Reference metadata describe statistical concepts and methodologies used for the collection and generation of data. They provide information on data quality and, since they are strongly content-oriented, assist users in interpreting the data. Reference metadata, unlike structural metadata, can be decoupled from the data.
See the Annex for the National questionnaires, both English and Serbian versions
The data source is the Time Use Survey (TUS). Time Use Survey measures the amount of time people spend doing various activities, such as paid work, taking care of household and family members, personal care, social life, travelling and free-time activities. The survey assumes interviewing households and persons aged 15 years or over and filling in questionnaires by interviewers. Time Use Survey is used to support gender equality policies, family, social, transport and cultural policies and to measure the value of household production, as well as for international comparisons.
Time Use Survey was implemented for the second time in the Republic of Serbia. According to the Official Statistics Plan for 2020, which announces the implementation of the SORS surveys, the Time Use Survey was supposed to begin in early April 2020 and the fieldwork was supposed to last for a year. However, immediately after the training for interviewers and controllers in March 2020, a state of emergency was introduced in the Republic of Serbia as a form of population protection in the fight against the infectious disease COVID-19. During the spring and summer of 2020, the SORS did not conduct any survey. Therefore the implementation of the TUS was postponed for a year. It lasted one year, from 5 April 2021 to 4 April 2022.
The population that was interviewed is the population aged 15 years or over, that has been residing or working in the Republic of Serbia for a year or more. The persons who have been living abroad for more than a year, persons living in collective households, as well as the staff of Serbia’s diplomatic and consular representations were not included in this survey.
A stratified two-stage sample of clusters was used. The units of the first stage are enumeration areas (clusters of households) and the units of the second stage are households. The sample size contains 2 340 households in 234 enumeration areas; namely, in each enumeration area 10 households were selected.
The instruments used in the survey are fully compliant with the Harmonized European Time Use Survey – HETUS. The Household questionnaire contains the list of all household members, it is used to collect data for the household and each member. The questions from the Household questionnaire were answered by the household member aged 15 years or over that is best familiar with the situation in the household. The questions from the Individual questionnaire were answered by the household members aged 15 years or over. The individual questionnaire consists of questions related to education and educational attainment, working status, occupation, health etc. The Individual questionnaire also included national-specific questions related to the stress before and during the pandemic, questions related to decision-making at the household level and how the income earned by the interviewed person is spent (questions Z1, Z2, D1 and D2).
The statistical domains were ensured on a micro level, just as recommended. The third survey instrument is the diary that household members aged 15 years or over filled in for specified days and dates as assigned to them. Household members were informed in advance about the dates and days for filling out the diary. It is expected that the members of one household, aged 15 years or over, would fill two diaries for the same days in the week, namely one diary for a working day (Monday to Friday) and another one for a weekend day (Saturday or Sunday).
The main classification system used in the Harmonized European Time Use Surveys (HETUS) is the Activity Coding List – ACL. ACL contains the codes of activities to be assigned to the main and parallel activities, that an interviewed person usually carries out in a day. The diary, i.e. 24 hours in a day, is divided into 144 intervals of 10 minutes each (time slots) and the codes of activities are assigned to each 10-minute interval.
Other classifications used are ‘Location’ where the time is spent (including the modes of transport) and ‘With whom’ the time is spent. The classification system used for the Location/Transport mode is the same as in the Harmonized European Time Use Surveys (HETUS).
The classifications NACE rev2 (EU statistical classification of economic activities) and ISCO-08 (classification of occupations) are used in TUS. The economic activity and occupation refer to the main job that the interviewed person stated to carry out and were coded according to the defined classifications of activities and occupations.
3.2.1. Versions and breakdowns (level) of the classifications used for the data collection
Acronym
Version
Level
NACE (Statistical Classification of Economic Activities in the European Community - Eurostat 2007)
Rev. 2
ISCO (3 digits of the International Standard Classification of Occupations - ILO 2008)
08
ISCED (International Standard Classification of Education - UNESCO)
2011
NUTS (Nomenclature of territorial units for statistics, level NUTS2 - Eurostat)
2021
Other
3.2.2. Deviations from ESS or international standards
Four new (national) activity codes, not present in HETUS ACL, were added:
Drinking coffee (code 022, added to 021 in microdata sent to Eurostat)
Smoking (code 023, added to 531 in microdata sent to Eurostat)
Child care provided by another member of the household, not a parent, older sister or brother (code 388, added to 381 in microdata sent to Eurostat) and
Watching the TV Puzzle (Serbian Latin: TV Slagalica; English: TV Puzzle) (code 822, added to 821 in microdata sent to Eurostat).
3.3. Coverage - sector
Households, living conditions, time use, working time, travels, free time.
3.4. Statistical concepts and definitions
In the Time Use Survey, three basic measures (indicators) are used to present the data, namely: average time spent doing a certain activity, the proportion of ‘doers’ in a certain activity and the average time for ‘doers’ in a certain activity.
The average time spent doing certain activities refers to all persons in the survey. It is calculated by dividing the total amount of time spent on an activity by the number of persons (diaries) in the survey.
The proportion of ‘doers’ in certain activities presents the participation rate of the interviewed persons, who spent some time doing the activity in a day. It is the proportion of the individuals that spent some time doing the activity. It is calculated when the number of “doers” for certain activities is divided by the number of persons (diaries) in the survey.
The proportion of ‘doers’ in certain activities presents the average time for “doers” and refers only to persons doing the activity. It is calculated by dividing the total time spent on the activity by the number of persons (diaries) who spent some time doing the activity.
TUS provides information on the main activity and on the secondary (parallel) activity, that the respondents are doing during the day. Respondents decide which is the main and which is the secondary activity, for each 10-minute time period or longer. Respondents also report in their diary if they used a computer, internet or some smart device when doing some activity. The above indicators refer to the main activity only.
3.5. Statistical unit
Persons, households and time; household, persons aged 15 years or over; diary, 10 minutes interval.
The same definition for the household, as recommended by HETUS methodology, is used in the Serbia TUS. The collective households were not sampled.
3.6. Statistical population
The target population is represented by private, non-institutional households and persons aged 15 years or over, in the territory of the Republic of Serbia without Region Kosovo and Metohija, which are the usual population. Persons living in collective households and diplomatic and consular staff are excluded.
3.6.1. Main characteristics of the survey population
The population covered by the survey was limited to households living in enumeration areas with a minimum of 20 households recorded in the time of 2011 Census of Population and Dwellings.
3.7. Reference area
The territory of the Republic of Serbia without Region Kosovo and Metohija, and enumeration areas where, in the time of 2011 Census, a minimum of 20 households were recorded. The population covered by the survey was reduced by 1.5% when related to the target population.
3.8. Coverage - Time
Covered 52 weeks, from 5 April 2021 to 4 April 2022.
3.9. Base period
Not applicable.
In Time Use Surveys three basic measures are used: the average time spent doing a certain activity, the proportion of ‘doers’ in a certain activity and the average time for ‘doers’ in a certain activity. The average time is presented in minutes or in the format hours:minutes. The proportion is given in percentage.
For definitions see also above in section 3.4 Statistical concepts and definitions.
TUS is envisaged to cover one year, i.e. all 365 days. In the case of the Republic of Serbia, the survey was implemented from 5 April 2021 to 4 April 2022. All respondents aged 15 years or over were asked to fill-in a diary for two days, one for a working day/weekday (Monday - Friday) and one for a weekend day (Saturday - Sunday).
6.1. Institutional Mandate - legal acts and other agreements
The Time Use Survey is carried out on a ten-year basis following the Gentlemen's agreement between participating countries and Eurostat.
The Official Statistics Law (Official Gazette of RS, number 104/2009) defines the legal frame for disseminating data and information on official statistics, as well as for the organization of the system of official statistics in the Republic of Serbia.
6.1.1. At European level
The current round of the harmonised European time use survey (HETUS) data collection has been carried out in the spirit of multi-national and multi-agency cooperation across Europe, in the form of a ’gentlemen's agreement’.
6.1.2. At National level
The Official Statistics Law (Official Gazette of RS, number 104/2009) defines the legal frame for the dissemination of data and information on official statistics, as well as the organization of the system of official statistics in the Republic of Serbia. The Official Statistics Law, along with the five-year Programme of official statistics for the period 2019 – 2023 and the Annual implementation plan stipulates the legal and institutional programme frame for the collection, production and dissemination of data and information and organization of the system of official statistics.
In addition, according to Article 18(2) Official Statistics Law (Official Gazette of RS, number 104/09) and Article 42(1), Law on Government (Official Gazette of RS, number 55/05, 71/05 – rev, 101/07, 65/08 and 16/11), every year the Government is envisaged to pass the regulation adopting Annual plan of official statistics. Time Use Survey 2020 wave is part of the Annual plan of official statistics for 2021.
6.2. Institutional Mandate - data sharing
The Statistical Office of the Republic of Serbia (SORS) is the only agency within the national statistical system responsible for the production of time-use data.
The Statistical Office of the Republic of Serbia (SORS), as the responsible producer of official statistics, provides use of anonymized microdata according to the submitted request form, available at SORS website (see link in annex). The request can be submitted by:
Authorized scientific – research organizations (institutes, faculties, universities and centres of extreme values);
Institutions conducting separate projects financed by national or international research programs.
Universities and certified research centres can also apply to Eurostat, for access to TUS Serbia microdata for scientific purposes.
The protection of individual data is an issue of utmost importance. The survey results are published in an aggregated form, thereby in compliance with the provisions of the Official Statistics Law, and fully ensuring the confidentiality of individual data of households and persons. The microdata provided to be used for scientific research purposes contain aggregated data on respondents, to prevent the identification of interviewed households and individuals.
Definitions are available in the following documents:
Official Statistics Law (Official Gazette of RS, number 104/09, Art. 44 - 49);
Programme of official statistics for the period from 2019 to 2023, June 2015;
Programme of strategic development of official statistics and modernization of the Statistical Office of the Republic of Serbia, May 2017;
Official Statistics Law is also available in English version at the SORS website.
Article 44 – Data confidentiality Article 45 – Prevented identification of reporting units Article 46 – Confidential data protection Article 47 – Restricted access to confidential data Article 48 – Provided individual data without identificators Article 49 – Dissemination of small aggregates data
8.1. Release calendar
TheRelease Calendar is publicly available on the SORS website on 1 December of the current year for the forthcoming year.
The daily deadline for all SORS releases is 12.00.
All deviations from the fixed deadlines shall be advised in advance and explained in the Release Calendar.
According to the Official Statistics Law (Official Gazette of RS, number 104/09) and the European Statistics Code of Practice, all users shall receive equal treatment. Time Use Survey data and publications are released on the SORS website and are made available to all users at the same time.
The daily deadline for all SORS releases is 12.00. All deviations from the dates fixed in the published Release Calendar shall be advised in advance and explained.
There is a possibility to provide special data processing on users' requests.
The TUS data is disseminated on a ten-year basis. The TUS 2020 wave data findings were published in December 2024.
The TUS 2020 data were published in the publication Time Use in the Republic of Serbia, 2021/2022, on the website of the Statistical Office of the Republic of Serbia in March 2025. The Serbian version was released in December 2024.
The TUS 2020 wave data and variables for Serbia sent to Eurostat are prepared in line with the Data Delivery Guidelines, for the Harmonized European Time Use Survey Round 2020.
10.6.1. Metadata completeness - rate
Not requested.
10.7. Quality management - documentation
The data are followed by the report on quality.
11.1. Quality assurance
With full observance of the European statistical system and following the Quality policy, the Statistical Office of the Republic of Serbia strives to achieve full compliance of its statistical production with the European Statistics Code of Practice (CoP). The system of quality management of SORS is fully compliant with the statistical requirements since it implements the systemic upgrading of the quality of statistical processes, final results and data, as well as the services rendered to users. For further information on the quality system implemented in the Statistical Office of the Republic of Serbia please see the Declaration on quality.
For TUS Serbia we applied FCT – Field Check Tables. They were generated regularly during the fieldwork, according to the data collected and compiled during the fieldwork. FCT tables were used to monitor the response rate for households, persons and accomplishment of diaries, for enumeration areas and interviewers. FCT was used to monitor the interviewers’ fieldwork and to make the necessary interventions in the field.
The special focus was to ensure the quality of coding activities. We created and ran a set of SPSS scripts to find the inconsistencies in the activity coding and to apply the changes in datasets.
The time-use statistics are produced and are completely compliant and harmonized with the methodology and recommendations of Eurostat. TUS, just like any other sample-based survey, is subject to the usual types of errors related to random sampling. To avoid the release of unreliable data, the publishing of estimates based on a sample size below 25 observations is avoided, or the flag ‘u’ is used.
12.1. Relevance - User Needs
Time use data are compiled under the requirements of the gender organisations of the Republic of Serbia. The legal provision concerning the conduct of TUS is also made an integral part of the Gender Equality Law (2021).
The time use data is intended for policymakers and researchers, as a reply to the following questions: How much time do women and men spend doing paid, and how much doing unpaid work? Are housework activities equally divided between women and men? How much time do people spend commuting to work and from work? How much time do people spend on personal care activities? How much time do people spend in activities related to volunteering? What activities do people do in their free time?
12.2. Relevance - User Satisfaction
The very fact that the Time Use Survey is included in the Law on Gender Equality is proof of the increased interest in data on how the population of the Republic of Serbia spend their time.
The user satisfaction survey is conducted every two years and in 2025 we will also include time-use survey questions.
12.3. Completeness
As for the microdata sent to Eurostat, the data compiled in the TUS survey contain all variables stipulated by Eurostat, except the level of urbanization. In the Republic of Serbia, administrative distribution to ‘urban’ and ‘other’ settlements is used.
12.3.1. Data completeness - rate
Not requested.
13.1. Accuracy - overall
One of the error sources concerns household and individual refusal to respond or the impossibility of finding a respondent. The effects of absence and nonresponse were diminished by adjusting nonresponse as regards households and individuals/persons. The sample structure of persons corresponds to the structure of population according to the demographic estimates for the year 2021, because the calibration was carried out according to the territory on the level NUTS 2, by sex and age classes. The frame for sample selection was based on the 2011 Census of Population, Households and Dwellings. The coverage errors (e.g. in cases of new and demolished buildings) could not be evaluated since the frame for sample selection was not updated.
13.2. Sampling error
Information is provided in the following sub-concepts 13.2.1-13.2.3.
13.2.1. Sampling error - indicators
See below.
13.2.2. Sampling error - proportion and confidence interval
Parameter of interest (p̂)
(Population (aged 15 and over) spending daily on average more than 10 % of time working in paid work)
Number of respondents - n
(Number of individuals completed at least 1 diary day)
(unweighted)
Estimated proportion - p̂ (weighted)
Standard error for p̂
95% confidence interval for p̂
lower border
upper border
All
3802
0.375163
0.008789
0.357844
0.392483
Women
1994
0.298588
0.009834
0.279210
0.317966
Men
1808
0.457393
0.012668
0.432431
0.482356
13.2.3. Sampling error - method used for the variance (SE) estimation
Sampling errors are calculated using the SPSS software module for complex samples.
13.3. Non-sampling error
See below.
13.3.1. Coverage error
The sampling frame used for the selection of the sampling units was based on the 2011 Census and was not updated. Over and under coverage occurred. Over coverage is calculated from the survey. Under coverage is unknown.
13.3.1.1. Over-coverage - rate
Over-coverage - rate = 4.83%
13.3.1.2. Common units - proportion
Not applicable.
13.3.2. Measurement error
Not applicable.
13.3.2.1. Questionnaire design and testing
The questionnaires used in the TUS 2020 wave in Serbia are standard questionnaires defined in HETUS: Household Questionnaire,Individual Questionnaire for person aged 15 years or over (with additional national questions, see below) and Diary for person 15 years and over. See the annexes in the concept 3.1 Data description for the attached questionnaires.
There are a few additional national questions added in the Individual Questionnaire for person aged 15 years or over, in relation to HETUS. They are:
Z 1. When we talk about stress, would you describe your life as:
Possible answers are: 1. Not stressful at all, 2. Not so stressful, 3. A bit stressful, 4. Pretty stressful and 5. Extremely stressful
Z 2. How would you describe your life now compared to before the pandemic? Would you say that it is:
Possible answers are: 1. Much more stressful, 2. A little more stressful, 3. Stressed like before the pandemic, 4. A little less stressful and 5. Much less stressful
The questions Z 1. and Z 2. were added after I 30 question.
Additionally, the new section MAKING DECISIONS, with two questions D 1. and D 2. was added after question I 32. These two questions were tested and used in Serbia in TUS 2010 wave. Please see the 3.1 Data description annex, in Individual Questionnaire, for contents of these questions.
13.3.2.2. Interviewer training
25 interviewers were engaged in the survey in total. They are not employed by the Statistical Office of the Republic of Serbia.
The interviewers were selected in cooperation with fieldwork controllers. The request was to select experienced interviewers, those with experience in previous TUS rounds and other surveys, such as SILC, LFS, etc.
The training itself was held in two days. The themes covered during the first training day were:
introduction and basic information about the survey - survey instruments and participants;
List of households: how to find households, how to access and interview them;
Household Questionnaire: demonstration of filling-in by the CAPI method (IST application);
Individual questionnaire for persons aged 15 and over: demonstration of filling-in by the PAPI method;
Individual questionnaire for persons aged 15 and over: demonstration of filling-in by the CAPI method (IST application) and sending data to the central computer, and
EXERCISE: Practical work, filling in household and individual questionnaires by the CAPI method and sending data to the central computer.
The themes covered during the second training day were:
Diary: demonstration of filling-in, first by PAPI and then by the CAPI method (web application),
EXERCISE: Practical work, filling in the diary (CAPI method)
Finally, the last section of the training was devoted to the organization of fieldwork. The organization was presented and discussed in detail with the interviewers and heads of teams.
13.3.2.3. Proxy interview rates
Not applicable.
13.3.3. Non response error
See below.
13.3.3.1. Unit non-response - rate
Please see the Annex 1, sheet "13.3.3.1.Unit non-response".
13.3.3.1.1. Reasons for non-response
Overall, 73.5% of all households were interviewed successfully.
Household interviewing - reasons for non-response
Refusal of cooperation, 13.6%
Household not found, 8% and
Other (abandoned, demolished house, etc.), 4.8%
The reasons for the refusal of cooperation are:
The household does not want to be disturbed, 60.7%
Poor communication or language problems, 1.6%
Illness or death in the family, 16% and
Lack of time, 21.7%
In the interviewed households, 94.6% of all persons aged 15 or over were interviewed.
The reasons for the refusal of cooperation of individuals aged 15 years or over are:
Person will be absent next three weeks, 26.5%
No one of the household members provided data, 7.3%
Person refuses to be interviewed, 35.9% and
Other reasons, 30.3%
13.3.3.1.2. Number of households in the gross sample according to the final results of the survey
Please see the Annex 1, sheet "13.3.3.1.2. Gross sample".
13.3.3.1.3. Characteristics of non-respondents
In the interviewed households, a total of 94.6% of all persons aged 15 years or older were interviewed successfully.
Among individuals not interviewed, the breakdown is:
1.4%, will be absent in the next three weeks;
0.4%, no one of the household members provided data;
2%, person refuses to be interviewed and
1.6% stated some other reasons.
As for the interviewed persons, the lowest response is among young persons aged 15-29 years (90.2%), then those aged 30-64 years (94.5%). The highest is among individuals aged 65 years or more (96.9%).
If observing at the level of regions (NUTS2 level), the lowest response in interviewing individuals is in the Belgrade region (79.4%). For other regions, response is 99.5.% for Region Vojvodina or higher.
When looking at filled-in diaries, the lowest percentage of filled-in diaries is in Belgrade region (63.5%). For other regions, the percentage of filled-in diaries is higher than 90%, being the highest in Region Južna and Istočna Srbija (97.3%).
13.3.3.1.4. Efforts to reduce non-response
In order to improve the response rate, the official letter was sent in advance to the sampled households. The aim of the letter is to inform the households that they are being selected to be interviewed. The letter contained information about the survey, and its goals and also stressed the information that all collected data would stay strictly confidential and will be used for statistical purposes only.
Because the survey was conducted in the time of COVID pandemic, interviewers also offered respondents interviews by phone or Internet. Among persons interviewed, 19.3% were interviewed by phone or using Internet.
13.3.3.1.5. Adjustment of weights in order to reduce non-response
Calibration procedure
13.3.3.1.6. Other comments regarding non-response errors
Not applicable.
13.3.3.1.7. Replacement of non-responding households (substitution)
Substitution rate
Rate
i.e. Number of substitute households successfully interviewed/Achieved sample size
Not applicable.
13.3.3.1.8. Description of the substitution
Not applicable.
13.3.3.1.9. Qualitative assessment of the bias associated with unit non-response
Not applicable.
13.3.3.2. Item non-response - rate
The variables that are most subject to item nonresponse are those that refer to income of the household, i.e. questions H 6. and H 7.
Please see the details in the following sub-concept.
13.3.3.2.1. Variables most subject to item non-response
The variables that are most subject to item nonresponse are in the Household Questionnaire:
Question H 6.: 18.1% of respondents refused to give direct information about overall household income and even 40.4% stated that they didn't know it.
Question H 7.: 11.9% of respondents refused to give information about the overall household income range and 12% stated don't know it.
13.3.4. Processing error
Not applicable.
13.3.5. Model assumption error
Not applicable.
14.1. Timeliness
Data was collected in 2021/2022. The preliminary results were disseminated in January 2023. The TUS microdata was delivered to Eurostat in December 2022 and approved on 24 June 2024.
14.1.1. Time lag - first result
Nine months, May 2022 (finished fieldwork) - January 2023 (published preliminary results).
20 months, May 2022 (finished fieldwork) - December 2024 (complete final results).
The final microdata were sent and approved by Eurostat on 24 June 2024.
14.2. Punctuality
Information is provided in the following sub-concept.
14.2.1. Punctuality - delivery and publication
Eight months: May 2023 - December 2023, between the end of the fieldwork and sending the data to Eurostat.
15.1. Comparability - geographical
At the intra-national level, we use the type of settlement instead of the degree of urbanisation. The data can be produced and disseminated till the NUTS2 level.
The data enables comparison with other countries since it is collected and fully compliant with the HETUS methodology.
15.1.1. Asymmetry for mirror flow statistics - coefficient
Not applicable.
15.2. Comparability - over time
The data from Time Use Surveys conducted in Serbia in 2010/2011 and 2021/2022 are comparable.
15.2.1. Length of comparable time series
Not requested.
15.3. Coherence - cross domain
No other sources of TUS data are available.
15.3.1. Coherence - sub annual and annual statistics
Not applicable.
15.3.2. Coherence - National Accounts
Not requested.
15.4. Coherence - internal
Statistics are consistent within a given data set.
Time Use Survey 2021/2022 was fully funded out of the state budget: remuneration for interviewers, transport costs, payments for coders of TUS diaries and other costs.
The sample size in TUS 2021/2022 was the same as in 2010, that is 2340 households. The total cost in TUS 2020 was € 57 874.
16.1. Costs of the survey
Time Use Survey 2021/2022 was fully funded out of the Budget of the Republic of Serbia: remuneration for interviewers, transport costs, payments for coders of TUS diaries and other costs.
The sample size in TUS 2021/2022 was the same as in 2010, that is 2340 households. The total cost in TUS 2020 amounted to RSD 6 757 387 = € 57 874 (exchange rate as of 17 May 2022).
16.2. Average time used for answering the survey questionnaires (in minutes)
Average lasting of household interviewing – 21.3 minutes
Average lasting of individual interviewing – 11.9 minutes
16.3. Average time used to fill in the diary (in minutes)
This information is not collected in the diary.
16.4. Measures taken to reduce the cost and burden of the survey
The letter to the sampled households was sent in advance, with basic information about the survey goals.
The number of visits of interviewers to the households was optimised to reduce transport costs.
17.1. Data revision - policy
The General Revision policy is available on SORS website, in the Policy section.
17.2. Data revision - practice
If a minor error has been detected, the author has to initiate and control the correction, as soon as possible, in all forms of dissemination. Users should be notified about these corrections.
Serious errors detected immediately after data release should be corrected with no delay or as soon as possible. The users who have received the data in question should be informed about the presence of errors and upcoming revisions. Incorrect data should be removed from the database and the reason for that communicated to the public. If the incorrect data appears in a published text, a note about the error should be added to the beginning of the text or the text should be entirely removed from the public. Users should be informed about the upcoming revision using the same information means as for releases. Furthermore, the date of the non-scheduled revision should be added to the revision calendar.
SORS has established a Procedure for the correction of errors in released data and information, which lays down all the activities related to non-scheduled revisions, as well as the channels of informing users. This procedure defines the following:
detection of errors;
determining error types;
correction of minor errors in statistics/information;
correction of serious errors in statistics/information:
correction of serious errors in printed publications;
correction of serious errors in electronic editions (publications, statistical releases and press releases);
correction of serious errors in databases;
correction of serious errors in website content;
exception from activities in removing serious errors;
error correction in the calendar of publications;
form for serious mistakes correction - a standardized form for the reporting of detected serious errors in the published statistical data/ information.
17.2.1. Data revision - average size
Not applicable.
18.1. Source data
Information on sampling design, sampling frame and size is available under the full metadata concepts 18.1.1 - 18.1.3.
18.1.1. Sampling frame
Type
Name of data source used for building the sampling frame
Population census
Yes: The frame for sample selection is based on the 2011 Census on Population, Households and Dwellings in the Republic of Serbia
Population register
No
Household register
No
Dwelling register
No
List of phone numbers
No
Postcode address file
Yes
Another survey sample
No
Other
No
18.1.2. Sampling design of the survey
See below.
18.1.2.1. Sampling design(s)
Type
Description of Sampling Design
Simple random sampling
Not applicable
Systematic sampling
Not applicable
Stratified sampling
Not applicable
Cluster sampling
Not applicable
Other
Two-stage stratified cluster sample approach was used. The first stage units were enumeration areas and the second stage units were households.
18.1.2.2. Ultimate sampling unit(s)
Households
18.1.2.3. Oversampling of specific populations
Not applicable.
18.1.2.4. Assumptions used for determining the sample size
The sample size is determined based on available financial resources.
18.1.3. Sample size
Sample size
Number of households (HHs)
Gross sample size
Formula: initial sample size = responding units + non-responding units (these two groups make up the group of eligible units) + units with unknown eligibility (e.g. because they are not able to be reached/ contacted), + ineligible units.
2340
Number of eligible units
Formula: net sample size = Gross sample size - units with unknown eligibility – ineligible units
2039
Achieved sample size = Total number of households which were successfully surveyed (interviews+diaries)
1513
18.2. Frequency of data collection
It is generally recommended that the TUS data should be collected once in 5-10 years.
Time Use Survey was conducted for three times in the Republic of Serbia, i.e. in 2010/11 and 2021/22 as full-scale TUS and in 2015 as Light Time Use Survey, LTUS.
The surveys from 2010/11 and 2021/22 were carried out using classic diaries, that had been left to household members to fill in the information on what activities they did during the diary day.
In 2015 the survey was implemented in four months, which represented four seasons of the year. The paper diary offered predefined activities, where respondents marked the time when the activities were carried out. Also, the respondents could fill in diaries via the web application or Android application.
18.3. Data collection
See below.
18.3.1. Data collection method used
Mixed mode
18.3.2. Mode(s) and instruments for data collection: household and individual questionnaire
Interview
Specify Yes or No if used
% of completed household interviews
Paper-assisted personal interview (PAPI)
Yes
10.1%
Computer-assisted personal interview (CAPI)
Yes
65%
Computer-assisted telephone interview (CATI)
Yes
17.8%
Computer-assisted web-interview (CAWI)
No
0.0
Smart mode (e.g. smartphone app)
No
0.0
Other (e.g. administrative data). Combined method
Yes
7.1%
18.3.3. Mode(s) and instruments for data collection: time use diary
Diary
Specify Yes or No if used
% of completed diaries
Paper diary
Yes
100%
Computer-based non online diary
No
0.0
Online web diary
No
0.0
Mobile-based diaries (Smartphone apps, etc.)
No
0.0
18.3.4. Variables completed from an external source
No one variable was completed from the external source.
18.4. Data validation
The SORS IT staff created the application, IST program (desktop application), for filling the household questionnaire data and the web application for entering information from the filled diaries. In both applications logic control for checking entry was integrated. The data validation was carried out in compliance with the criteria set by Eurostat.
The controllers' tasks were to organize and monitor the fieldwork of interviewers, assist interviewers in establishing contacts with respondents, solve potential problems in field operations while filling questionnaires, and check other accompanying forms of the survey (TUS, travel costs, etc.). In addition, the controllers coded two boxes: the economic activity of the local unit where the person is employed and the occupation of the interviewed person. Both questions are found in the individual questionnaire.
Data checking and validation
Diary coding was carried out in succession and after the accomplished diary entry by interviewers. The first coding stage assumed the automatic coding of activities. It was done in succession and on a monthly basis. The material contained all activities entered for the previous month.
The TUS 2021 automatic coding was based on TUS 2010 coded activities, with added activities, to achieve better automatic recognition of the entered activities. The TUS dictionary contains almost 10,000 activities with codes. For this purpose, the ACL with examples was taken from the HETUS guide, with added national codes and examples.
Upon the accomplishment of the automatic coding, the coded material was additionally coded (for the activities that were not automatically coded), controlled and corrected by five coders. As the coding was ongoing, the work on the TUS activities coding was improved in two ways: the dictionary contents were several times supplemented and upgraded. During the coding phase, the coders learned by heart the codes and became more efficient in completing their assigned portions of material.
The average time of diary coding could not be calculated because of several different coding stages that were not carried out by the coders only.
Coding quality control – The diaries were coded by the persons engaged on a contract basis (out of SORS). The training for five coders was conducted at the beginning of the process of material coding and was organized online. During the one-year work on coding the TUS diaries activities, regular consultations of TUS methodologists and coders were carried out both at online meetings and by mail.
Overall, the coding was implemented successively for somewhat less than a year, namely after entering diaries by interviewers on a monthly basis.
SPSS programs are used to check possible inconsistencies in coded activities for later correction.
18.5. Data compilation
Data compilation includes information related to the imputation rate, methods applied to correct for item non-response, if applicable, and information on the calculation of weighting factors and weight adjustments. For more information, see concepts 18.5.1 - 18.5.3.
18.5.1. Imputation - rate
Not applicable.
18.5.2. Method applied to correct for 'item non-response'
Methods
Specify Yes or No if used
Simple imputation (deterministic) method
No
Simple imputation (stochastic) method
No
Multiple imputation approach
No
Other
No
18.5.3. Calculation of weighting factors and weight adjustments
The base weight (design weight) is calculated as a reciprocal value of the product of the probabilities of selection at every stage in each sampling stratum. The second component in the calculation of the sample weight is a non-response adjustment at the household level (factor inversely proportional to the response rate within each homogeneous group). Starting with the design weight corrected for nonresponse, separately, two final weights were calculated:
calibration was included for the calculation of a household and person in the case of a household questionnaire and individual questionnaire (same weight for household and persons from the household);
post-stratification according to gender, age class and territory was used for dairy weights. First, an adjustment factor was included for non-response on keeping the diary for weekday and weekend days. Then post-stratification was applied, which means that the sum of individual weights for weekdays corresponded to the population total and the sum of individual weights for weekend-day corresponded to the population total. Then weights were multiplied by 5/7 for a weekday and 2/7 for a weekend day. Then these weights were used for all tables related to the time use.
18.6. Adjustment
Not applicable.
18.6.1. Seasonal adjustment
Not applicable.
Number of filled-in diaries: 7115 (87.3%).
Number of not filled-in diaries: 1031 (12.7%).
Two diaries were filled in by 3313 persons (81.3%).
One diary was filled in by 489 persons (12%).
271 interviewed persons (6.7%) didn't fill in any diary.
Five individuals reported having the usual weekly working hours in the main job over 80 hours.
See the Annex for the National questionnaires, both English and Serbian versions
The data source is the Time Use Survey (TUS). Time Use Survey measures the amount of time people spend doing various activities, such as paid work, taking care of household and family members, personal care, social life, travelling and free-time activities. The survey assumes interviewing households and persons aged 15 years or over and filling in questionnaires by interviewers. Time Use Survey is used to support gender equality policies, family, social, transport and cultural policies and to measure the value of household production, as well as for international comparisons.
Time Use Survey was implemented for the second time in the Republic of Serbia. According to the Official Statistics Plan for 2020, which announces the implementation of the SORS surveys, the Time Use Survey was supposed to begin in early April 2020 and the fieldwork was supposed to last for a year. However, immediately after the training for interviewers and controllers in March 2020, a state of emergency was introduced in the Republic of Serbia as a form of population protection in the fight against the infectious disease COVID-19. During the spring and summer of 2020, the SORS did not conduct any survey. Therefore the implementation of the TUS was postponed for a year. It lasted one year, from 5 April 2021 to 4 April 2022.
The population that was interviewed is the population aged 15 years or over, that has been residing or working in the Republic of Serbia for a year or more. The persons who have been living abroad for more than a year, persons living in collective households, as well as the staff of Serbia’s diplomatic and consular representations were not included in this survey.
A stratified two-stage sample of clusters was used. The units of the first stage are enumeration areas (clusters of households) and the units of the second stage are households. The sample size contains 2 340 households in 234 enumeration areas; namely, in each enumeration area 10 households were selected.
The instruments used in the survey are fully compliant with the Harmonized European Time Use Survey – HETUS. The Household questionnaire contains the list of all household members, it is used to collect data for the household and each member. The questions from the Household questionnaire were answered by the household member aged 15 years or over that is best familiar with the situation in the household. The questions from the Individual questionnaire were answered by the household members aged 15 years or over. The individual questionnaire consists of questions related to education and educational attainment, working status, occupation, health etc. The Individual questionnaire also included national-specific questions related to the stress before and during the pandemic, questions related to decision-making at the household level and how the income earned by the interviewed person is spent (questions Z1, Z2, D1 and D2).
The statistical domains were ensured on a micro level, just as recommended. The third survey instrument is the diary that household members aged 15 years or over filled in for specified days and dates as assigned to them. Household members were informed in advance about the dates and days for filling out the diary. It is expected that the members of one household, aged 15 years or over, would fill two diaries for the same days in the week, namely one diary for a working day (Monday to Friday) and another one for a weekend day (Saturday or Sunday).
In the Time Use Survey, three basic measures (indicators) are used to present the data, namely: average time spent doing a certain activity, the proportion of ‘doers’ in a certain activity and the average time for ‘doers’ in a certain activity.
The average time spent doing certain activities refers to all persons in the survey. It is calculated by dividing the total amount of time spent on an activity by the number of persons (diaries) in the survey.
The proportion of ‘doers’ in certain activities presents the participation rate of the interviewed persons, who spent some time doing the activity in a day. It is the proportion of the individuals that spent some time doing the activity. It is calculated when the number of “doers” for certain activities is divided by the number of persons (diaries) in the survey.
The proportion of ‘doers’ in certain activities presents the average time for “doers” and refers only to persons doing the activity. It is calculated by dividing the total time spent on the activity by the number of persons (diaries) who spent some time doing the activity.
TUS provides information on the main activity and on the secondary (parallel) activity, that the respondents are doing during the day. Respondents decide which is the main and which is the secondary activity, for each 10-minute time period or longer. Respondents also report in their diary if they used a computer, internet or some smart device when doing some activity. The above indicators refer to the main activity only.
Persons, households and time; household, persons aged 15 years or over; diary, 10 minutes interval.
The same definition for the household, as recommended by HETUS methodology, is used in the Serbia TUS. The collective households were not sampled.
The target population is represented by private, non-institutional households and persons aged 15 years or over, in the territory of the Republic of Serbia without Region Kosovo and Metohija, which are the usual population. Persons living in collective households and diplomatic and consular staff are excluded.
The territory of the Republic of Serbia without Region Kosovo and Metohija, and enumeration areas where, in the time of 2011 Census, a minimum of 20 households were recorded. The population covered by the survey was reduced by 1.5% when related to the target population.
TUS is envisaged to cover one year, i.e. all 365 days. In the case of the Republic of Serbia, the survey was implemented from 5 April 2021 to 4 April 2022. All respondents aged 15 years or over were asked to fill-in a diary for two days, one for a working day/weekday (Monday - Friday) and one for a weekend day (Saturday - Sunday).
One of the error sources concerns household and individual refusal to respond or the impossibility of finding a respondent. The effects of absence and nonresponse were diminished by adjusting nonresponse as regards households and individuals/persons. The sample structure of persons corresponds to the structure of population according to the demographic estimates for the year 2021, because the calibration was carried out according to the territory on the level NUTS 2, by sex and age classes. The frame for sample selection was based on the 2011 Census of Population, Households and Dwellings. The coverage errors (e.g. in cases of new and demolished buildings) could not be evaluated since the frame for sample selection was not updated.
In Time Use Surveys three basic measures are used: the average time spent doing a certain activity, the proportion of ‘doers’ in a certain activity and the average time for ‘doers’ in a certain activity. The average time is presented in minutes or in the format hours:minutes. The proportion is given in percentage.
For definitions see also above in section 3.4 Statistical concepts and definitions.
Data compilation includes information related to the imputation rate, methods applied to correct for item non-response, if applicable, and information on the calculation of weighting factors and weight adjustments. For more information, see concepts 18.5.1 - 18.5.3.
Information on sampling design, sampling frame and size is available under the full metadata concepts 18.1.1 - 18.1.3.
The TUS data is disseminated on a ten-year basis. The TUS 2020 wave data findings were published in December 2024.
Data was collected in 2021/2022. The preliminary results were disseminated in January 2023. The TUS microdata was delivered to Eurostat in December 2022 and approved on 24 June 2024.
At the intra-national level, we use the type of settlement instead of the degree of urbanisation. The data can be produced and disseminated till the NUTS2 level.
The data enables comparison with other countries since it is collected and fully compliant with the HETUS methodology.
The data from Time Use Surveys conducted in Serbia in 2010/2011 and 2021/2022 are comparable.
