ANNUAL QUALITY REPORT

Transcription

1 REPUBLIC OF SLOVENIA ANNUAL QUALITY REPORT FOR THE SURVEY ANNUAL STATISTICAL SURVEY ON CONSTRUCTION (GRAD/L) FOR 212 Prepared by: Ajda Demšar Date: 2 th March 214 1/1

2 Table of Contents Methodological Explanations Relevance Rate of Unavailable Statistics Accuracy Sampling Errors Sampling Error Coverage Bias Coverage Bias Non-Sampling Errors Non-Response Errors Unit Nonresponse Rate Item Nonresponse Rate Imputation Rate Coverage Errors Overcoverage Rate Measurement Errors Editing Rate Rate of the Coherence of Data Sources Timeliness and Punctuality Timeliness Timeliness of the First Results Timeliness of Final Results Punctuality Punctuality of the First Results Accessibility and Clarity Accessibility Means Used for the Dissemination Rate of Means Used... Napaka! Zaznamek ni definiran. 4.2 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 Burden of Reporting Units /1

3 Methodological Explanations Brief Description of the Survey The annual survey on construction provides data on the value of construction put in place at the facility, regardless of whether these facilities are buildings or civil engineering works, and regardless of whether they are a new construction, reconstruction or maintenance work (investment or regular). It also provides information on the value of the organization that implements building projects, i.e. the service to mobilize financial, technical and physical resources for the construction of buildings (residential and non-residential) for subsequent sale. Since 28, in the observation are included - in line with the new version of the Standard Classification of Activities (NACE 28) - in addition to construction companies also companies dealing with the organization of building projects. Data on the value of construction put in place in buildings or civil engineering works, are presented by the Classification of Types of Constructions (CC-SI) ( Structural data on construction are important in the analysis of the construction activities and are necessary, among other tasks, also to calculate the gross domestic product (GDP). Legal Basis for the Survey The legal basis for the survey are the National Statistics Act (Official Journal of RS, No. 45/95 and 9/1) and the Annual Programme of Statistical Surveys (LPSR) for 213 (Official Journal of RS, No. 89/12). According to the stated legislation, provision of required data for the selected companies is mandatory. Observation Units The annual statistical survey on construction involves companies which implemented construction works in the observed year or organized the building projects (the service to mobilize financial, technical and physical resources for the construction of residential and non-residential buildings for subsequent sale) as a prime contractor or as a researcher. The main contractor reports the required data for potential subcontractors. Coverage In determining the list of observation units the method of threshold coverage is used. The survey sample includes all construction companies and companies dealing with the organization of building projects (section F - construction after SKD28, activities 41, 42 and 43), whose value of income for the taxation of value added tax in the reference year reaches a certain threshold (EUR 24, for 212), and the establishments engaged in construction activity or the organization of building projects which have at least 2 employees, and some other companies that perform construction work. The criterion of 74% coverage in the activities F Construction is taken into account. The GRAD/L survey for the reference year 212 included 886 respondents. Key Variables Key variables of the annual statistical survey on construction are: type of investor, type of works, type of construction according to the CC-SI classification, value of construction works put in place, value of organization of building projects. Key Statistics 3/1

4 Key statistics of the annual statistical survey on construction are: the value of construction put in place by the type of investor, the value of construction put in place by the type of works put in place, the value of construction put in place by the type of construction according to the CC-SI classification. Questionnaire The questionnaire is available on the website: Methodological Explanations The methodological explanations are available on the website: Value of construction put in place, Slovenia. 4/1

5 1 Relevance 1.1 Rate of Unavailable Statistics The present statistics on construction works is not part of any European regulation, but it is the LPSR that provides the basis for obtaining these data, primarily to meet the needs of public institutions and derivative statistics (GDP), as well as of operators in the industry. Therefore all the necessary statistics are calculated and these commitments are met in full, so the percentage of missing statistics equals zero (). 2 Accuracy 2.1 Sampling Errors Sampling Error The survey is carried out on the basis of a random sample, so the estimates do not contain the sampling error. 2.2 Coverage Bias Coverage Bias Explicit estimates of bias arising from the threshold of non-response and measurement errors can not be calculated because there are no adequate data from other sources. The sample does not cover the entire population, but it covers the population threshold. In view of the value of income for the taxation of value added tax in the reference year, 74% of the total population is captured. In 213, the revision of the survey was conducted in which we analysed nonresponse and prepared the procedures to minimize the bias due to non-response. Weighting was introduced. In this way the bias due to threshold coverage was reduced. 2.3 Non-Sampling Errors Non-Response Errors Unit Non-Response Rate Table 2.1: Unit non-response rate Reference period 212 Number of adequate units 77 Number of non-responses 193 Non-response rate Item Non-Response Rate There is no item non-response in the survey, as in the phase of collecting and compiling the data the questionnaires are checked as to whether they are completed in full and item non- 5/1

6 response is removed and examined. If not, the unit will be contacted by telephone or via e- mail and from it the missing information is obtained. In the phase of statistical processing thus all data of the units which report all the information required are entered and therefore there is no item non-response Imputation Rate In this survey we do not use the imputation of missing data. Thus, the imputation rate is zero () Coverage Errors Overcoverage Rate Table 2.2: Overcoverage Rate Reference year 212 Number of units in the Address book 886 Number of inadequate units 179 The rate of over-coverage (%) Measurement Errors Editing Rate In the material of the survey there were 675 units (the arrival rate is 76%). Upon acceptance of the material in Blaise there were 341 questionnaires with an error (5%). At the final handover of the material there were still 37 questionnaires with errors, which were examined. 39 reporting units were called, which is 5.8% in view of the questionnaires received Rate of the Coherence of Data Sources Sources for this survey do match. 3 Timeliness and Punctuality 3.1 Timeliness Timeliness of the First Results Table 3.1: Timeliness of the First Results Reference period 212 Date of publishing Time lag (days) T Timeliness of Final Results Data published in the First Release are also final data, so the timeliness of final data equals the timeliness of the First Release. 6/1

7 3.2 Punctuality Punctuality of the First Results Table 3.2: Punctuality of the First Results Reference period 212 Announced date Publishing date Difference In 213, we published the data for the reference year 212 again on the 11 th of November 213 in order to ensure appropriate comparability of data due to changes in the methodology (weighting). At the same time, we also published a series of weighted data for the reference years 21 and Accessibility and Clarity 4.1 Accessibility Means Used for the Dissemination Table 4.1: Means Used for Dissemination No.: Mean Used Website 1 (e.g. First Release, E-release) YES 2 Publication in the SI-STAT Data Portal YES Publication in the interactive web tools (e.g. Interactive Statistical Atlas of Slovenia, Thematic 3 Cartography) NO 4 Ad hoc prepared data for users according to their specification YES 5 Data available through telephone answering machine NO General printed publications 6 (e.g. Statistical Yearbook, Slovenia in Figures) YES Thematic printed publications 7 (e.g. Rapid Reports, Brochures) NO External databases 8 (e.g. Social Science Data Archives, Eurostat, OECD databases) NO 9 Statistically protected micro data NO 1 Preliminary access to data according to standard protocol NO To demonstrate the results 4 ways of expressing the results were used, which means that the rate of the methods used is 4%. 4.2 Clarity Results Presented All results are presented as absolute numbers. 7/1

8 4.2.2 Level (Detail) of Presentation Level data disemination are broken down by: Year The type of construction by CC-SI classification to the level of class Investor: Investor total Natural person Legal person: - Together - Public Administration - Utilities - Institutions and other non-profit organizations - Businesses and other organizations Type of construction activity: new construction extension reconstruction and conversion Investment maintenance regular maintenance work Standard Classification of Activities - SKD 28: SKD total F Construction other activities. 5 Comparability 5.1 Comparability over Time Length of Comparable Time Series After having improved the methodology of weighting, the data are published for 21, 211 and 212, i.e. for 3 years Breaks in Time Series There are no breaks in the time series. 5.2 Geographical Comparability Comparability with Other Members of the European Statistical System With the annual survey GRAD/L we collect data and provide information at the lower levels and for a bigger population than in the GRAD/M survey, particularly for national needs. The reference survey Monthly statistical survey on construction (GRAD/M) regulates the Regulation on short-term indicators (Council Regulation (EC) No 1165/98 concerning shortterm statistics), which is comparable to those in other Member States of the European Statistical System. Reference surveys GRAD/L and GRAD/M are comparable and consistent. 8/1

9 5.3 Seasonal Adjustment The seasonal adjustment procedures in this survey are not applied. 6 Coherence 6.1 Coherence between Provisional and Final Data Coherence between Provisional and Final Data Preliminary data are not disclosed. We publish only final data. 6.2 Coherence with the Results of the Reference Survey Reference Survey In the sample of the survey GRAD/M for the reference year 212 there are included all construction companies and companies dealing with the organization of building projects (Section F of the NACE 28, activities 41, 42 and 43), whose value of income for the taxation of value added tax in 211 reached at least EUR 1,2,, and the establishments engaged in construction activity or the organization of building projects that have at least 2 employees, and some other companies that perform construction work. In the address book for the reference year 212 there were included 183 units, of which 7 units were key respondents. The survey takes place monthly on the basis of the data obtained through questionnaires (postal survey) Coherence with Reference Data The survey GRAD/L for the reference year 212 covered 165 respondents that gave their responses also for the survey GRAD/M. Table 6.1 shows the indices of the reported values on construction works for the surveys GRAD/M and GRAD/L in 212, calculated to the average of 21. We can see that the data of both surveys differ at the level of total value of construction put in place for 212 by 3.3 index points, which can be attributed to differences in the sample of these two surveys. The survey GRAD/L covers 74% of the population while the sample for the survey GRAD/M is smaller. It covers 56% of the population. In establishing a sample for the survey GRAD/L we take into account also the observed changes and the known facts about business entities from the survey GRAD/M. The larger sample survey for the survey GRAD/L than that for the reference survey GRAD/M and the changes in business entities and discovered errors in the reporting of respondents in the survey GRAD/M can be attributed to the calculated difference between the two surveys at lower levels; at the level of buildings, the value of construction put in place in a part of the survey GRAD/L is higher by 15.4 index points and in civil engineering works it is lower by 4.4 index points. 9/1

10 Table 6.1: Coherence with Reference Data 212/21 GRAD/L GRAD/M DIFFERENCE IN INDEX POINTS CC_SI - TOTAL 68,8 65,5 3,3 1 BUILDINGS 68, 52,5 15,4 2 CIVIL INGINEERING WORKS 69,6 73,9-4,4 7 Costs and Burdens 7.1 Survey Costs of the Office The number of reporting units, which should complete the questionnaire, does not comprise the respondents, for whom it was revealed during the implementation of the survey that they were inadequate. Due to the comparability of the costs between EU Member States, the costs are expressed in working hours. To carry out the annual survey GRAD/L for 212, SURS spent 1,23 hours. Table 7.1: Survey costs at the Statistical Office Reference period 212 Number of working hours spent 1,23 Number of reporting units that had to fill in 77 questionnaires Survey period annual Number of questionnaires per year (total) Burden of Reporting Units The burden of reporting when fulfilling the Annual Questionnaire of Construction put in place (GRAD/L) is largely different. It depends on the number and fragmentation of construction projects to be implemented in the reference year, on the organization of the company (dislocated branch units and establishments), on the number of subcontractors and coperformers as well as the fact that a unit was for the first time included in the survey, or if it has already got accustomed to the survey in the previous years. The average time spent by the company to complete the questionnaire GRAD/L was estimated on a survey filled in by selected small, medium-size and large enterprises that were covered by the survey. The average time for a reporting unit to collect and enter the data that are required with the questionnaire GRAD/L is.5 hours per year. Table 7.2: Burden of the reporting units Reference period 212 Number of reporting units that submitted the data 675 Annual number of questionnaires per unit 1 Time spent to fill in a questionnaire (hours).5 Total time spent (hours) / 1