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.
Survey name(s) in the national language(s): Изследване на бюджета на времето
Survey name in English: Harmonised European Time Use Survey
Year(s) of (data collection) of the survey: 2022 - 2023
Link to the survey website (only available in Bulgarian)
National questionnair: please see the Annex (only available in Bulgarian)
Time use surveys (TUS) measure the amount of time people spend doing various activities, such as paid work, household and family care, personal care, voluntary work, social life, travel, and leisure activities. The survey consists of a household interview, a personal interview, a weekday diary and a weekend diary. Data are acquired by interviewing the sampled hoseholds and individuals directly and self-completion in the diary.
3.2.1. Versions and breakdowns (level) of the classifications used for the data collection
Acronym
Version
Level
NACE
NACE Rev.2
2-digit
ISCO
ISCO 08
2-digit
ISCED
ISCED 2011
1-digit
NUTS
NUTS 2023
2-digit
Other
3.2.2. Deviations from ESS or international standards
No deviations from ESS or international standards.
3.3. Coverage - sector
Not requested.
3.4. Statistical concepts and definitions
This domain provides population estimates for activities according to the HETUS-ACL for three main indicators:
Time spent: mean time spent on the activities by all individuals;
Participation time: mean time spent in the activities by those individuals who took part in the activity; and
Participation rate: the proportion of the individuals that spent some time doing the activities.
3.5. Statistical unit
The scope of the Time Use Surveys is the usual resident population of the country aged 10 and over and living in private households.
The observation units are person, household and time.
Definition of usual resident population "Usual residence" means the place where a person normally spends the daily period of rest, regardless of temporary absences for purposes of recreation, holidays, visits to friends and relatives, business, medical treatment or religious pilgrimage. The following persons alone shall be considered to be usual residents of a specific geographical area:
those who have lived in their place of usual residence for a continuous period of at least 12 months before the reference time; or
those who arrived in their place of usual residence during the 12 months before the reference time with the intention of staying there for at least one year.
Definition of private household "Private household" means a person living alone or a group of people who live together providing themselves with the essentials of living, being either:
A one-person household, i.e. a person who usually resides alone in a separate housing unit or who occupies, as a lodger, a separate room or rooms of a housing unit but does not join with any of the other occupants of the housing unit to form part of a multi-person household as defined below, or
A multi-person household, i.e. a group of two or more persons who are usually residing together in the whole or part of a housing unit and who provide themselves with food and other essentials for living; with members of the group sharing household income and/or expenses by benefitting from expenses and/or contributing to expenses.
All people who are usual resident, whether related or not related to other members of the private household, are to be considered as members of a private multi-person household if they share household expenses.
3.6. Statistical population
The survey covers all persons living in private households aged 10+.
3.6.1. Main characteristics of the survey population
Individuals living in institutions (nursing homes, homes for the elderly, children's homes, rehabilitation centers and penitentiary) are excluded from the survey population.
3.7. Reference area
The territory of the Republic of Bulgaria.
3.8. Coverage - Time
March 2022 - March 2023
3.9. Base period
Not applicable.
Time spent, participation time and participation rate.
The survey was conducted between 21 March 2022 and 21 March 2023. The surveycovers a full 12 months period, i.e. 365 consecutive days. Each respondent filled in the diary for two days, one weekday (Monday to Friday) and one weekend day (Saturday, Sunday).
6.1. Institutional Mandate - legal acts and other agreements
The Bulgarian Time Use Survey 2020 is a part of National Census program.
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 an informal ’gentlemen's agreement’.
6.1.2. At National level
The conduction of survey is defined in 2021 Population Census and Housing Census in the Republic of Bulgaria Act. The responsible organisation is the National Statistical Institute.
6.2. Institutional Mandate - data sharing
The HETUS 2020 data are available on the BNSI website.
Universities and certified research organisations can apply for access to TUS microdata for scientific purposes.
Individual data are not published in accordance with article 25 of the Bulgarian Law on Statistics. The publishing of individual data can be performed only in accordance with article 26 of the same law.
8.1. Release calendar
The Release Calendar for publishing census data, including data from the Time Use Survey, is available on the BNSI website.
The data and press releases are published on the BNSI website and Information System Infostat in accordance with the Law on Statistics (Chapter 5), Rules for dissemination of statistical products and services of the National Statistical Institute and the European Statistics Code of Practice, respecting professional independence and in an objective, professional and transparent manner in which all users are treated equitably.
Every 10 years.
10.1. Dissemination format - News release
Press release is published on the following webpage.
10.2. Dissemination format - Publications
Not available.
10.3. Dissemination format - online database
Data on Time Use Survey are available to all users of the BNSI website, Information System Infostat.
10.3.1. Data tables - consultations
Not requested.
10.4. Dissemination format - microdata access
Anonymised individual data can be provided for scientific and research purposes by individual request, according to the Rules for the provision of anonymised individual data for scientific and research purposes.
10.5. Dissemination format - other
Information service on request, according to the Rules for the dissemination of statistical products and services in NSI.
10.5.1. Metadata - consultations
Not requested.
10.6. Documentation on methodology
The survey metadata are available on the following BNSI website.
The survey instrumentarium - sample design, questionnaires and guidelines was developed entirely in accordance with the Harmonised European Time Use Surveys (HETUS) — 2018 guidelines.
Training of the fieldwork managers and interviewers has been done.
The coding of the activities was carried out by trained personnel in accordance with HETUS Activity Coding List (ACL) 2018.
11.2. Quality management - assessment
There is a quality management system in the BNSI in accordance with the requirements of ISO 9001:2015. Since 2019, an extended scope of the system has been approved, including receiving the data collection, processing, storing, analyzing, providing and dissemination of statistical information.
Integrated quality and security management system has been implemented in respect of all survey stages and in accordance with the requirements of BDS EN ISO 9001: 2015 and BDS EN ISO 27001: 2017. The certificate fully meets all international requirements and guarantees the quality of the processes and information security of the entire statistical and information infrastructure of the NSI.
12.1. Relevance - User Needs
The produced information answers to the needs of the scientific researchers and government institutions, for the purposes of analysis, planning and monitoring of various national strategies.
12.2. Relevance - User Satisfaction
Not applicable.
12.3. Completeness
All the variables required for transmission have been included in the microdata.
12.3.1. Data completeness - rate
Not requested.
13.1. Accuracy - overall
HETUS is a sample survey and it is designed to represent the entire population of Bulgaria. All indicators from HETUS are estimated with certain statistical accuracy. The statistical accuracy is related to sample size. The larger sample size provide lower standard error and higher accuracy of the estimates. HETUS survey sample size is based on the Bulgarian population living in private households aged 10 and above. The sample size is 3 132 households.
13.2. Sampling error
See below.
13.2.1. Sampling error - indicators
Standard error for the HETUS survey is calculated for the indicator Percentage of population aged 15 and over spending daily on average more than 10 % of time working in paid work.
13.2.2. Sampling error - proportion and confidence interval
Parameter of interest (p̂)
Number of respondents - n
Standard error for p̂
95% confidence interval for p̂: Lower
95% confidence interval for p̂: Upper
Percentage of population aged 15 and over spending daily on average more than 10 % of time working in paid work
(weighted)
Number of individuals that completed at least 1 diary day
(unweighted)
43.5
5340
0.975
41.5
45.4
Calculation of (p̂)
Calculate for all individuals the sum of time spent working (ACL activity 1 employment) considering both diary days. (i.e 48 hours or 2*1440 minutes)
NUMERATOR: Count of the individuals whose cumulative time spent in ACL 2018 activity 1 in both diary days was equal or higher than 10% i.e. 4.8 hours in total. If only one diary was completed then 10% = 2.4 hours
DENOMINATOR: Total number of individuals that completed at least 1 diary day.
To obtain (p̂) calculate the proportion: Numerator/ Denominator
13.2.3. Sampling error - method used for the variance (SE) estimation
Bulgaria uses Taylor linearization to calculate sampling error.
13.3. Non-sampling error
There are few types of non-sampling errors:
Coverage errors: errors due to divergences existing between the target population and the sampling frame;
Measurement errors: errors that occur at the time of data collection. There are a number of sources for these errors, such as the survey instrument, the information system, the interviewer and the mode of collection;
Processing errors: errors in post-data-collection processes such as data entry, keying, editing and weighting;
Non-response errors: errors due to an unsuccessful attempt to obtain the desired information from an eligible unit. Two main types of non-response errors are considered:
1) Unit non-response: refers to absence of information of the whole units (households and/or persons) selected into the sample. 2) Item non-response: refers to the situation where a sample unit has been successfully enumerated, but not all required information has been obtained.
Model assumption errors: errors occur when the underlying conditions assumed by a statistical model are not met by the data or the system being modeled. These errors can lead to inaccurate predictions, unreliable inferences, and flawed conclusions.
13.3.1. Coverage error
Coverage errors include over-coverage, under-coverage and misclassification:
Over-coverage: relates either to wrongly classified units that are in fact out of scope, or to units that do not exist in practice;
Under-coverage: refers to units not included in the sampling frame;
Misclassification: refers to incorrect classification of units that belong to the target population.
The source of the frame is the Census2011. The sampling frame is updated annually based on demographic events.
13.3.1.1. Over-coverage - rate
Coverage-error
Percentage (from the sample)
Comment
Over-coverage
2.6%
Non-contacted addresses for the following reasons:
Address does not exist;
Address is unoccupied;
Address is non-residential address.
13.3.1.2. Common units - proportion
Not applicable.
13.3.2. Measurement error
HETUS survey was conducted using PAPI interview mode only. The activities in the diary were recorded by hand writing from the respondents. Later on the diaries were coded to electronic format. Some misclassifications are possible due to unreadable hand writing.
13.3.2.1. Questionnaire design and testing
The household and individuals questionnaire and the dairy are elaborated in full compliance with the Harmonised European Time Use Surveys (HETUS) 2018 Guidelines.
13.3.2.2. Interviewer training
In the first stage, the training of trainers (representatives from Departments "Statistical Surveys" at the Regional Statistical Offices) is conducted. In the second stage, the trainers conducted training for the interviewers. As a part of the training, the interviewers were provided with the detailed guideline manual for the fieldwork, containing all aspects necessary to execute the survey correctly, the questionnaires and the diaries as well as the Notes for the interviewers.
13.3.2.3. Proxy interview rates
The percentage of proxy interviews is 23.8%
13.3.3. Non response error
Non response errors are errors that occur when the survey fails to get a response to one or possibly all of the questions. For more information please see the next two sections.
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
There are several possible reasons for non-response, e.g.:
Non-contact: if it is not possible to contact the respondents, e.g. they are not at home, inaccessible, etc.
Inability: if the respondents are unable to answer, there are language problems, etc.
Refusal: if the respondents explicitly do not cooperate, e.g. they are not interested, they don't have time, etc.
The detailed breakdow of the above cases can be found in the Annex 13.3.3.1.2. Gross sample.
The specific reasons for "Refusal" cases are not collected.
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
Non-response is manly household occurrence. Due to this characteristics of the specific individuals/respondents cannot be collected.
13.3.3.1.4. Efforts to reduce non-response
The respondents’ address information was sent to the Regional Statistical Offices for checking after the sample selection.
Household invitation letter was prepared and signed by the President of the NSI. In this letter we explain the aim of the survey and how the sample was drawn. The importance to participate is stressed. The households were informed that the interviewers are staff of the Regional statistical offices and will identify themselves by an identity card. We assure the persons that their answers will remain confidential.
13.3.3.1.5. Adjustment of weights in order to reduce non-response
The weighting process has several stages. The first stage sample weights (design weights) are obtained as inverse of inclusion probabilities. In the final stage design weights are calibrated to obtain information from register about the population by the end of the year.
13.3.3.1.6. Other comments regarding non-response errors
No comments.
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
16.9
13.3.3.1.8. Description of the substitution
Bulgaria used stratified two stage cluster sample as sample design. Within each PSU a total number of 15 households were selected. 10 of them were part of the main sample. Non-responding units were substituted with the rest of the 5 households selected from the PSU.
13.3.3.1.9. Qualitative assessment of the bias associated with unit non-response
Not available
13.3.3.2. Item non-response - rate
Item non-response is generally low. However, there are few variables with high item non-response. They are described in the following section.
13.3.3.2.1. Variables most subject to item non-response
There are few variables which were part of the TUS Diary with high item non-response. These are:
Most pleasant activity during diary day;
Most unpleasant activity during diary day;
Most stressful activity during diary day.
These variables were put at the end of the dairy so the respondents could provide the information after finishing with the diary. The diaries were left to the respondents for filling in during the upcoming 24 hours. Unfortunately, the respondents didn’t provide answers to all questions. The interviewers took the questionnaire/diary from the respondents and later on checked for completeness. As consequences, at least one third of the above mentioned variables have not been answered.
13.3.4. Processing error
Data checking, cleaning and editing were done in accordance with the proposed by Eurostat guidelines and documents. Errors caused by the interviewers, as well as errors introduced during data-entry, were cleaned and edited. Many consistency checks are implemented in the data entry software, which allows for simultaneous correction. Additional checks for logical consistence are carried out over the aggregated files. Data processing was performed with SPSS.
13.3.5. Model assumption error
Bulgarian NSI didn't use modeling during the data processing of the HETUS survey.
14.1. Timeliness
Data are available to users 16 months after the end of fieldwork. The fieldwork ended on 31 March 2023.
The data were transmited to Eurostat in August 2024.
The data were published on BNSI webpage in September 2024.
14.1.1. Time lag - first result
Not applicable.
14.1.2. Time lag - final result
Not applicable.
14.2. Punctuality
The data were delivered 16 month after the end of data collection.
14.2.1. Punctuality - delivery and publication
Not requested.
15.1. Comparability - geographical
The sample design ensures high comparability of data between regions at the level NUTS3.
15.1.1. Asymmetry for mirror flow statistics - coefficient
Not applicable.
15.2. Comparability - over time
There are no significant deviations in the methodology and instrumentarium used compared to the previous wave of the survey.
15.2.1. Length of comparable time series
Not requested.
15.3. Coherence - cross domain
Not applicable.
15.3.1. Coherence - sub annual and annual statistics
Not applicable.
15.3.2. Coherence - National Accounts
Not requested.
15.4. Coherence - internal
The diferent outputs are internally consistent.
Information on Cost and burden is provided in the sub-concepts 16.1 – 16.4.
16.1. Costs of the survey
The National Time Use Survey is the part of Census 2021 programme and budget.
16.2. Average time used for answering the survey questionnaires (in minutes)
Average time (in minutes) needed for the respondents to fill in the household questionnaire - 20
Average time (in minutes) needed for the respondents to fill in the individual questionnaire - 16
16.3. Average time used to fill in the diary (in minutes)
Not applicable.
16.4. Measures taken to reduce the cost and burden of the survey
The CAPI is used as a method of data collection for filling the household and individual questionnaire.
17.1. Data revision - policy
Not applicable.
17.2. Data revision - practice
Not applicable.
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
Population and housing Census 2011
Population register
No
Household register
No
Dwelling register
No
List of phone numbers
No
Postcode address file
No
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
Systematic sampling
Stratified sampling
X
Cluster sampling
X
Other
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
Bulgaria uses country specification with combination of the Precision requirements specified in Annex II of Regulation 2019/1700 to determine appropriate sample size for HETUS 2022.
18.1.3. Sample size
Sample size
Number
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.
3132 households
Number of eligible units
Formula: net sample size= Gross sample size - units with unknown eligibility – ineligible units
3024 household
Achieved sample size = Total number of households which were successfully surveyed (interviews+diary)
2887 households
18.2. Frequency of data collection
The survey is conducted every ten years.
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)
No
Computer-assisted personal interview (CAPI)
Yes
100% for household and individual questionnaires
Computer assisted telephone interview (CATI)
No
Computer assisted web-interview (CAWI)
No
Smart mode (e.g. smartphone app)
No
Other (e.g. administrative data).
No
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
Online web diary
No
Mobile based diaries (Smartphone apps, etc.)
No
18.3.4. Variables completed from an external source
Not applicable.
18.4. Data validation
In the process of data-entry, the logical controls are applied between different questions and questionnaires.
During the data processing of the primary data the requirements and filters, required by Harmonised European Time Use Surveys (HETUS) — 2018 guidelines were adopted.
Additional compatibility checks are performed before publishing the information.
The data are validated also by Eurostat.
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 in the Full metadata.
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 weighting process has several stages. The first stage sample weights (design weights) are obtained as inverse of inclusion probabilities. The non-response adjustment is not required because of the used substitution approach.
In the final stage design weights are calibrated to obtain information from register about the population by the end of the year. The calibration procedure was done using SAS macro calmar 2.
Survey name(s) in the national language(s): Изследване на бюджета на времето
Survey name in English: Harmonised European Time Use Survey
Year(s) of (data collection) of the survey: 2022 - 2023
Link to the survey website (only available in Bulgarian)
National questionnair: please see the Annex (only available in Bulgarian)
Time use surveys (TUS) measure the amount of time people spend doing various activities, such as paid work, household and family care, personal care, voluntary work, social life, travel, and leisure activities. The survey consists of a household interview, a personal interview, a weekday diary and a weekend diary. Data are acquired by interviewing the sampled hoseholds and individuals directly and self-completion in the diary.
This domain provides population estimates for activities according to the HETUS-ACL for three main indicators:
Time spent: mean time spent on the activities by all individuals;
Participation time: mean time spent in the activities by those individuals who took part in the activity; and
Participation rate: the proportion of the individuals that spent some time doing the activities.
The scope of the Time Use Surveys is the usual resident population of the country aged 10 and over and living in private households.
The observation units are person, household and time.
Definition of usual resident population "Usual residence" means the place where a person normally spends the daily period of rest, regardless of temporary absences for purposes of recreation, holidays, visits to friends and relatives, business, medical treatment or religious pilgrimage. The following persons alone shall be considered to be usual residents of a specific geographical area:
those who have lived in their place of usual residence for a continuous period of at least 12 months before the reference time; or
those who arrived in their place of usual residence during the 12 months before the reference time with the intention of staying there for at least one year.
Definition of private household "Private household" means a person living alone or a group of people who live together providing themselves with the essentials of living, being either:
A one-person household, i.e. a person who usually resides alone in a separate housing unit or who occupies, as a lodger, a separate room or rooms of a housing unit but does not join with any of the other occupants of the housing unit to form part of a multi-person household as defined below, or
A multi-person household, i.e. a group of two or more persons who are usually residing together in the whole or part of a housing unit and who provide themselves with food and other essentials for living; with members of the group sharing household income and/or expenses by benefitting from expenses and/or contributing to expenses.
All people who are usual resident, whether related or not related to other members of the private household, are to be considered as members of a private multi-person household if they share household expenses.
The survey covers all persons living in private households aged 10+.
The territory of the Republic of Bulgaria.
The survey was conducted between 21 March 2022 and 21 March 2023. The surveycovers a full 12 months period, i.e. 365 consecutive days. Each respondent filled in the diary for two days, one weekday (Monday to Friday) and one weekend day (Saturday, Sunday).
HETUS is a sample survey and it is designed to represent the entire population of Bulgaria. All indicators from HETUS are estimated with certain statistical accuracy. The statistical accuracy is related to sample size. The larger sample size provide lower standard error and higher accuracy of the estimates. HETUS survey sample size is based on the Bulgarian population living in private households aged 10 and above. The sample size is 3 132 households.
Time spent, participation time and participation rate.
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 in the Full metadata.
Information on sampling design, sampling frame and size is available under the full metadata concepts 18.1.1-18.1.3.
Every 10 years.
Data are available to users 16 months after the end of fieldwork. The fieldwork ended on 31 March 2023.
The data were transmited to Eurostat in August 2024.
The data were published on BNSI webpage in September 2024.
The sample design ensures high comparability of data between regions at the level NUTS3.
There are no significant deviations in the methodology and instrumentarium used compared to the previous wave of the survey.
