Technical Note

   The estimates in this news release are based on annual average data from the
American Time Use Survey (ATUS). The ATUS, which is conducted by the U.S. Census
Bureau for the Bureau of Labor Statistics (BLS), is a continuous survey about
how individuals age 15 and over spend their time.

   Information in this news release will be made available to sensory impaired
individuals upon request. Voice phone: (202) 691-5200; Federal Relay Service:
(800) 877-8339.

Survey methodology

   Data collection for the ATUS began in January 2003. Sample cases for the
survey are selected monthly, and interviews are conducted continuously
throughout the year. In 2018, approximately 9,600 individuals were
interviewed. Estimates are released annually.

   ATUS sample households are chosen from the households that completed their
eighth (final) interview for the Current Population Survey (CPS), the nation's
monthly household labor force survey. ATUS sample households are selected to
ensure that estimates will be nationally representative.

   One individual age 15 or over is randomly chosen from each sampled
household. This "designated person" is interviewed by telephone once about
his or her activities on the day before the interview--the "diary day."

   All ATUS interviews are conducted using Computer Assisted Telephone 
Interviewing. Procedures are in place to collect information from the small
number of households that did not provide a telephone number during the CPS
interview.

   ATUS designated persons are preassigned a day of the week about which to
report. Preassignment is designed to reduce variability in response rates
across the week and to allow oversampling of weekend days so that accurate
weekend day measures can be developed. Interviews occur on the day following
the assigned day. For example, a person assigned to report about a Monday
would be contacted on the following Tuesday. Ten percent of designated
persons are assigned to report about each of the five weekdays. Twenty-five
percent are assigned to report about each weekend day. Households are called
for up to 8 consecutive weeks (for example, 8 Tuesdays) in order to secure
an interview.

About the questionnaire

   In the time diary portion of the ATUS interview, survey respondents
sequentially report activities they did between 4 a.m. on the day before the
interview until 4 a.m. on the day of the interview. For each activity, 
respondents are asked how long the activity lasted. For activities other
than personal care activities (such as sleeping and grooming), interviewers
also ask respondents where they were and who was in the room with them (if
at home) or who accompanied them (if away from home). If respondents report
doing more than one activity at a time, they are asked to identify which
one was the "main" (primary) activity. If none can be identified, then the
interviewer records the first activity mentioned. After completing the time
diary, interviewers ask respondents additional questions to clearly identify
work, volunteering, eldercare, and secondary childcare activities. Secondary
childcare is defined as having a child under age 13 in one’s care while doing
other activities.

   In addition, the ATUS includes an update of the household composition from
the last CPS interview (2 to 5 months prior to the ATUS interview), the labor
force status of the respondent, and the employment status of his or her spouse
or unmarried partner. For respondents who became employed or changed jobs
between the last CPS interview and the ATUS interview, information also is
collected on industry, occupation, class of worker, and earnings. Finally, a
question about current school enrollment status is asked of all respondents
ages 15 to 49.

   After completing the interview, primary activity descriptions are assigned
a single 6-digit code using the ATUS Coding Lexicon. The 3-tier coding system
consists of 17 major activity categories, each with multiple second- and
third-tier subcategories. These coding lexicon categories are then combined
into composite categories for publication, such as in this news release.
Descriptions of categories shown in this release can be found in the Major
activity category definitions section of this Technical Note. The ATUS Coding
Lexicon can be accessed at www.bls.gov/tus/lexicons.htm.

   Because of the complexity of coding everyday activities into narrowly-
defined lexicon categories, coders use a comprehensive set of rules to guide
their decisions. In order to capture useful and detailed information, travel
activities are coded according to the purpose of travel. For more information
about coding travel, see Exhibit 5.1 of the ATUS User's guide at
www.bls.gov/tus/atususersguide.pdf.

Concepts and definitions

   Average day. The average day measure reflects an average distribution across
all persons in the reference population and all days of the week. The ATUS
collects data about daily activities from all segments of the population age 15
and over, including persons who are employed and not employed. Activity profiles
differ based upon age, employment status, sex, and other characteristics. For
example, in 2018, persons in the United States age 15 and over spent 3.2 hours
per day working. By comparison, on an average weekday they worked, full-time
employed persons spent 8.5 hours working. Many activities typically are not done
on a daily basis, and some activities only are done by a subset of the population.

   Average hours per day. The average number of hours spent in a 24-hour day
(between 4 a.m. on the diary day and 4 a.m. on the interview day) doing a
specified activity.

   --Average hours per day, population. The average number of hours per day is
     computed using all responses from a given sample of the population,
     including those of respondents who did not do a particular activity on
     their diary day. These estimates reflect how many persons engaged in an
     activity and the amount of time they spent doing it.

   --Average hours per day, persons who did the activity. The average number of
     hours per day is computed using only responses from those who engaged in a
     particular activity on their diary day.

   Diary day. The diary day is the day about which the respondent reports. For
example, the diary day of a respondent interviewed on Tuesday is the preceding
Monday.

Earnings

   --Usual weekly earnings. Estimates represent the earnings of full-time wage
     and salary workers with one job only (both incorporated and unincorporated
     self-employed are excluded), before taxes and other deductions. They 
     include any overtime pay, commissions, or tips usually received. Usual
     weekly earnings are updated in the ATUS for just over one-third of wage
     and salary workers--if the respondent changed jobs or employment status
     between the CPS and ATUS interviews, or if the CPS weekly earnings value
     was imputed. This means that the earnings information could be out of
     date because the CPS interview was done 2 to 5 months prior to the ATUS
     interview. Respondents are asked to identify the easiest way for them to
     report earnings (hourly, weekly, biweekly, twice monthly, annually, or
     other) and how much they usually earn in the reported time period. Earnings
     reported on a basis other than weekly are converted to a weekly equivalent.
     The term "usual" is as perceived by the respondent. If the respondent asks
     for a definition of usual, interviewers are instructed to define the term
     as more than half the weeks worked during the past 4 or 5 months.

   --Weekly earnings ranges. The ranges used represent approximately 25 percent
     of full-time wage and salary workers (both incorporated and unincorporated
     self-employed are excluded) who held only one job. For example, 25 percent
     of full-time wage and salary workers with one job only had weekly earnings
     of $630 or less in 2018. These dollar values vary from year to year.

Employment status

   --Employed. All persons who:

     1) At any time during the 7 days prior to the interview did any work at all
        as paid employees, or worked in their own business or profession or on
        their own farm; or

     2) Were not working during the 7 days prior to the interview but had jobs
        or businesses from which they were temporarily absent because of illness,
        bad weather, vacation, childcare problems, labor-management disputes,
        maternity or paternity leave, job training, or other family or personal
        reasons, whether or not they were paid for the time off or were seeking
        other jobs; or

     3) Usually worked 15 hours or more as unpaid workers in a family-operated
        enterprise.

   --Employed full time. Full-time workers are those who usually worked 35 or
     more hours per week at all jobs combined.

   --Employed part time. Part-time workers are those who usually worked fewer
     than 35 hours per week at all jobs combined.

   --Not employed. Persons are not employed if they do not meet the conditions
     for employment. Those who are not employed include individuals classified
     as unemployed as well as those classified as not in the labor force (using
     CPS definitions).

   The numbers of employed and not employed persons in this release do not
correspond to published totals from the CPS for several reasons. First, the
reference population for the ATUS is age 15 years and over, whereas it is age
16 years and over for the CPS. Second, ATUS data are collected continuously,
the employment reference period being the 7 days prior to the interview. By
contrast, CPS data are usually collected during the week including the 19th
of the month and generally refer to employment during the week containing the
12th of the month. Finally, the CPS accepts answers from household members
about other household members whereas such proxy responses are not allowed in
the ATUS. One consequence of the difference in proxy reporting is that a
significantly higher proportion of teenagers report employment in the ATUS
than in the CPS. While the information on employment from the ATUS is useful
for assessing work in the context of other daily activities, the employment
data are not intended for analysis of current employment trends. Compared with
the CPS and other estimates of employment, the ATUS estimates are based on a
much smaller sample and are only available with a substantial lag since ATUS
data and estimates are published during the year following data collection.

   Household children. Household children are children under age 18 residing
in the household of the ATUS respondent. The children may be related to the
respondent (such as his or her own children, grandchildren, nieces or nephews,
or brothers or sisters) or not related (such as foster children or children
of roommates or boarders).

   Primary activity. A primary activity is the main activity a respondent was
doing at a specified time. With the exception of secondary childcare in
table 10, the estimates presented in this release reflect time spent in
primary activities only.

   Secondary activities. A secondary (or simultaneous) activity is an activity
done at the same time as a primary activity. With the exception of the care of
children under age 13, information on secondary activities is not collected in
the ATUS.

   Secondary childcare. Secondary childcare is care for children under age 13
that is done while doing an activity other than primary childcare, such as
cooking dinner. Secondary childcare estimates are derived by summing the
durations of activities during which respondents had at least one child under
age 13 in their care while doing other things. The time individuals spend
providing secondary childcare is further restricted to the time between when
the first household child under age 13 woke up and when the last household
child under age 13 went to bed. It is also restricted to times the respondent
was awake. If respondents report providing both primary and secondary care at
the same time, the time is attributed to primary care only.

   Weekday, weekend, and holiday estimates. Estimates for weekdays are an
average of reports about Monday through Friday, excluding holidays. Estimates
for weekend days and holidays are an average of reports about Saturdays,
Sundays, and the following holidays:  New Year's Day, Easter, Memorial Day,
the Fourth of July, Labor Day, Thanksgiving Day, and Christmas Day. Data
were not collected about Christmas Day in 2014 and 2016, and New Year’s Day
in 2017.

Major activity category definitions

   The following definitions describe the activity categories shown in this
report. All major time-use categories in this release include related travel
time and waiting time. For example, time spent "driving to the stadium" and
time spent "waiting to get into the stadium to play ball" are included in
Leisure and sports.

   Personal care activities. Personal care activities include sleeping, grooming
(such as bathing or dressing), health-related self-care, and personal or private
activities. Receiving unpaid personal care from others (for example, "my sister
put polish on my nails") also is captured in this category. In general, respondents
are not asked who they were with or where they were for personal care activities,
as such information can be sensitive.

   Eating and drinking. All time spent eating or drinking (except eating and
drinking done as part of a work or volunteer activity), whether alone, with
others, at home, at a place of purchase, or somewhere else, is classified here.

   Household activities. Household activities are activities done by individuals
to maintain their households. These include housework; cooking; lawn and garden
care; pet care; vehicle maintenance and repair; home maintenance, repair,
decoration, and renovation; and household management and organizational activities
(such as filling out paperwork or planning a party). Food preparation, whether
or not reported as done specifically for another household member, is always
classified as a household activity unless it was done as a volunteer, work, or
income-generating activity. For example, "making breakfast for my son" is coded
as a household activity, not as childcare.

   Purchasing goods and services. This category includes time spent purchasing
consumer goods, professional and personal care services, household services,
and government services. Consumer purchases include most purchases and rentals
of consumer goods, regardless of the mode or place of purchase or rental (in
person, online, via telephone, at home, or in a store). Gasoline, grocery,
other food purchases, and all other shopping are further broken out in
subcategories.

   Time spent obtaining, receiving, and purchasing professional and personal
care services provided by someone else also is classified in this category.
Professional services include childcare, financial services and banking, legal
services, medical and adult care services, real estate services, and veterinary
services. Personal care services include day spas, hair salons and barbershops,
nail salons, and tanning salons. Activities classified here include time spent
paying, meeting with, or talking to service providers, as well as time spent
receiving the service or waiting to receive the service.

   Time spent arranging for and purchasing household services provided by someone
else also is classified here. Household services include housecleaning; cooking;
lawn care and landscaping; pet care; tailoring, laundering, and dry cleaning;
vehicle maintenance and repairs; and home repairs, maintenance, and construction.

   This category also captures the time spent obtaining government services--
such as applying for food assistance--and purchasing government-required licenses
or paying fines or fees.

   Caring for and helping household members. Time spent doing activities to
care for or help any child (under age 18) or adult in the household, regardless
of relationship to the respondent or the physical or mental health status of
the person being helped, is classified here. Caring for and helping activities
for household children and adults are coded separately in subcategories.

   Primary childcare activities include time spent providing physical care;
playing with children; reading with children; assistance with homework;
attending children's events; taking care of children's health needs; and
dropping off, picking up, and waiting for children. Passive childcare done
as a primary activity (such as "keeping an eye on my son while he swam in the
pool") also is included. A child's presence during the activity is not enough
in itself to classify the activity as childcare. For example, "watching
television with my child" is coded as a leisure activity, not as childcare.

   Secondary childcare occurs when persons have a child under age 13 "in their
care" while doing activities other than primary childcare. For a complete
definition, see the Concepts and definitions section of this Technical Note.

   Caring for and helping household members also includes a range of activities
done to benefit adult members of households, such as providing physical and
medical care or obtaining medical services. Doing something as a favor for or
helping another household adult does not automatically result in classification
as a helping activity. For example, a report of "helping my spouse cook dinner"
is considered a household activity (food preparation), not a helping activity,
because cooking dinner benefits the household as a whole. By contrast, doing
paperwork for another person usually benefits the individual, so a report of
"filling out an insurance application for my spouse" is considered a helping
activity.

   Caring for and helping nonhousehold members. This category includes time
spent in activities done to care for or help others--both children (under
age 18) and adult--who do not live in the household. When done for or through
an organization, time spent helping nonhousehold members is classified as
volunteering, rather than as helping nonhousehold members. Care of nonhousehold
children, even when done as a favor or helping activity for another adult, is
always classified as caring for and helping nonhousehold children, not as
helping another adult.

   Working and work-related activities. This category includes time spent
working, doing activities as part of one's job, engaging in income-generating
activities not as part of one's job, and job search activities. "Working"
includes hours spent doing the specific tasks required of one's main or
other job, regardless of location or time of day. "Work-related activities"
include activities that are not obviously work but are done as part of one's
job, such as having a business lunch and playing golf with clients. "Other
income-generating activities" are those done "on the side" or under informal
arrangement and are not part of a regular job. Such activities might include
selling homemade crafts, maintaining a rental property, or having a yard sale.
These activities are those for which individuals are paid or will be paid.

   Travel time related to working and work-related activities includes time
spent traveling to and from work, as well as time spent traveling for work-
related, income-generating, and job search activities.

   Educational activities. Time spent taking classes for a degree or for
personal interest (including taking internet or other distance-learning
courses), time spent doing research and homework, and time spent taking
care of administrative tasks related to education (such as registering for
classes or obtaining a school ID) are included in this category. For high
school students, before- and after-school extracurricular activities (except
sports) also are classified as educational activities. Educational activities
do not include time spent for classes or training received as part of a job.
Time spent helping others with their education-related activities is classified
as an activity involving caring for and helping others.

   Organizational, civic, and religious activities. This category captures time
spent volunteering for or through an organization, performing civic obligations,
and participating in religious and spiritual activities. Civic obligations
include government-required duties, such as serving jury duty or appearing in
court, and activities that assist or influence government processes, such as
voting or attending town hall meetings. Religious activities include those
normally associated with membership in or identification with specific religions
or denominations, such as attending religious services; participating in choirs,
youth groups, orchestras, or unpaid teaching (unless identified as volunteer
activities); and engaging in personal religious practices, such as praying.

   Leisure and sports. The leisure and sports category includes time spent in
sports, exercise, and recreation; socializing and communicating; and other
leisure activities. Sports, exercise, and recreation activities include
participating in--as well as attending or watching--sports, exercise, and
recreational activities. Recreational activities include yard games like
croquet or horseshoes, as well as activities like billiards and dancing.
Socializing and communicating includes face-to-face social communication and
hosting or attending social functions. Leisure activities include watching
television; reading; relaxing or thinking; playing computer, board, or card
games; using a computer or the internet for personal interest; playing or
listening to music; and other activities, such as attending arts, cultural,
and entertainment events.

   Telephone calls, mail, and e-mail. This category captures time spent in
telephone communication and household or personal mail or e-mail. This category
also includes texting and internet voice and video calling. Telephone and
internet purchases are classified in Purchasing goods and services. Telephone
calls, mail, or e-mail identified as related to work or volunteering are
classified as work or volunteering.

   Other activities, not elsewhere classified. This residual category includes
security procedures related to traveling, traveling not associated with a
specific activity category, ambiguous activities that could not be coded, and
missing activities. Missing activities result when respondents did not remember
what they did for a period of time, or when they considered an activity too
private or personal to report.

Processing and estimation

   After ATUS data are collected, they go through an editing and imputation
procedure. Responses to CPS questions that are re-asked in the ATUS go through
the regular CPS edit and imputation procedures. Some item nonresponses for
questions unique to the ATUS (such as where an activity took place or how much
time was spent doing secondary childcare) also are imputed. Missing activities
and missing values for who was present during an activity are never imputed.

   ATUS records are weighted quarterly to reduce bias in the estimates due to
differences in sampling and response rates across subpopulations and days of
the week. Specifically, the data are weighted to ensure the following:

   --Weekdays represent about 5/7 of the weighted data, and weekend days
     represent about 2/7 of the weighted data for the population as a
     whole. The actual proportions depend on the number of weekdays and
     weekend days in a given quarter.

   --The sum of the weights is equal to the number of person-days in the
     quarter for the population as a whole and for selected subpopulations.

Reliability of the estimates

   Statistics based on the ATUS are subject to both sampling and nonsampling
error. When a sample, rather than the entire population, is surveyed, estimates
differ from the true population values they represent. The component of this
difference that occurs because samples differ by chance is known as sampling
error, and its variability is measured by the standard error of the estimate.

   Sample estimates from a given survey design are unbiased when an average of
the estimates from all possible samples would yield, hypothetically, the true
population value. In this case, the sample estimate and its standard error can
be used to construct approximate confidence intervals, or ranges of values that
include the true population value with known probabilities. If the process of
selecting a sample from the population were repeated many times, an estimate
made from each sample, and a suitable estimate of its standard error calculated
for each sample, then approximately 90 percent of the intervals from 1.645
standard errors below the estimate to 1.645 standard errors above the estimate
would include the true population value. BLS analyses are generally conducted
at the 90-percent level of confidence.

   The ATUS data also are affected by nonsampling error, which is the average
difference between population and sample values for samples generated by a given
process. Nonsampling error can occur for many reasons, including failure to
sample a segment of the population, inability to obtain information for all
persons in the sample, inability or unwillingness of respondents to provide
correct information, and errors made in the collection or processing of the
data. Errors also could occur if nonresponse is correlated with time use.

Publication requirements

   Estimates of average hours per day and participation rates are not published
unless there are a minimum number of respondents representing the given population.
Additional publication criteria are applied that include the number of respondents
who reported doing a specified activity and the standard error or coefficient of
variation for the estimate. Estimates that are considered "close to zero" or
that round to 0.00, are published as approximately zero or "~0." For a detailed
description of the statistical reliability criteria necessary for publication,
please contact ATUS staff at ATUSinfo@bls.gov.