3/8

4 1 Relevance 1.1 Rate of Missing Statistics The rate of missing statistics is 0. 2 Accuracy 2.1 Sampling Errors Sampling Error Table 2.1: Estimated value and coefficient of variation for key statistics, 2012 Estimated value (mio EUR) Coefficient of variation (in %) Turnover in retail trade ,58 Turnover in wholesale ,55 Turnover in commission trade (on domestic market) , Non-sampling Errors Non-response errors Unit Non-response Rate Table 2.2: Unit Non-response Rate, 2012 Number of eligible units Number of non-responses 776 Non-response rate 24,5 % Variable Non-response Rate In collecting and editing the data it was established that units that completed the questionnaire answered all questions. There was no variable non-response Rate of unsuccessful linking of the variable Because this is a fieldwork survey and is not conducted on the basis of data from administrative sources, the rate of unsuccessful linking of the variable is equal to the variable non-response rate, i.e Imputation rate There is no imputation of missing data, because missing values of key variables are dealt with in the editing phase Coverage Errors Over-coverage Errors Table 2.3: Over-coverage Rate, 2012 Number of Sample Units Number of Non-eligible Units 294 4/8

5 Over-coverage Rate 8,5 % Comments: Non-eligible units are: - Units that stopped operating, - Dormant units, - Units that are not part of the target population and - Other units which are non-eligible for other reasons Under-coverage Errors Some units of the population are not part of the sampling frame, so we have under-coverage errors. The threshold for entering the sampling frame is: - enterprise had turnover from the sale of goods (based on final accounts) ) of at least EUR in 2011 or - enterprise had turnover from the sale of goods (based on VAT data) of at least EUR in 2012 or - enterprise has at least 5 employees Measurement Errors Editing rate Table 2.4: Editing rate by key variables, 2012 Turnover in retail trade 2,0 % Turnover in wholesale 1,6 % Turnover in commission trade (on domestic market) 0,5 % 3 Timeliness and Punctuality 3.1 Timeliness Timeliness of the First Release Table 3.1: Timeliness of the First Release Reference period Year 2012 Date of publishing Time lag (T + ) T+8 months Timeliness of Final Results Data published in the First Release are also final results. Timeliness of final results is therefore the same as timeliness of first release. 3.2 Punctuality Punctuality of the First Release Table 3.2: Punctuality of the First Release Reference period Year 2012 Announced date Publishing date /8

6 Difference (days) 0 days 4 Accessibility and Clarity 4.1 Accessibility Channels used for the dissemination of the results Table 4.1: Dissemination channels No.: Channels Used 1 Website YES 2 Databases accessible through the Internet (SI-STAT) YES Publication in interactive web tools (Interactive statistical atlas 3 of Slovenia, Thematic cartography, etc.) NO 4 Ad hoc prepared data for users according to their specification YES 5 Data available through telephone answering machine NO 6 General printed publications YES 7 Thematic printed publications YES 8 Databases (e.g. Social Science Data Archives ) NO 9 Statistically protected micro data NO 10 Early access to data according to the standard protocol NO Rate of Used Channels The rate of used channels was 50%. 4.2 Clarity Results presented Results include data on turnover from sale of goods (without VAT) in retail trade, in wholesale and in commission trade. Data on retail and wholesale are divided by kind of buyers and by commodity groups Level (Detail) of Presentation Results for retail sale and wholesale are published at the lowest level of commodity groups (as stated in the questionnaire). Retail trade is divided into 71 commodity groups and wholesale into 46 commodity groups. Commission trade is not divided into subgroups. 5 Comparability 5.1 Comparability over Time Length of Comparable Time Series Time series of annual data is available for the period after January Due to changes in the survey methodology in 2008 we cannot assure the comparability of data for past time series. 6/8

7 Breaks in Time Series In 2008 the survey was redesigned in terms of content. According to the former methodology the whole turnover of enterprise was attributed to the main (the one with which the enterprise created the most turnover) trade activity of the enterprise. Now in each activity there is only turnover actually made with this activity. Revision of the survey included revision of sampling methodology. Analysis showed that the former sampling method was not appropriate for areas that are included in this survey; revision was also needed due to the transition to the new classification of activity (SKD 2008) and due to the inclusion of new trade activities that used to be excluded because of single monitoring of results. According to the needs of main users we prepared more detailed breakdown of commodity groups. New division of commodity groups is more detailed than before and more coordinated with CPA (Classification of Products by Activity) and COICOP (Classification by Individual Consumption) classifications. The tables that related to determination of commodity activity were excluded from the questionnaire. We also excluded all questions that did not gather enough quality results (for example, number of stores, number of employees). Due to changes in the methodology the data since 2008 are not comparable with the time series before that year. 5.2 Geographical comparability Comparability with Other Members of the European Statistical System The data are not comparable with other members of the European Statistical System because the survey methodology was not determined by the EU. 5.3 Seasonal Adjustment Methods of seasonal adjustment are not used in this survey. 6 Coherence 6.1 Coherence between provisional and final data Coherence between provisional and final data We do not publish provisional data. We only publish final data. 6.2 Coherence with the Results of the Reference Survey Reference Survey Source for comparison: A monthly statistical survey about trends of turnover in retail trade, sale and maintenance of motor vehicles and motorcycles (TRG/M) and a monthly statistical survey about trends in wholesale (TRG-D/M). Compared statistic: annual index of turnover Coherence with Reference Data Table 6.1: A comparison of annual indices of turnover from the surveys TRG/M and TRG/L 7/8

8 Turnover index 2012/2011 TRG/L Monthly survey Difference Wholesale 98,5 100,6-2,1 Retail trade 98,7 102,9-4,2 Comments: In monthly surveys on trade activity we monitor current monthly changes of turnover in retail trade, except of motor vehicles and motorcycles (SKD 47),in wholesale trade, except of motor vehicles and motorcycles (SKD 46) and in wholesale and retail trade and repair of motor vehicles and motorcycles (SKD 45) of the enterprises whose principal activity is classified into distributive trade. Data on turnover refer to economic operations of the whole enterprise, including eventual secondary activity not related to distributive trade. In annual survey we collect data on turnover of enterprises that perform trade activity, irrespective of their main activity. We collect only the turnover which is a result of their trade activity; that is turnover derived from sale of goods and material. Data for the monthly survey are partly gathered from administrative sources (they are taken from the database with information about VAT). In the annual survey we use only data on turnover that we collect with the field questionnaires. 7 Costs and burdens 7.1 Survey Costs of the Office Table 7.1: Survey costs at the Statistical Office, 2012 Number of working hours spent Number of reporting units that should complete the questionnaire Periodicity annual Number of questionnaires per year (total) Costs and Burden of Reporting Units Table 7.2: Burden and costs of the reporting units, 2012 Number of reporting units that submitted their data Annual number of questionnaires per unit 1 Time spent on completing one questionnaire (hours) 0,5 Total time spent (hours) /8