BLS WORKING PAPERS 

 U.S. Department of Labor 

U.S. Bureau of Labor Statistics

Office of Employment and Unemployment Research 

Secondary Activities in the 2006 American Time Use Survey

Robert Drago, Institute for Women’s Policy Research

Working Paper 446

February 2011

All views expressed in this paper are those of the authors and do not necessarily reflect the views or policies of the

U.S. Bureau of Labor Statistics.
1

Secondary Activities in the 2006 American Time Use Survey1

Report to the U.S. Bureau of Labor Statistics 

August 8, 2008 

Robert Drago 

Research Director 

Institute for Women’s Policy Research 

All views expressed in this paper are those of the author and they do not necessarily 

reflect the views or policies of the U.S. Bureau of Labor Statistics. 

 

1

 This research was supported by a fellowship from the American Statistical Association, National Science 

Foundation, and Bureau of Labor Statistics, and the research was performed at BLS. The author thanks 

those organizations and Mary Dorinda Allard and Jay Stewart for their generous help with the data and 

analyses, and the Bureau of the Census for coding the secondary activities data and for providing the 

precoding results reported in Table 4. The STATA program and data used to generate all other results 

reported here are available from the author at IWPR, 1200 18th St NW, Suite 301, Washington DC 20009, 

or drago@iwpr.org. 
2

Abstract 

A major criticism of the American Time Use Survey (ATUS) is that, with the exception 

of childcare, the survey does not systematically collect information about activities 

respondents did while they were doing something else. The ATUS focuses on collecting 

information about respondents' main (or primary) activities; when respondents volunteer 

that they were doing secondary activities, this information is recorded by the 

interviewers, but it is not coded and does not appear in the final data. This study is an 

analysis of these additional secondary activity data from 2006. The study provides 

descriptive information about who reported secondary activities and the activities they 

reported. It also quantifies the secondary activity time that was spent in nonmarket work 

and examines whether the omission of these data impacts valuations of nonmarket work. 

Finally, it evaluates the quality of the voluntarily-reported secondary activity data. 
3

Secondary Activities in the 2006 American Time Use Survey 

Traditional time-use diaries ask respondents “what they were doing” and if they “were 

doing anything else” during various portions of a 24-hour day (e.g., Bianchi, Robinson 

and Milkie, 2006). These questions are used to collect information about activities that 

people do simultaneously. The first question generates information about the primary, or 

main, activities people were doing at a given time while the second question yields data 

on additional, or secondary, activities that they were doing. For example, someone who 

was preparing dinner and watching television at the same time would need to identify 

which of these was his primary activity and which was his secondary activity in reporting 

this information. 

The American Time Use Survey (ATUS), the largest-scale time-use study administered 

in the United States to date, does not explicitly ask respondents to report secondary 

activities other than secondary childcare; instead, its focus is on the collection of 

information about respondents' primary activities. However, if respondents voluntarily 

report doing two or more activities at the same time, the ATUS interviewers record all 

activities that were mentioned. Secondary activity data from the ATUS were neither 

coded nor analyzed until recently; here, I explore these data from the 2006 ATUS. For 

present purposes, I distinguish secondary activity reports according to whether the 

information was explicitly requested from respondents or was instead volunteered, as is 

done in the ATUS. 

Background 

Many time-use researchers have argued that time-use studies should systematically 

collect data about secondary activities. Alexander Szalai, an early pioneer of time-use 

studies, wrote: 

 Elimination of secondary or parallel activities from the circle of observation 

naturally distorts in a rather arbitrary fashion the picture of what people do the 

 daylong and leads to a biased account of the amounts of time they devote to the 

various tasks of life. (1972, p. 3) 

In practice, however, secondary activity data usually are ignored in time-use analyses 

(e.g., see Bianchi, et al., 2006). When they are analyzed, the researchers typically take 

the naïve approach of dividing the time spent in the episode between the two activities. 

A person who is eating and watching television for an hour would be classified as having 

spent one-half hour in each activity. 

It is not obvious how time spent in secondary activities should be counted, because 

reported secondary activities can be either true simultaneous activities or short-duration 

sequential activities that are reported as secondary. An example of true simultaneous 

activities is "preparing dinner" while "listening to the radio," whereas an example of a 
4

short-duration sequential activity reported as secondary might be "getting the mail" while 

"watching TV." 

One reason time-use data are collected is to learn more about the time people spend doing 

unpaid work. Unpaid work refers to activities one could hire someone else to do rather 

than doing for oneself, and it can be measured directly as a primary activity in any timeuse data set, including the ATUS. Unpaid work is typically captured in two time-use 

categories: household activities (which mainly involve unpaid work in and around the 

home) and childcare. However, many unpaid work activities are either of short duration 

or lend themselves to being done simultaneous to other activities. For example, an 

individual may shift laundry from the washer to the dryer in the middle of watching a 

television show, or mind a child while cooking, cleaning, or reading a novel. In each of 

these cases, it is possible that some unpaid work would be excluded from the reported 

primary activities, but included in the secondary activity data. 

Childcare tends to account for most of the time devoted to unpaid work as a secondary 

activity. Harvey analyzed data from one Australian and four U.S. studies, and found that 

childcare accounted for between three-quarters and nine-tenths of the secondary activity 

time classified as either household activities or childcare (2006, p. 201). 

The ATUS collects information on the time respondents spent caring for any child under 

the age of 13 by asking whether a child of this age was “in your care” and, if so, during 

which activities. This construct was designed to capture time the respondent was “able to 

provide assistance to the child if necessary” (Allard, et al., 2007, p.34). As such, it fits 

within the definition of unpaid work as any “activity... that... might be delegated to a 

paid [employee]” (Reid 1934, p. 11). The restriction of the measure to younger children 

(those under age 13) is sensible when viewed in this light since parents of young children 

typically do not leave them untended for long periods of time. Admittedly, around 7 

percent of children below the age of 13 regularly spend some portion of their day in selfcare (Drago 2007, p. 41), but that number is small enough to suggest that most parents 

would and do often find or pay someone else to care for the child when they cannot 

provide assistance. 

The ATUS measure of secondary childcare captures more time than traditional measures 

of childcare as a secondary activity. In a comparison of the 2003-04 ATUS data with 

figures from the 2000 National Survey of Parents (NSP)–which used the more traditional 

"what else were you doing?" question—it was found that parents averaged around threequarters of an hour on childcare as a secondary activity in the NSP, but that parents of 

children under 13 averaged almost 6 hours per day on secondary childcare in the ATUS 

(Allard et al., 2007, p. 31). Consistent with the view that “in your care” time represents 

unpaid work, Folbre and Yoon (2008) placed a monetary value on this time in an analysis 

of the 2003 ATUS data. 

Given that the ATUS does not request information on secondary activities other than 

childcare, it is reasonable to conclude that, on the one hand, measures of unpaid work 

developed from the data will be understated because time devoted to housework as a 
5

secondary activity is not counted. On the other hand, measures of unpaid work that are 

generated from time-use surveys asking "What else were you doing?" to collect 

secondary activities will understate time spent in childcare as a secondary activity. Given 

the amounts of time involved, the understatement of childcare time in traditional surveys 

is likely far larger than the understatement of housework in the ATUS, perhaps by a 

factor of as much as 25 for parents of children under the age of 13.2

 Regardless of the 

much larger magnitude of the childcare divergence, it would be desirable to pick up 

missing housework time in the ATUS, and secondary activity data might serve that 

purpose. 

Not surprisingly, given the discussion to this point, earlier studies find that secondary 

activities tend to occur in and around the home (Harvey 2006, p. 208). However, 

childcare and housework comprise only a minority of those activities. Passive leisure in 

the form of watching television, listening to the radio, or having a conversation accounts 

for a majority of secondary activity time in those studies. Arguably, being at home lends 

itself to messy, overlapping and short duration uses of time in a way that being in the 

workplace or even traveling does not (Kitterod 2001). To the extent that secondary 

activity reports reflect this messiness, there may be more secondary activity reports in the 

ATUS data for times when respondents were at home. 

It also seems reasonable to expect that busier people will more often report secondary 

activities. If an individual experiences significant time pressures, he or she may respond 

by speeding up activities and reducing the average duration, and short duration activities 

may be reported as secondary activities. Further, busy individuals might respond by 

multitasking—that is, doing multiple activities at once—in an effort to alleviate time 

pressures and, with the exception of childcare, secondary activity reports provide the only 

method for respondents to provide information on multitasking in the ATUS. Busy 

respondents seem most likely to be those who are women, who work long hours, and who 

have children and particularly young children. 

As suggested earlier, secondary activity reports are likely to include both truly 

simultaneous as well as short duration, sequential activities. Kitterod (2001) argues that 

truly simultaneous activities should be reported as secondary, while sequential activities 

belong in primary activity reports. To the extent there is an advantage to the volunteered 

method of secondary activity data collection used with the ATUS, it is that respondents 

may be more likely to report short duration, sequential activities as in fact primary. 

In sum, volunteered ATUS secondary activity data (not including the ATUS measure of 

secondary childcare) will: a) capture housework that would otherwise be missed, b) tend 

to be located in the home, c) be associated with people who are busy, and d) tend to pick 

up truly simultaneous rather than short duration, sequential activities. The analysis below 

is more general, but these four issues receive much attention. 

 

2

 If individuals report three-quarters of an hour of secondary childcare (as in the 2000 NSP), Harvey’s 

results suggest that the ATUS misses around one-quarter of an hour of secondary housework. The “in your 

care” figure suggests that traditional secondary childcare measures miss around five hours per day, which is 

around 25 times as large. 
6

Data 

The ATUS is a stratified three-stage sample drawn from households that have recently 

completed their participation in the Current Population Survey (CPS). CPS households are 

stratified based on their characteristics, and ATUS sample households are randomly 

selected from those strata. One individual is then randomly selected from the list of adult 

(age 15 or older) household members. All adults within a household have the same 

probability of being selected. One-half of the adults are then assigned a weekend day and 

one-half are assigned a weekday about which they are interviewed about their time use. 

The survey is designed to be nationally representative of the civilian noninstitutional 

population age 15 and older. 

The ATUS is sponsored by the Bureau of Labor Statistics and is conducted by the U.S. 

Census Bureau using computer-assisted telephone interviewing (CATI) technology. All 

ATUS respondents are assigned an initial day about which they will be interviewed about 

their time use, and they are called on the following day. If the respondent is unavailable 

on that day, subsequent contact attempts are made on the same day of subsequent weeks. 

This procedure maintains the proportional assignment of respondents to days of the week. 

The ATUS’s core time diary is very similar to other time-budget surveys. The 

respondent is asked to sequentially describe his or her day from 4 AM “yesterday” 

through 4 AM “today.” The respondent describes each activity, which the interviewer 

either records verbatim or, for a limited set of commonly-performed, unambiguouslydefined activities (such as sleeping or watching television), enters a pre-code. When a 

pre-code is used, an activity code is automatically assigned to the activity. If a 

respondent voluntarily mentions secondary activities, an ATUS interviewer asks the 

respondent to try to separate the activities into distinct time episodes. If he is unable to 

divide the activities, the interviewer asks the respondent which of the activities was his 

main activity and records this activity first, followed by the secondary activity.3

 While 

both the primary and secondary activity data are recorded, only the primary activity is 

assigned a code and appears in the final ATUS data set. The verbatim responses are 

coded to a three-tier scheme, going from major activity categories, to sub-categories, to 

descriptions of very specific actions that together comprise a single third-tier activity. 

For each episode, the ATUS interviewer collects either the ending time or the duration of 

the activity. In addition, for each activity the interviewer asks where the respondent was 

and whom she was with, unless the activity is sleeping, grooming, “refused” (none of 

your business, etc.), or “don’t know.” For paid work, respondents are asked to report 

where they were but not who they were with.4

 The “who” codes for household members 

identify specific individuals. 

 

3

 Source “American Time Use Survey Jefferson Telephone Center Interviewer Manual,” September 13, 

2007 version. 

4

 In 2010, the ATUS started collecting information about who was present while respondents were 

working. 
7

After the time diary has been completed, the ATUS interviewers ask several summary 

questions that obtain information on childcare, paid work, and volunteering that cannot 

readily be obtained from the core time diary. These questions produce the “in your care” 

data discussed earlier. Note also that the “in you care” data are constructed to exclude any 

episodes involving childcare as a primary activity. 

Since the ATUS uses the CPS as a sampling frame, the ATUS data files contain some 

demographic information that was collected in the CPS, such as information about race 

and ethnicity. Demographic information on household members who were present 

during the final CPS interview appears in the ATUS data, except that information is 

excluded about household members who moved out between CPS and ATUS survey 

administration. For new household members, the ATUS collects only age, sex, and 

relationship to the respondent; for all household members, the age, sex, and relationship 

information provided in the CPS is verified and, if needed, updated. The ATUS updates 

the respondent's labor force status using an abbreviated version of the basic CPS 

questionnaire and also updates information on usual hours of work, class of worker, 

industry, occupation, earnings, and school enrollment. In addition, the ATUS collects 

basic labor market information (whether employed or not and full-time or part-time 

employment status) for the respondent’s spouse or unmarried partner. 

For this project, the Census Bureau coded secondary activities reported in the 2006 

ATUS data. Each secondary activity was coded by two independent coders, and was 

adjudicated when there were differences (as is done when coding primary activities). The 

coding was performed by the same team that codes the primary activities in the ATUS, so 

the coding of secondary activities is of high quality and is consistent with that for primary 

activities. The Census Bureau coders were asked to code only secondary activities 

mentioned first, so if a respondent listed three or four activities for a single time-use 

episode, the third and fourth were not coded and are not analyzed here. Fortunately, even 

in traditional time-use diaries with requested secondary activity reports, episodes with 

more than two activities provided for a single episode are rare, and even more rarely 

analyzed (e.g., Harvey 2006; Kitterod 2001), so the loss of information here should be 

minimal. 

It is important to note that ATUS interviewers do not record the starting and ending times 

of secondary activities. I follow the usual practice of using the duration of the primary 

activity, which implicitly assumes that the secondary activity was done for the entire 

period. 

The ATUS data can be analyzed at either the respondent- or episode-level. In the 2006 

data, there were 12,943 respondents who reported a total of 263,046 time-use episodes. 

The weighting variable TUFINLWGT is designed to correct for stratification of the 

sample. The weight can be applied at the respondent level to approximate figures for the 

civilian noninstitutional population over the age of 14 and, except where explicitly 

mentioned, that weight is applied to all figures below. The weight is also applied at the 

episode level for the same reasons, but note that respondents who report a greater number 

of episodes are implicitly weighted more heavily in those results. Therefore, episode-
8

level analyses should not be considered representative of the population, although it 

could be argued that weighting makes the resulting figures representative of the 

population of time-use episodes. 

The 2006 ATUS includes 17 major time-use categories, an 18th category that accounts for 

data that cannot be assigned a code, and 462 detailed categories.5 The major time-use 

categories are used in most of the following analyses. 

Respondent-Level Analyses

On a weighted basis, 29.3 percent of ATUS respondents report at least one secondary 

activity (3,955 out of 12,943 respondents). This rate seems high given that respondents 

are not asked to report secondary activities. But in time-use surveys that systematically 

collect secondary activities, the rate is close to 90 percent (Harvey 2006, p.199). The 

magnitude of this difference suggests that volunteered secondary activities in the ATUS 

are not comparable to traditional secondary activity reports. 

Table 1 shows the average time spent in the major activity categories in the ATUS, both 

as primary and secondary activities. On average, respondents reported a little over onehalf hour per day engaged in secondary activities, and fully half of that time was devoted 

to socializing, relaxing, and leisure, with just over 7 minutes spent on eating and 

drinking, and just under 5 minutes on household activities. As previously discussed, 

respondents reported spending less time in secondary activities under the volunteered 

approach than when they were asked to report secondary activities. When respondents 

were asked to report secondary activities, most reported over 3 hours (Harvey 2006, p. 

210). 

On the other hand, when secondary activities are requested, respondents may be more 

inclined to report short-duration sequential activities as secondary rather than taking the 

time to break them apart and report them as primary activities. A comparison of the data 

used here and of data from an earlier nationally-representative, time-use study that 

explicitly requested secondary activity reports suggests that this might be the case: the 

ATUS generates a greater mean number of episodes per respondent, even with extensive 

controls (see Drago and Stewart 2010). 

 

5

 For documentation, see the ATUS 2006 Coding Lexicon available at the ATUS web site: 

http://www.bls.gov/tus. 
9

Table 1: Average Cumulative Duration of Secondary and Primary Activities, Minutes 

 Secondary Primary 

Time-Use Category activities activities 

Personal care and sleep 0.93 563.69 

Household activities 4.84 109.33 

Caring for household members 0.79 26.93 

Caring for nonhousehold members 0.43 8.99 

Work 0.45 207.23 

Education 0.23 27.39 

Consumer purchases 0.17 24.25 

Professional and personal care services 0.06 5.18 

Household services 0.06 1.08 

Government services 0.00 0.63 

Eating and drinking 7.04 66.79 

Socializing, relaxing, and leisure 18.46 271.73 

Sports, exercise, and recreation 0.60 18.93 

Religious and spiritual activities 0.15 7.24 

Volunteer activities 0.11 7.78 

Telephone calls 0.46 7.06 

Travel 0.07 74.59 

Uncoded activities 1.20 11.20 

Total time per day 36.05 1440.00 

Sample size, N 12,943 12,943 

Source: 2006 ATUS. Note: The total time per day spent doing primary activities does not 

sum to 1440 minutes due to rounding. 

Time spent on primary activities has a very different distribution than that for secondary 

activities. Primary activities mainly involve personal care and sleep (over 9 hours); 

socializing, relaxing, and leisure (over 4.5 hours); work (just under 3.5 hours); household 

activities (almost 2 hours); travel (1.25 hours); and eating and drinking (just over 1 hour). 

Sleep and work are likely less often done while in engaging in other simultaneous 

activities or short sequential activities, again suggesting that the secondary activity data 

are picking up relevant activities. 

Turning to unpaid work, respondents spent just over 6 minutes per day in household 

activities (including caring for household and nonhousehold members) as a secondary 

activity. Only 1.02 minutes of this time was spent on childcare, which is already 

captured by the more inclusive “in your care” measure. Given the brief amount of time 

spent in household activities as a secondary activity–5.04 minutes after excluding 

childcare—it follows that the use of the secondary activity data, as currently collected, to 

improve estimates of household production would not contribute much time or value. 
10

The incidence of secondary activities is not distributed evenly across days of the week. 

Instead, the average respondent reports a low of 0.359 secondary activities for Tuesdays, 

rising to 0.436 activities on Wednesdays, 0.483 activities on Thursdays, with a peak at 

0.533 activities on Fridays, followed by a decline to 0.431 activities on Saturdays, with a 

mean of 0.414 activities on Sundays and Mondays. A negative binomial regression, with 

the number of secondary activities as the dependent variable and dummies for the diary 

day (omitting Wednesday), reveals that significantly fewer secondary activity episodes 

occur on Tuesdays and significantly more occur on Fridays, both at the 5 percent level.6

 

It is possible that respondents engage in more simultaneous or short-duration activities on 

Fridays; alternatively, respondents may be willing to take more time to do the interview 

and report secondary activities on Saturdays. Ultimately, it is impossible to know 

whether the latter possibility is correct because the reporting of secondary activities might 

either increase the reporting burden on respondents to the extent they are providing 

additional information, or decrease the burden if respondents use secondary reports as an 

alternative to providing more detailed primary activity data. 

We can, however, shed some indirect light on the reason for reporting secondary 

activities by comparing the characteristics of those who do and do not report secondary 

activities, as shown in Table 2. The figures are mainly percentages, and significance 

levels are from a simple logit regression predicting whether or not the respondent 

reported any secondary activity.7

 Significant differences suggest that women are more 

likely to report secondary activities and that respondents reporting these activities are 

around 5 years older, that they are only half as likely to be Hispanic, that they are around 

5 percentage points more likely to hold at least a bachelor’s degree, and that they worked 

around 3.5 hours per week less than respondents who did not report secondary activities. 

 

6

 Wednesday is omitted because the 0.436 average for that day is closest to the mean for the entire sample 

(0.439). Note that OLS performs poorly in the presence of many zero values, as is true here. Tobit could be 

applied, but this technique assumes that many of the zero values represent latent negative values, and it is 

not obvious what meaning negative values would convey. The negative binomial is a count regression 

method with a natural lower bound of zero. See Appendix table A1 for results. 

7

 Logit is a typical regression procedure when the dependent variable is dichotomous, as is the case here. A 

relevant alternative, the simple probit, yields identical signs and significance on the relevant variables. See 

Appendix table A2 for results. 
11

Table 2: Characteristics of Respondents who Do and Do Not Report Secondary Activities 

 One or more No secondary 

 secondary activities activities 

Characteristic reported reported 

Women (percent) 55.8** 49.8 

Any children (percent) 38.0 43.9 

Child under 6 years (percent) 16.1 20.0 

Married (percent) 59.2 57.4 

Age (years) 47.2** 42.7 

African-American (percent) 11.3 12.9 

Hispanic (percent) 7.5** 15.6 

Bachelor’s degree or higher (percent) 29.0** 23.8 

Employed (percent) 60.7 66.6 

Weekly work hours 22.4** 25.9 

Sample size, N 3,955 8,988 

Source: 2006 ATUS. ** for figure that is significantly larger in a logit predicting any 

secondary activity, 1% significance level. 

Women and those with high levels of education may be busier, which may lead these 

respondents to report more secondary activities. Consistent with this interpretation, the 

correlation between primary and secondary activity counts is 0.269. But consistent with 

this explanation, one would expect that respondents with children or those who work long 

hours would more often report secondary activities; but this is not the case.8 Further, it 

seems unlikely that older respondents are busier, yet an age quadratic in an otherwise 

identical linear OLS regression yields a maximum probability of reporting secondary 

activities among respondents over 80 years of age.9 It is at least possible that older 

respondents are willing to take the time to report their activities more completely.10 

Alternatively, some older respondents may suffer from recall difficulties and use 

secondary activity reports instead of providing more detailed primary activity reports. A 

disproportionate number of older respondents’ interviews are dropped from the ATUS 

sample because they spent too much time in uncodeable activities (for example, “don’t 

know”). That possibility suggests that the positive correlation between the number of 

primary and secondary activity episodes will be negative for older respondents. In fact, 

the correlation coefficient rises from 0.269 for the overall sample to 0.280 for the 1,460 

respondents over the age of 70 years, suggesting we can discount this alternative 

 

8

 Further, introducing an interaction between gender and children (i.e., a mother variable) did not yield a 

significant coefficient. 

9

 See Appendix table A3. 

10 Consistent with this possibility, the simple correlation between age and primary time spent on the 

category of socializing, relaxing, and leisure is a positive 0.280. A linear OLS regression with socializing, 

relaxing, and leisure time as the dependent variable, and an age quadratic as the dependent variable, yields 

an estimated minimum at age 35.1 years, suggesting the greatest amount of leisure and related time is 

available to respondents over the age of around 70 years. 
12

explanation. Also, note that there is no obvious explanation for why Hispanic 

respondents report secondary activities less often; perhaps the difference is cultural.11

An alternative way to examine the same issues lies in a regression of the cumulative daily 

time devoted to secondary activities on independent variables for the same characteristics 

listed in Table 2. Using the negative binomial method yields results very similar to those 

just discussed except that women are no more likely than men to report more time in 

secondary activities, while those who are employed report significantly less time in 

secondary activities (at the 1 percent level).12 

As a more direct test for whether busy respondents are associated with secondary 

activities, the regressions discussed above were replicated with the amount of leisure time 

as a primary activity serving as the independent variable. In both the logit for any 

activities and the negative binomial for cumulative time, relevant coefficients are 

significant at the 1 percent level.13 Simulations from OLS regressions suggest the effects 

are indeed positive though small; a 60-minute increase in leisure time raises the 

probability of reporting any secondary activity by 0.5 percent and expands the average 

amount of time spent on secondary activities by 3.4 minutes per day. However, it is 

important to note that leisure is historically associated with secondary activity reports, 

and this correlation may in fact represent the relative ease with which simultaneous 

activities can be performed while engaging in leisure activities. 

In sum, there is mixed evidence of secondary activity reports being associated with busy 

respondents, casting doubt on the validity of the data. 

Episode-Level Analyses 

Moving down from the level of the respondent, there are 6,046 secondary activity 

episodes, or a weighted 2.19 percent out of 263,046 total episodes. The average 

respondent reports 20.1 episodes per day, with 0.44 episodes having secondary activities. 

Somewhat surprising given the small number of secondary activities reported, nearly onethird of all respondents report at least one secondary activity. 

Table 3 shows the percentage of episodes accounted for by each of the major activity 

categories. The first column shows the distribution of secondary activities. The second 

column shows the distribution of primary activities for episodes in which a secondary 

activity was reported, and the last column shows the distribution of all primary activities. 

The distributions in the three columns were computed independently. I discuss the links 

between primary and secondary activities later. 

The distribution of episodes in Table 3 is similar to the distribution of time spent in the 

different activities shown in Table 1. Almost half of all secondary activity episodes are 

 

11 Drago and Stewart (2008) find that Hispanics are only around one-third as likely to report secondary 

activities when they are requested, although the difference is not statistically significant. 12 The negative coefficient on work hours only achieves significance at the 5 percent level in this 

regression, presumably because it is collinear with employment. See Appendix table A4 for results. 13 See Appendix tables A5and A6. 
13

socializing, relaxing or leisure, followed by eating and drinking, and household activities. 

The remaining time-use categories each account for less than 5 percent of secondary 

activity episodes. 

Table 3: Distribution of Secondary and Primary Activity Episodes, Percentages 

(weighted) 

 Primary 

 activities 

 with a 

 Secondary secondary Primary 

Time-Use Category activities activity activities 

Personal care and sleep 2.04 2.44 18.37

Household activities 11.96 13.39 13.23

Caring for household members 3.59 5.25 4.61

Caring for nonhousehold members 1.80 1.47 1.21

Work 1.35 3.08 5.92

Education 0.45 0.80 1.12

Consumer purchases 1.09 1.20 3.34

Professional and personal care 

services 0.16 0.23 0.58

Household services 0.16 0.10 0.12

Government services 0.02 0.05 0.05

Eating and drinking 20.06 22.59 10.27

Socializing, relaxing, and leisure 49.33 41.74 16.15

Sports, exercise, and recreation 1.08 1.38 1.19

Religious and spiritual activities 0.57 0.30 0.50

Volunteer activities 0.41 0.72 0.50

Telephone calls 1.24 1.45 1.15

Travel 1.02 2.37 20.82

Uncoded activities 3.68 1.44 0.88

Total 100.00 100.00 100.00

Sample size, N 6,046 6,046 263,286

Source: 2006 ATUS. 

There are, however, marked differences in the distribution of primary activities 

depending on whether or not a secondary activity was reported. When the respondent 

reports a secondary activity, over 40 percent of related primary activities fall into the 

category of socializing, relaxing, and leisure, followed by eating and drinking, and then 

by household activities. In the overall sample, the most frequent activity is travel, 

followed by personal care and sleep, with the three categories just discussed trailing those 
14

two.14 It seems likely that socializing, relaxing, and leisure; eating and drinking; and 

household activities lend themselves to both truly simultaneous and short-duration, 

sequential activities, so we cannot ascertain whether the volunteered method of secondary 

activity data collection focuses respondents on truly simultaneous activities as secondary. 

I return to this issue in the analysis of detailed time-use categories below. 

One possible linkage between specific primary activities and secondary activity reports 

lies in the pre-codes available to ATUS interviewers for a set of 15 detailed primary 

activities. Because the pre-codes speed up the process of data entry, it is possible that 

interviewers will be more likely to collect secondary activity reports for activities that can 

be pre-coded. Table 4 shows that 125,038 (or 47.5 percent) of episodes were coded using 

a pre-code. If the use of pre-codes leads to greater reporting of secondary activities, the 

percentage of secondary activity episodes reported during pre-coded activities should be 

larger. In fact, only 2,544 of 6,046 secondary activity episodes, or 42.1%, have precoded primary activity reports. Further, in over 2,100 of those episodes the primary 

activities were pre-coded as watching television or eating and drinking, activities which 

are traditionally associated with secondary activities.15 Therefore, it seems reasonably 

safe to conclude that the use of pre-codes does not affect the reporting of secondary 

activities. 

 

14 In the ATUS, if a respondent reports doing simultaneous activities that involve a travel episode, the 

travel will be collected and coded as the respondent's primary activity. For example, if someone reports 

driving to work and talking on the phone at the same time, the episode would be coded as travel. 

15 For all but one of the sleep episodes where a secondary activity was reported, the latter activity involved 

watching “television and movies (not religious).” 
15

Table 4: Pre-coded Primary Activities and Secondary Activity Episodes 

 

Number 

of Number of 

Percent 

of 

 pre-coded pre-coded pre-coded 

 primary primary Total primary 

 activities activities number of activities 

 with a without a pre-coded with a 

Primary activity secondary secondary primary secondary 

description activity activity activities activity 

Sleeping 9 27,652 27,661 0.03 

Grooming (Self) 45 16,791 16,836 0.27 

Watching television 902 18,683 19,585 4.61 

Working, main job 40 9,907 9,947 0.40 

Working, second job 1 392 393 0.25 

Preparing meals and snacks 137 10,798 10,935 1.25 

Eating and drinking 1,200 24,811 26,011 4.61 

Cleaning the kitchen 53 3,886 3,939 1.35 

Laundry 130 3,311 3,441 3.78 

Grocery shopping 4 2,099 2,103 0.19 

Attending religious services 0 1,008 1,008 0.00 

Paying household bills 3 46 49 6.12 

Caring for animals and pets 20 2,208 2,228 0.90 

Do not know 0 853 853 0.00 

Refusal 0 49 49 0.00 

Total 2,544 122,494 125,038 23.76 

Source: 2006 ATUS. 

Splitting out childcare from the two care categories (Caring for and helping household 

members and Caring for and helping nonhousehold members) reveals that 4.71 percent of 

all primary activity episodes, but a slightly lower 4.37 percent of secondary activity 

episodes, were childcare. 

Table 5 shows the distribution of where codes for episodes that have secondary activities 

and for all episodes. The “home or yard” category accounts for just under 40 percent of 

all episodes, but almost three-quarters of secondary activity episodes. The only other 

location that accounts for at least 5 percent of secondary activity reports is someone 

else’s home. These findings are consistent with the interpretation that secondary activity 

data are to some extent reflecting the messiness of home life. 
16

Table 5: The Location of Primary and Secondary Activity Episodes, Percentage of All 

Episodes 

 Secondary 

 All activity 

Location Episodes episodes 

Home or yard 39.36 72.11 

Unknown1 18.18 1.10 

Car, truck, or motorcycle (driver) 14.28 1.74 

Workplace 7.05 4.67 

Car, truck, or motorcycle (passenger) 3.57 0.00 

Other place 3.19 3.97 

Someone else’s home 3.14 7.39 

Other store or mall 2.19 1.24 

Restaurant or bar 1.88 3.55 

Walking 1.80 0.00 

School 1.60 1.11 

Other categories, accounting for 

 <1% of the total 3.76 3.12 

Total 100.00 100.00 

Sample size, N 263,286 6,046 

1

 Location data are not collected for times respondents were sleeping, grooming, doing 

personal activities, and when they didn't know or refused to provide information about 

what they were doing. 

Source: 2006 ATUS. 

Information about who respondents were with is not collected for times they reported 

sleeping, grooming, and a few other personal activities, which together account for 24.1 

percent of all episodes. These activities rarely generate secondary activities, and whowith information is missing for only 3.7 percent of episodes with secondary activities. 

Ignoring episodes during which the who-with information was not collected, figures for 

who respondents were with during all episodes and during secondary activity episodes 

are shown in Table 6. Note that these figures do not sum to 100 percent because multiple 

individuals may be present during an activity. Respondents were slightly less likely to be 

alone while engaging in secondary activities (a 3 percentage point divergence), and this 

difference is explained by the more frequent presence of either a partner or spouse or 

other adult during the episode. 

Children were only about 2 percentage points less likely to be present during secondary 

activity episodes. This result does not, however, imply that childcare is rarely done as a 

secondary activity, since a full 34.8 percent of “in your care” episodes occur when the 

child is not in the same location (e.g., is instead in the next room or outdoors). That time 

is, as noted earlier, linked to secondary activity reports. 
17

In earlier U.S. time-diary surveys, alone time accounted for a smaller fraction of 

episodes—between 22.7 and 36.6 percent (Harvey 2006, p. 208). Although other 

explanations might be plausible, it is possible that the greater incidence of being alone 

during secondary (and perhaps primary) activity episodes in the ATUS reflects the 

dramatic growth of single-person households in recent decades (Fields and Casper 2000). 

Table 6: Who Respondents were with as a Percentage of Non-missing Episodes 

 All Secondary 

 activity activity 

Who with episodes episodes 

Alone 45.96 42.78 

With partner or spouse 21.49 25.96 

With child 22.42 20.39 

With partner or spouse and child 7.03 7.20 

With other adult 22.92 27.51 

Sample size, N 203,937 5,852 

Source: 2006 ATUS. Note that percentages do not add up to 100 because respondents 

can be with people from more than one category. 

The final analyses connect primary and secondary activities across the major time-use 

categories. For the most-frequently-reported secondary activities, I examine detailed 

time-use categories for both secondary and primary activities. 

The major time-use categories for secondary activity episodes were matched with those 

for primary activities, resulting in an 18-by-18 matrix with 6,046 unweighted 

observations. I restrict my attention to the seven cells that have at least 2 percent of these 

episodes (more than 130 observations each). These cells account for 4,143, or about twothirds, of the 6,046 secondary activity episodes. The cells are listed in descending order 

of prevalence in Table 7. Considering the number of episodes, linkages between 

socializing, relaxing, and leisure, and eating and drinking are by far the most common, 

and comprise over half of all secondary activity episodes. Household activities as either 

secondary or primary account for around one-sixth of these episodes, and caring for 

household members covers a small fraction of the episodes. 

The last column of Table 7 reports the average amount of time per day spent on the 

linked activities. Recalling that secondary activity reports account for just over 36 

minutes per day, on average, the figures show that around one-quarter of that time is 

accounted for by leisure as either a primary or a secondary activity. Indeed, over half of 

all secondary activity time (18.43 minutes) can be attributed to some mixture of leisure 

and eating and drinking. 
18

Table 7: Related Secondary and Primary Activity Episodes, Number of Episodes and 

Cumulative Duration 

 Related Number Average 

Secondary primary of minutes 

activity activity episodes per day 

Socializing, Relaxing, Eating and 

and Leisure Drinking 1,108 4.25 

Socializing, Relaxing, Socializing, Relaxing, 

and Leisure and Leisure 1,042 8.82 

Eating & Socializing, Relaxing, 

Drinking and Leisure 899 5.47 

Socializing, Relaxing, Household 

and Leisure activities 351 2.08 

Household Household 

activities activities 318 2.01 

Household Socializing, Relaxing, 

activities and Leisure 273 2.15 

Socializing, Relaxing, Caring for household 

and Leisure members 152 0.28 

 Total sample size, N 6,046 12,943 

Source: 2006 ATUS. 

In two instances, the primary and secondary activities are in the same major category. 

Earlier in Table 1, we saw that respondents spent just under 5 minutes per day in 

household activities. In calculations of the time spent in unpaid work, the 2 minutes per 

day when household activities were reported as both the primary and secondary activities 

must be subtracted from this total so that it is not double-counted. 

For a more fine-grained look at linkages between the secondary and linked primary 

activities, I analyzed detailed activity categories where the relevant major categories for 

the secondary activity are either: household activities; eating and drinking; or 

socializing, relaxing, and leisure, as shown in Table 8. These three broad categories not 

only figure prominently in the analysis presented in Table 6, but are also most prevalent 

in terms of both the cumulative amount of time involved (see Table 1), and the number of 

episodes reported (see Table 3). Note that, for the secondary activity reports, eating and 

drinking is both a broad activity category and a single detailed category. For simplicity, 

detailed categories accounting for less than 5 percent of relevant episodes are excluded 

from the table. 
19

A total of 3,014 secondary activity reports are categorized as socializing, relaxing, and 

leisure, with watching television, socializing, and reading accounting for most of the 

episodes. Related primary activities involve eating and drinking, watching television, 

socializing, and reading. For the 1,190 episodes of eating and drinking as a secondary 

activity, primary activities mainly involve watching television, socializing, and reading. 

For the 757 episodes of household activities as secondary, detailed activities are largely 

comprised of doing laundry; interior cleaning; food and drink preparation; care for pets; 

household and personal organization and planning; household and personal mail and 

messages excluding email; and sewing, repairing, or maintaining textiles. The main 

associated primary activities in this case include watching television, interior cleaning, 

socializing, and doing laundry. 

Table 8: Detailed Secondary Activity Episodes and Related Primary Activities 

 

Secondary Related 

activity Detailed secondary activity primary activity 

Socializing, Television (51.9%) Eating and drinking (38.8%) 

Relaxing, and Socializing (18.9%) Television (9.3%) 

Leisure Reading (11.9%) Socializing (8.8%) 

(3,014 episodes) Reading (13.5%) 

Eating and Eating and drinking Television (25.5%) 

Drinking Socializing (24.6%) 

(1,190 episodes) Reading (13.5%) 

Household Laundry (21.6%) Television (22.8%) 

activities Interior cleaning (14.8%) Interior cleaning (10.2%) 

(757 episodes) Food and drink preparation (11.5%) Socializing (9.2%) 

 Care for pets (9.3%) Laundry (5.6%) 

 Household and personal 

 organization and planning (8.0%) 

Source: 2006 ATUS. 

Overall, the analysis of detailed categories suggests that secondary activities largely 

revolve around watching television and eating and drinking, either as a secondary or 

associated primary activity. 

In terms of the validity of the data, we need to know whether these activities are more 

often performed as truly simultaneous activities, or instead in short duration, sequential 

episodes. Unfortunately, both watching television and eating and drinking are subject to 

either interpretation. We simply have no way of knowing which is the case. 
20

Conclusion

The quotation from Alexander Szalai provided earlier in this report suggested that the 

ATUS should have taken a more traditional approach and explicitly requested secondary 

activity data from respondents. This analysis has examined the secondary activity reports 

collected in the 2006 ATUS. In some ways, the volunteered secondary activity data seem 

to mimic traditionally-requested secondary activity reports. Most secondary activities 

occur in the home and women are more likely to report secondary activities, which 

together reflect the messiness of home life and the prominent role that women continue to 

play in the home. Consistent with expectation, more-highly-educated respondents are 

also more likely to report secondary activities. When secondary activities are reported, 

the most common activities are socializing, relaxing, and leisure; eating and drinking; and 

household activities. But, contrary to expectations, respondents who work longer hours 

were less likely to report secondary activities, while respondents who are over the age of 

70 were more likely. 

One reason for collecting data on secondary activities is to obtain a better measure of 

household production for national income and product accounts. However, very little 

household production beyond childcare was identified in this analysis. Further, the little 

time that was identified – around 5 minutes – was mainly done in conjunction with 

household activities as a primary activity, or with socializing, relaxing, and leisure, 

suggesting that the 5 minutes would need to be discounted substantially before 

incorporating that time into satellite accounts. 

The results presented here make it clear that ATUS respondents report secondary 

activities far less frequently and secondary activities account for far less time compared 

with traditionally-collected secondary activity reports. Thus, the secondary activity data 

that are currently collected in the ATUS are of limited value. Given the low quality of 

these data, it is hard to make the case for incurring the expense of coding the data for 

other years and incorporating them into analyses. If the data used for this study were 

made available from the BLS, at a minimum, researchers would be wise to treat the data 

with caution. 

Would it make sense to start systematically collecting secondary activities in the ATUS? 

Collecting these data would provide richer information about how Americans spend their 

time. It would also provide a more complete picture about the amount of time spent in 

household activities, which would be useful for constructing satellite national income and 

product accounts to measure the value of household production. The amount of time 

involved is likely to be relatively small – Harvey’s results suggest perhaps 15 minutes per 

day. In the grand scheme of economic production, 15 minutes of unpaid work per day, 

applied to an entire adult population over an entire year, is arguably nontrivial. However, 

in a comparison of the data used here with results from an earlier nationallyrepresentative time-use survey, Drago and Stewart (2010) conclude that the relevant 

undervaluation of housework due to the ATUS not explicitly requesting secondary 

activity data involves the economic value of only around one minute per day.16

 

16 The much smaller figure arises from three factors: 1) much housework as a primary activity is performed 

in conjunction with leisure, so should be discounted, 2) around half of housework as a secondary activity is 
21

The major danger of changing the ATUS to systematically collect secondary activities is 

that it may change the way that primary activities are reported. Two analyses suggest this 

danger is potentially significant. Kitterod (2001) analyzed two days of Norwegian timeuse diaries wherein secondary activity reports were explicitly requested of respondents 

only on the second day. She found differences in the pattern of primary activity reports 

across the two days, and suggests the data are not strictly comparable. Further, a 

comparison of the ATUS data analyzed here, and of 1998-1999 U.S. time-use data 

including traditional secondary activity reports, suggest not only that primary activity 

reports are altered by the inclusion of explicit secondary activity options, but also that the 

quality of primary activity reports may be compromised in the process (Drago and 

Stewart 2008). The main issue is that if respondents are asked to report secondary 

activities, they may report short-duration primary activities as secondary. For example, 

someone who spends 20 minutes cooking, 5 minutes talking on the phone, and then 

another 20 minutes cooking may report a single 45-minute episode of cooking with the 

secondary activity of talking on the phone. However, evidence in the Drago and Stewart 

study suggests that the ATUS practice of encouraging respondents to break apart these 

activities mitigates this problem. In the Kitterod (2001) study, respondents were given 

leave-behind diaries, so there was no interviewer to prompt respondents to break these 

activities apart. If such a change is seriously contemplated, it would be wise to begin with 

a pilot, wherein some respondents are and others are not requested to provide secondary 

activity reports. If that pilot demonstrated that the quality of primary activity reports 

would not be substantially impaired, it might then be reasonable to expand secondary 

activity data collection to include all future ATUS respondents. 

 performed in connection with housework as a primary activity, and it would not make sense to double the 

value of housework when it is performed as both a primary and secondary activity, and 3) much of the 

remaining housework as a secondary activity is related to leisure as a primary activity, so it should also be 

discounted. 
22

REFERENCES

Allard, M.D., S. Bianchi, J. Stewart and V.R. Wight. 2007. “Comparing Childcare 

 Measures in the ATUS and Earlier Time-Diary Studies.” Monthly Labor Review 

130:27-36. 

Bianchi, S.M., J.P. Robinson and M.A. Milkie. 2006. Changing Rhythms of American 

Family Life. New York, NY: Russell Sage.

Budig, Michelle and Nancy Folbre. 2004. “Child Care vs. Child-Minding: Measuring 

Activities, Responsibilities, and Time,” in Family Time: The Social Organization 

of Care, Nancy Folbre and Michael Bittman, eds. New York: Routledge. 

Drago, Robert. 2007. Striking a Balance: Work, Family, Life. Boston: Dollars and Sense. 

_______ and Jay Stewart. 2010. “Time-use Surveys: Issues in Data collection on 

Multitasking.” Monthly Labor Review 133:17-31. 

Fields, Jason, and Lynne M. Casper. 2000. “America’s Families and Living 

Arrangement: Population Characteristics,” Current Population Reports, P20-537. 

Washington, DC: U.S. Bureau of the Census. 

Folbre, Nancy. 2001. The Invisible Heart: Economics and Family Values. New York: 

Free Press. 

Folbre, Nancy and Jayoung Yoon. 2008. “The Value of Unpaid Child Care in the 

 U.S. in 2003,” in How Do We Spend Our Time? Evidence from the 

American Time Use Survey, ed. Jean Kimmel. Kalamazoo, MI: W.E. Upjohn 

Institute, 33-58. 

Harvey, Andrew S. 2006. “Nonmarket Production and Historical Time-Use Data: 

Potential and Issues,” Time Use Resarch Program, Saint Mary’s University, 

Halifax, Nova Scotia, Canada, May 15. 

Kitterod, Ragni Hege. 2001. “Does the Recording of Parallel Activities in Time Use 

Diaries Affecct the Way People Report Their Main Activities?” Social Indicators 

Research 56: 145-178. 

Landefeld, Steven J., Barbara M. Fraumeni, and Cindy M. Vojtech. 2009. "Accounting 

for Nonmarket Production: A Prototype Satellite Account Using the American 

Time Use Survey." Review of Income and Wealth 55: 205-225. 

Reid, Margaret. 1934. Economics of Household Production. New York: John Wiley & 

Sons. 

Szalai, Alexander. 1972. The Use of Time. The Hague: Mouton. 
23

APPENDIX 

Table A1: Negative Binomial Regression - Number of Secondary Activities 

Variable Coefficient Std Error p-value

Sunday -0.0442 0.0714 0.5360

Monday -0.0536 0.0893 0.5480

Tuesday -0.1957 0.0872 0.0250

Thursday 0.1021 0.0845 0.2270

Friday 0.1994 0.0870 0.0220

Saturday -0.0133 0.0713 0.8520

Constant -0.8295 0.0593 <0.0001

Table A2: Logistic Regression – Any Secondary Activities 

Variable Odds Ratio Std Error p-value 

Woman 1.1763 0.0643 0.0030

Any children 1.0339 0.0740 0.6420

Child under 6 years 0.9300 0.0679 0.3200

Married 0.9472 0.0567 0.3640

Age 1.0273 0.0088 0.0020

Age_squared 0.9998 0.0001 0.0350

Employed 1.0767 0.1044 0.4460

African-American 0.8756 0.0626 0.0630

Hispanic 0.4972 0.0451 <0.0001

Bachelor’s degree or 

higher 1.2780 0.0785 <0.0001

Weekly work hours 0.9921 0.0021 <0.0001
24

Table A3: Linear Regression – Any Secondary Activities 

Variable Coefficient Std Error p-value

Woman 0.0323 0.0110 0.0030

Any children 0.0055 0.0141 0.6970

Child under 6 years -0.0135 0.0138 0.3290

Married -0.0098 0.0122 0.4250

Age 0.0049 0.0017 0.0050

Age_squared <0.0001 <0.0001 0.0930

Employed 0.0144 0.0199 0.4710

African-American -0.0191 0.0082 0.0190

Hispanic -0.1183 0.0135 <0.0001

Bachelor’s degree or 

higher 0.0515 0.0130 <0.0001

Weekly work hours -0.0016 0.0004 <0.0001

Constant 0.1722 0.0373 <0.0001

Table A4: Negative Binomial – Cumulative time for Secondary Activities 

Variable Coefficient Std Error p-value

Woman 0.0861 0.0574 0.1340

Any children -0.0532 0.0815 0.5140

Child under 6 years -0.0906 0.0845 0.2830

Married -0.0836 0.0633 0.1860

Age 0.0266 0.0092 0.0040

Age_squared -0.0002 0.0001 0.0220

Employed -0.3212 0.0999 0.0010

African-American -0.0303 0.0878 0.7300

Hispanic -0.6308 0.0935 <0.0001

Bachelor’s degree or 

higher 0.1897 0.0598 0.0020

Weekly work hours -0.0044 0.0022 0.0460

Constant 3.2073 0.2168 <0.0001

Table A5: Logistic Regression – Any Secondary Activities 

Variable Odds Ratio Std Error p-value

Total Leisure Time 0.0004 0.0001 <0.0001

Constant -0.9979 0.0431 <0.0001

Table A6: Negative Binomial – Cumulative time for Secondary Activities 

Variable Coefficient Std Error p-value

Total Leisure Time 0.0015 0.0002 <0.0001

Constant 3.1419 0.0557 <0.0001