OSIPP Discussion Paper: DP-2015-E-002

Home appliances and gender gap of time spent on unpaid housework:
evidence using household data from Vietnam

August 04, 2015
Tien Manh Vu†
Japan Society for the Promotion of Science
Osaka University[Keywords] Home appliances, Gender gap, Housework, Time use, Housework division[JEL Code] D13, J16, J22[Abstract] We examined the gender gap between wives and husbands with regard to timespent on unpaid housework and the interaction terms between the appearance of home
appliances and gender among 36,480 Vietnamese households. We found the gender gap oftime is persistent regardless of the number of coresiding children, age cohorts, household size
and income, and working status of the couples. Wives spent 40.3–58.6 minutes more on
unpaid housework daily. In household fixed-effect estimations, we found the interaction
terms had a positive relationship with the time spent on unpaid housework. Where a gas
cooker was available, the time spent on unpaid housework of the wife was 16.9 minutes morethan that of her husband on a daily basis. However, we did not detect any significant
interaction effects among pure dual-wage earners, and where husbands are aged less than 26
years.

______________________________________________________________________† Corresponding author: Tien Manh Vu
Osaka School of International Public Policy, Osaka University
1–31 Machikaneyama, Toyonaka, Osaka 560–0043, JAPAN.
Tel/Fax: +81-(0)6-6850-5656. E-mail: t-vu@osipp.osaka-u.ac.jp.
[Acknowledgments] I thank Hisakazu Matsushige of Osaka University and the participants of theInternational Association for Feminist Economics Annual Conference held in Berlin, Germany, in July
2015 for the valuable comments and suggestions. I acknowledge the financial support from the JSPS
KAKENHI Grant number A26043110 from the Japanese Society for the Promotion of Science.

1

1 Introduction“Stoves were labor-saving devices but the labor that they saved was male.”
Cowan (1983, page 61)
Our study examines whether the gender gap of time spent on unpaid housework exists andwhether the appearance of home appliances reduces this gender gap between husbands andwives in Vietnam. We chose Vietnam because its transitioning economy contains bothindustrial and agricultural societies. Thanks to trade that is more open and to rising income
levels, the lifestyle of Vietnamese households is improving1. In 2008, approximately 44.6%,
11.9%, and 31.1% of households owned a gas cooker, washing machine, and fridge,
respectively 2 . However, this implies that the majority of households lived without theseappliances. There has also been a shift from agricultural to nonagricultural work. For example,
55.1% of workers aged 15 years and over were employed in agriculture, forestry, and fisheryin 2005, but this number had fallen to 52.3% in 20083. Therefore, the allocation of time spent
on work, unpaid housework, and leisure has changed. In addition, the total fertility rate fell
from 2.25 to 2.08 children during 2001–20084. Thus, women had an increasing amount oftime for paid work, leisure time, and unpaid housework over this period.
The majority of the literature in this area analyzes the negative relationship between
time on paid work and unpaid housework among working couples. Hersch and Stratton(1997), Kimmel and Connelly (2008) and Bloemen (2010) are examples of such studies.
Hersch (2009) finds that men substitute less paid work for unpaid housework than women do.
Gronau (1977) shows that an increase in the wife’s wage rate results in more paid working
hours, less housework, and less leisure. Hersch and Stratton (1994) indicate that the gender
gap on unpaid housework is due to the different wage rates of husbands and wives. Wales andWoodland (1997) further estimate the response of housework hours to the ratio of the wage
rates. Gough (2011) finds unemployed individuals spend three to seven hours more per week
on housework than when employed; and this increase is twice as large for women than formen. However, no study has investigated the case when both do not work, nor addressed thecase where couples mix paid work with agricultural work and/or a home business.

1

Vietnam joined the World Trade Organization in 2006 and experienced average annual GDP growth of over
5% from 1990 to 2008 (http://www.gso.gov.vn/default_en.aspx?tabid=468&idmid=3&ItemID=12979).
2
Authors’ calculations.
3
See http://www.gso.gov.vn/default_en.aspx?tabid=467&idmid=3&ItemID=12889.
4
See http://www.gso.gov.vn/default_en.aspx?tabid=467&idmid=3&ItemID=12913.

2

Although how husbands and wives allocate time on unpaid housework varies acrosscountries, husbands tend to do less. Ueda (2005) shows that an hour of Japanese husbands’
housework does not perfectly substitute for an hour of wives’ housework. Bloemen et al.
(2010) find that Italian husbands do less housework. Hersch and Stratton (1994) find thatwives employed full time spend more time on both housework and paid work than theirhusbands do because women earn less. Hersch and Stratton (1994) find that if the genderwage gap declines, time spent on housework will be closer to equal. Folbre and Nelson (2000)
find that if wives spend more time on paid work, husbands are less likely to increase timespent on unpaid housework to compensate. However, they did not consider the appearance ofhome appliances.
The explanations for the reallocation of time between husbands and wives vary andare not simple. Stratton (2012) indicates that men dislike housework. Thus, wives have tocompensate. Kroska (2003) reports that women find baby care and laundry-related activities
to be “good, potent, and active” and preparation of meals to be “particularly powerful,” butdislike washing dishes more than men do. Poortman and Lippe (2009) show that women tend
to favor cleaning, cooking, and childcare more than men do. Beblo and Robledo (2008) showthat husbands have more leisure time because they are Stackelberg leaders in sequential
private provision games. Analyzing French workweek reduction policy, Goux et al. (2014)
find that husbands of policy-eligible woman tend to reduce their paid work time, while thewives show little response if their husband was in the target group of the policy.
In this study, we first investigate the time allocation between husbands and wives on
unpaid housework and paid work using seemingly unrelated regressions. In the main analysis,
we use household fixed-effect models to estimate the time gap on unpaid housework and thenthe interaction terms between the appearance of home appliances and gender. We find thegender gap of time is persistent and around 40.3–58.6 minutes per day, even among dualnonworking couples. We also find a positive nexus between the appearance of home
appliances (gas cooker) and an increase in the time gap indicating less time on unpaid
housework for men. We argue that the participation of the husband in specific unpaid
housework tasks could be one of the main reasons for this nexus.
Our study extends the previous studies in several ways. To the best of our knowledge,
this is the first empirical study analyzing the interaction between home appliances and thegender gap of time spent on unpaid housework. By eliminating the time-invariant factors inhousehold fixed-effect models, we can measure the real “natural” gender gap between

3husbands and wives. Furthermore, we first consider the interaction terms for more than 26
types of household composition.
This paper proceeds as follows. The next section describes the data. Section 3
illustrates how we estimate the gender gap of time spent on housework using different
samples. In Section 4 we present the results, and Section 5 presents the conclusions anddiscussion.

2 DataWe use the Vietnamese Household Living Standard Survey 2008 (VHLSS 2008). This
provides cross-sectional and country-representative data from the General Statistics Office ofVietnam (GSO) using a two-stage stratified sampling method. The VHLSS 2008 design is
identical to the Living Standards Measurement Studies by the World Bank. VHLSS 2008 is
the latest survey containing information about housework from 45,945 households comprising289,948 individuals. In the VHLSS, there are two questions: one about whether individuals
do housework and if the answer is yes, the other concerns how many hours per day theindividuals spent on housework on average during the previous 12 months. VHLSS 2008
defines housework as activities such as cleaning, shopping, cooking, washing clothes,fetching water and wood, and repairing tools. We refer to this definition as routine unpaid
housework. The survey includes information about the availability of home appliances suchas freezers, vacuum cleaners, washing machines and driers, gas cookers, rice cookers, andmicrowave ovens.
We use information on time spent on unpaid housework and the presence of home
appliances as the main variables. We consider the head and the head’s spouse as the husband
and wife of the family in our analysis. After excluding households in which the head does nothave a spouse, we have 36,480 households. The descriptive statistics of our data are presented
in Tables 1 and 2.
[Insert Tables 1 and 2 here]

3 Empirical methods
We estimate two econometric models. The first are seemingly unrelated regressions (SURs)
for the decisions of husbands and wives on time spent on paid work and unpaid housework.

4The second are household fixed-effect models (HHFEs) for analyzing the gender gap on timespent on unpaid housework.
We assume that both husband 𝑗 and wife 𝑖 in a household 𝑘 allocate their time
simultaneously between paid work and unpaid housework in four reduced-form SURs as
follows.
𝑃𝑎𝑖𝑑 𝑤𝑜𝑟𝑘𝑖𝑘 = 𝛼1 𝑃𝑎𝑖𝑑 𝑤𝑜𝑟𝑘𝑗𝑘 + 𝛼2 𝑈𝑛𝑝𝑎𝑖𝑑 ℎ𝑜𝑢𝑠𝑒𝑤𝑜𝑟𝑘𝑗𝑘 + 𝛼3 𝑈𝑛𝑝𝑎𝑖𝑑 ℎ𝑜𝑢𝑠𝑒𝑤𝑜𝑟𝑘𝑖𝑘 + 𝛼4 𝑋𝑖𝑘 + 𝛼5 𝑋𝑗𝑘 +𝛼6 𝐷𝑘 + 𝜀𝑖𝑘 ,(1)𝑃𝑎𝑖𝑑 𝑤𝑜𝑟𝑘𝑗𝑘 = 𝛽1 𝑃𝑎𝑖𝑑 𝑤𝑜𝑟𝑘𝑖𝑘 + 𝛽2 𝐻𝑜𝑢𝑠𝑒𝑤𝑜𝑟𝑘𝑖𝑘 + 𝛽3 𝐻𝑜𝑢𝑠𝑒𝑤𝑜𝑟𝑘𝑗𝑘 + 𝛽4 𝑋𝑖𝑘 + 𝛽5 𝑋𝑗𝑘 + 𝛽6 𝐷𝑘 + 𝜖𝑗𝑘 , (2)𝑈𝑛𝑝𝑎𝑖𝑑 ℎ𝑜𝑢𝑠𝑒𝑤𝑜𝑟𝑘𝑖𝑘 = 𝛾1 𝑃𝑎𝑖𝑑 𝑤𝑜𝑟𝑘𝑗𝑘 + 𝛾2 𝑈𝑛𝑝𝑎𝑖𝑑 ℎ𝑜𝑢𝑠𝑒𝑤𝑜𝑟𝑘𝑗𝑘 + 𝛾3 𝑃𝑎𝑖𝑑 𝑤𝑜𝑟𝑘𝑖𝑘 + 𝛾4 𝑋𝑖𝑘 + 𝛾5 𝑋𝑗𝑘 +𝛾6 𝐷𝑘 + 𝜂𝑖𝑘,

(3)

𝑈𝑛𝑝𝑎𝑖𝑑 ℎ𝑜𝑢𝑠𝑒𝑤𝑜𝑟𝑘𝑗𝑘 = 𝜔1 𝑃𝑎𝑖𝑑 𝑤𝑜𝑟𝑘𝑖𝑘 + 𝜔2 𝑈𝑛𝑝𝑎𝑖𝑑 ℎ𝑜𝑢𝑠𝑒𝑤𝑜𝑟𝑘𝑖𝑘 + 𝜔3 𝑃𝑎𝑖𝑑 𝑤𝑜𝑟𝑘𝑗𝑘 + 𝜔4 𝑋𝑖𝑘 + 𝜔5 𝑋𝑗𝑘 +𝜔6 𝐷𝑘 + 𝜃𝑗𝑘 .

(4)

Each individual is required to consider his/her time spent on paid work and unpaid
housework as well as that by their partner. The decision must be based on an individual’scharacteristics (𝑋𝑖𝑘 ), their partner’s characteristics (𝑋𝑗𝑘 ) and those of the household (𝐷𝑘 ). Thus,𝐸(𝜀𝑖𝑘 , 𝜖𝑗𝑘 , 𝜂𝑖𝑘 , 𝜃𝑗𝑘 |𝑋) = 𝜎𝑘 with a zero mean across households. Where the couples are notworking, the SURs become two equations, (3) and (4).
We use HHFEs to analyze the gender gap in time spent on unpaid housework. For
each household, we assume the time spent on unpaid housework depends mainly on (a) the
variation that covariates with the gender of the individuals, (b) individuals’ characteristics thatvary between the husband and the wife (𝑋𝑖𝑘 ), and (c) the preference or sharing rules or any
factors that remain constant over time within the household (𝐻𝑜𝑢𝑠𝑒ℎ𝑜𝑙𝑑𝑘 ).
𝑈𝑛𝑝𝑎𝑖𝑑 ℎ𝑜𝑢𝑠𝑒𝑤𝑜𝑟𝑘𝑖𝑘 = 𝜑1 𝑆𝑒𝑥𝑖𝑘 + 𝜑2 𝐻𝑜𝑚𝑒 𝑎𝑝𝑝𝑙𝑖𝑎𝑛𝑐𝑒𝑠𝑘 ∗ 𝑆𝑒𝑥𝑖𝑘 + 𝜑3 𝑋𝑖𝑘 + 𝜑4 𝑋𝑖𝑘 ∗ 𝑆𝑒𝑥𝑖𝑘 + 𝜑5 𝐷𝑘 ∗𝑆𝑒𝑥𝑖𝑘 + 𝜑6 𝐻𝑜𝑢𝑠𝑒ℎ𝑜𝑙𝑑𝑘 + 𝜗𝑖𝑘(5)

The time-invariant factors are captured by a dummy for each family. We use the Stata
command areg in our analysis with 34,679 dummies (𝐻𝑜𝑢𝑠𝑒ℎ𝑜𝑙𝑑𝑘 ). Thus, the coefficient 𝜑1shows the “pure” gender gap in time spent on unpaid housework. Meanwhile, the interactions
between the variables of interest with 𝑆𝑒𝑥𝑖𝑘 show the marginal gap of time spent on housework
between wife and husband if the variables of interest change by one unit, holding all otherfactors constant within the household.

5The main characteristics of individuals are described in Tables 1 and 2. Later labeled
Absence–w/h (Ill day–w/h), “absence” (“ill day”) indicates the total number of days in the 12months prior to the survey that the wife/husband was absent (ill) and unable to do routine
work. We construct four dummies for the number of coresiding children by age cohort from
0–6, 7–12, 13–17, and for couples coresiding without any children.
We also add dummies for the appearance of home appliances in the household as wellas construct the first principal component of the six appliances. We notice that pure dualwage earners are people who work for a salary, but who are not involved in any agricultural
work for a family business. This is done to distinguish them from dual-wage earners who
might do both of these types of work.
We divide the data into six main categories as a robustness check of the gender gap,
and of the interaction between the variables of interest and gender. These categories are as
follows. Working status (both not working, dual-working couples 5 , dual-wage earner, andpure dual-wage earner); number of coresiding children (0, 1, 2, 3, 4 and > 4); husband’s age(< 26, 26–35, 36–45, 46–55, 56–65, and > 65); quartiles of income (4th quartile is therichest)6; household size (< 4, 4, 5, and > 5); and dual-chore undertaken couples7. This is toseparate the influence of these categories on the variables of interest and to provide an insight
into any differences, if they exist. These categories help us to check the robustness of theresults relative to the reduced forms equations of (5).
In addition, we apply three measures to deal with the high correlations between gas
cookers and rice cookers8/washing machines 9 /freezers (0.52, 0.37, and 0.43, respectively).
First, we conduct principal component analysis by constructing the first principal component(𝑃𝐶𝐴) from six interaction terms between gender and home appliance variables. Second, we
retain gas cookers, vacuum cleaners, and microwave ovens in the analyses. Finally, we
estimate separately each of the variables of interest for each of the data samples. We test theirsigns and statistical significance across the various data samples. We report the analyses with
𝑃𝐶𝐴 and three appliances as the main results, and present the other results in the Appendix.

5

Dual-working couples are those who both do some work for income. Dual-wage earners are those that both dosome jobs for wages.
6This is because the rich have more tools (Cowan 1983).
7
Couples that spent at least one minute on unpaid housework.
8
Unfortunately, the GSO uses the same code for rice cookers, electronic cookers, and pressure cookers.
Therefore, we refer to this variable as “rice cookers” and use the coded variable to construct PCA for the six
variables.
9
The variable “washing machine” represents both washing machines and driers.

6

4 Results
As shown in Table 4, the gender gap of time spent on unpaid housework is persistent andapproximately 40.3 to 58.6 minutes per day. The gap is 18.24 minutes lower if both thehusband and wife do unpaid housework for at least a minute each day. When comparing the
gap across the data samples in Table 5, the gaps are statistically significant in 26 samples
regardless of the working status, number of coresiding children, birth cohorts, income levels,and household sizes. This is consistent with the results of Vu (2014) who finds a daily 5.25minute gender gap between Vietnamese siblings aged less than 18 years on daily unpaid
housework.
[Insert Tables 3, 4, and 5 here]
We find a substitution between paid work and unpaid housework in Table 3. The rateis different between men and women: 55 (43) minutes of paid work for one hour of unpaid
housework for women (men). However, without any paid work, as seen in column (4) of
Table 4, the gap is still 52 minutes each day.
Home appliances are associated with different amounts of time spent on housework
between husbands and wives. For example, in Table 3, gas cookers help to reduce the timespent on unpaid housework for the husbands by much as 1.8 minutes per day. However, gas
cookers increase the amount of unpaid housework of wives by 3.8 minutes per day.
The time gap between wives and husbands increases in association with theappearance of home appliances. As shown in column (1) of Table 4, the first principal
component of the six home appliances increases the gap by 4.7 minutes per day for wives. We
find the estimated 𝑃𝐶𝐴 is statistically insignificant among pure dual-wage earners, couples
with more than four children, husbands aged less than 26, and those in the lowest income
quartile as shown in Table 5.
Examining the effects of specific appliances, we find the interaction term constructedfrom gas cookers and gender has the most statistically significant coefficient of 16.9 minutes
per day as shown in column (2) of Table 4. The significance of the coefficients is independentof model specifications that include or exclude other home appliances as shown in thecorresponding coefficients in both Table 5 and the Appendix. However, the coefficients
become statistically insignificant for pure dual-wage earners where the husband is aged lessthan 26 years. Among the couples living with more than four children or in the lowest income

7quartile, the statistically insignificant 𝑃𝐶𝐴 could be due to the opposite signs of theinteraction terms.
The decision to participate in unpaid housework is one of the main reasons for women
spending more time on housework following the appearance of gas cookers. We find that witha gas cooker, husbands are 6% less likely to do unpaid housework, while the wife is only
0.6% less likely as shown in Table 6. This might be because men believe that the cooking
with a gas cooker is not difficult enough to warrant their help. Without a gas cooker, men may
become involved in tasks such as collecting and chopping firewood.
[Insert Table 6 here]
We hypothesize some additional reasons for the increased gender gap in timeassociated with the appearance of home appliances, particularly gas cookers. First, it could bethat men do less housework while women do more, as shown in columns (7) and (8) of Table
3. Second, although gas cookers reduce cooking time because of convenient heat adjustment
and multiple-task heating, they allow women to cook more dishes per meal. Thus, the total
time spent using gas cookers and cleaning dishes (we assume that women are more likely to
do such cleaning) increases. Third, gas cookers might be more closely related to wives’ tasks,
whereas other home appliances could be gender-neutral. Washing machines, microwave
ovens, and vacuum cleaners do not require a specific strength or skill related tofeminine/masculine characteristics. Fourth, wives could be more involved because they
consider cooking time as leisure time. Indirect evidence is that women who are pure dualwage earners are more likely to participate (a 1.25% increase) if the household owns a gas
cooker (see Table 6).
Meanwhile, among pure dual-wage earners, we would argue that the time adjustmentof the couples when all income comes from paid work would be rigid. Thus, time constraints
give women no opportunity to increase time spent on unpaid housework even if it isconsidered a leisure activity. Furthermore, by having stable income, women can have morebargaining power. Thus, men cannot avoid collaborating with women and sharing tasks
related to gas cookers. These arguments could explain why the time gap in the two groups isthe same, and why women are more likely to do housework where a gas cooker is available.

85 Conclusions and discussion
We examined the time spent on unpaid housework by 36,480 Vietnamese couples. The
gender gap is persistent across generations despite changes in the Vietnamese economy.
Despite differences in household composition in terms of age, size, income, number ofcoresiding children, and working status, we found that husbands spend 40.3–58.6 fewer
minutes each day on unpaid housework than their wives do. One of the important reasons isthat men are less likely to do housework. Working status can explain the substitution between
paid work and unpaid housework. However, among dual-nonworking couples, the gender gapof time was still 52 minutes. We also found that some home appliances (such as microwave
ovens and gas cookers) reduce the time spent on housework by husbands. Nevertheless, thegender gap of time increases with the appearance of home appliances such as gas cookers. We
found that a reduction in the probability of men participating in housework tasks related togas cookers is one of the main reasons for the larger gap. In addition, a woman may do morehousework as a leisure activity and because a gas cooker enables her to cook more dishes anddo other related tasks (such as cleaning). However, this effect does not exist among pure dualwage earners or in cases where husbands are aged less than 26 years.
We acknowledge several limitations of our data and analyses. First, the time spent onhousework is retrospective, but not in a form of time use survey where each specific task ofeach individual is recorded with both the starting and the ending time. Second, we bypassed
the self-selection of men and women toward specific tasks, the productivity of doinghousework and the collaboration between couples on the same task. Thus, the gender gap
might be associated with the specific tasks included in the survey. Third, we were only able toconsider gas cookers, but not other types of cookers such as electronic cookers, pressure
cookers, and rice cookers. This is because the survey coded the three mentioned cookers inthe same variable.
The positive relationship between gender gap of time and the appearance of home
appliances has several policy implications. First, the gap exists because individuals might beself-selected to certain specific tasks of unpaid housework. Thus, policies to increase theparticipation of women in paid work should consider this effect. Second, the positive
interaction terms indicate that the policies facilitating the participation of men in housework
also empower women. This can also influence the marketing strategies of the suppliers ofhome appliances. Similarly, policies aimed at empowering women via microcredit should9consider this interaction. Finally, our study confirms the existence of gender roles in terms of
unpaid housework between husbands and wives.

References
Beblo M, Robledo JR (2008) The wage gap and the leisure gap for double-earner couples. J
Popul Econ 21(2):281–304. doi:10.1007/s00148-006-0132-5
Bloemen HG, Pasqua S, Stancanelli EGF (2010) An empirical analysis of the time allocationof Italian couples: are they responsive? Rev Econ Househ 8(3):345–369.
doi:10.1007/s11150-009-9083-4
Connelly R, Kimmel J (2009) Spousal influences on parents’ non-market time choices. Rev
Econ Househ 7(4):361–394. doi:10.1007/s11150-009-9060-y
Cowan RS (1983) More work for mother. Basic Books, New York.
Folbre N, Nelson JA (2000) For love or money—or both? J Econ Perspect 14(4):123–140.
doi:10.1257/jep.14.4.123
Gershuny J, Sullivan O (2014) Household structure and housework: Assessing thecontributions of all household members, with a focus on children and youths. Rev Econ
Househ 12(1):7–27. doi:10.1007/s11150-013-9234-5
Gough M (2011) Unemployment in families: The case of housework. J Ind Econ 59(3):1085–
1100. doi:10.1111/j.1741-3737.2011.00867.x
Goux D, Maurin E, Petrongolo B (2014) Worktime regulations and spousal labor supply. Am
Econ Rev 104(5639):252–276. doi:10.1257/aer.104.1.252
Gronau R (1977) Leisure, home production, and work––the theory of the allocation of timerevisited. J Polit Econ 85(6):1099. doi:10.1086/260629
Hersch J (2009) Home production and wages: Evidence from the American Time Use Survey.
Rev Econ Househ 7(2):159–178. doi:10.1007/s11150-009-9051-z
Hersch J, Stratton LS (1994) Housework, wages, and the division of housework time for
employed spouses. Am Econ Rev 84(2):120–125.
Hersch J, Stratton LS (1997) Housework, fixed effects, and wages of married workers. J Hum
Resour 32(2):285–307.
Kroska A (2003) Investigating gender differences in the meaning of household chores andchild care. J Marriage Fam 65(2):456–473. doi:10.1111/j.1741-3737.2003.00456.x
Poortman AR, Van Der Lippe T (2009) Attitudes toward housework and child care and thegendered division of labor. J Marriage Fam 71(3):526–541. doi:10.1111/j.17413737.2009.00617.x
10Stratton LS (2012) The role of preferences and opportunity costs in determining the time
allocated to housework. Am Econ Rev 102(3):606–611. doi:10.1257/aer.102.3.606
Ueda A (2005) Intrafamily time allocation of housework: Evidence from Japan. J Jpn Int
Econ 19(1):1–23. doi:10.1016/j.jjie.2003.12.002
Vu TM (2014) Are daughters always the losers in the chore war? Evidence using household
data from Vietnam. J Dev Stud 50(4):520–529. doi:10.1080/00220388.2013.875535
Wales TJ, Woodland, AD (1977) Estimation of the allocation of time for work, leisure, andhousework. Econometrica 45(1):115–132.

11

Table 1 Descriptive statistics of husbands and wives in the selected sample
Variables
UHW (daily hours of unpaid housework)
PW (daily hours of paid work)
UHW (daily hours of unpaid housework > 0, N = 25,924)
PW (daily hours of paid work > 0, N = 30,253)
Work for income (1 = yes, 0 = no)Dual-wage earners
Pure dual-wage earners
AgeYears of schooling
Absence (Absent days from routine tasks in previous 12 months)
Ill days (Number of days in illness in previous 12 months)

Wife
Mean
2.354
3.815
2.380
4.364
0.874
0.646
0.102
45.553
6.953
5.673
1.741

Std. dev.
1.238
2.619
1.096
2.310
0.332
0.478
0.303
11.9164.081
19.41911.399

Min.
0
0
1
0.011
0
0
0
18
0
0
0

Max.
8
17.7538
16.767
1
1
1
92
20
365
365

Husband
Mean
1.149
4.013
1.560
4.428
0.901
0.498
0.159
48.459
7.986
5.680
2.229

Std. dev.
0.994
2.508
0.808
2.200
0.299
0.500
0.366
12.3594.046
22.37716.726

Min.
0
0
1
0.016
0
0
0
18
0
0
0

Max.
8
16.767
8
16.767
1
1
1
98
19
365
365

Total number of households = 36,480

12

Table 2 Descriptive statistics of households in the selected sample
Variables
0 childrena
1 child
2 children
3 children
4 children
More than 4 children
Number of children aged < 7
Number of children aged 7–12
Number of children aged 13–17
Number of other adults (age > 18 & excluding the head and thehead’s spouse)
House living area in square meters
Tap water (being used)
Freezer
Washing machine
Gas cooker
Rice cooker
Vacuum cleaner
Microwave oven
Urban
a

Mean
0.106
0.211
0.408
0.177
0.064
0.099
0.400
0.446
0.538

Std. dev.
0.307
0.408
0.491
0.382
0.244
0.299
0.662
0.675
0.719

Min.
0
0
0
0
0
0
0
0
0

Max.
1
1
1
1
1
1
8
5
5

3.041
69.470
0.215
0.311
0.119
0.446
0.693
0.012
0.024
0.245

1.190
40.386
0.411
0.463
0.323
0.497
0.461
0.109
0.152
0.430

2
5
0
0
0
0
0
0
0
0

10
1,056
1
1
1
1
1
1
1
1

Children are those of the head and are coresiding in the household. Total number of households = 36,480

13

Table 3 Seemingly unrelated regressions with four decisions on time spent on paid work andunpaid housework
Variables
PW–w

1st PC of 6 appliances
PW–w
PW–h
UHW–w
(1)
(2)
(3)
–0.263***0.601***(0.004)

PW–h
UHW–w
UHW–h
Absence–w
Ill day–w

0.681***(0.005)–0.913***(0.009)0.746***(0.012)–0.010***(0.001)–0.010***(0.001)

Absence–h0.636***(0.009)–0.721***(0.011)–0.010***(0.000)–0.008***(0.001)Ill day–h
Living without a childChilda aged < 7Child aged 7–12
Child aged 13–17
Number of adults
House living area
Tap water
PCA (6 appliances)(0.003)0.191***(0.003)0.347***(0.006)–0.005***(0.000)–0.007***(0.001)0.002***(0.000)0.003***(0.000)0.023(0.023)0.011(0.010)–0.029***(0.009)–0.070***(0.009)–0.056***(0.006)0.000***(0.000)0.041**(0.018)0.015***(0.005)UHW–h(4)0.144***(0.002)–0.158***(0.002)0.246***(0.004)0.003***(0.000)0.005***(0.000)–0.003***(0.000)–0.004***(0.000)0.088***(0.020)0.002(0.008)–0.019**(0.008)–0.074***(0.008)–0.073***(0.005)–0.000(0.000)–0.045***(0.015)–0.014***(0.004)Three appliances
PW–w
PW–h
(5)
(6)
0.601***(0.004)0.681***(0.005)–0.913***(0.009)0.746***(0.012)–0.010***(0.001)–0.010***(0.001)0.636***(0.009)–0.721***(0.011)–0.010***(0.000)–0.008***(0.001)

Gas cooker
Vacuum cleaner
Microwave oven
Age and age ^2
Schooling years
Provinces & urban
Constant

Yes
Yes

Yes
Yes

0.631***(0.144)

Observations
R–squared

36,480
0.182

Yes

Yes

1.403***(0.148)Yes
1.967***(0.090)36,4800.239

36,480
0.107

UHW–w
(7)

UHW–h
(8)

–0.263***(0.003)0.190***(0.003)0.144***(0.002)–0.158***(0.002)0.246***(0.004)0.347***(0.006)–0.005***(0.000)–0.007***(0.001)0.002***(0.000)0.003***(0.000)0.022(0.023)0.012(0.010)–0.028***(0.009)–0.069***(0.009)–0.056***(0.006)0.000***(0.000)0.042**(0.018)0.003***(0.000)0.005***(0.000)–0.003***(0.000)–0.004***(0.000)0.089***(0.020)0.001(0.008)–0.019**(0.008)–0.074***(0.008)–0.073***(0.005)–0.000*(0.000)–0.047***(0.015)0.063***(0.014)0.002(0.055)–0.006(0.041)
Yes–0.030**(0.012)–0.031(0.047)–0.067*(0.035)
Yes

Yes
Yes

Yes
Yes

Yes
0.632***(0.083)0.630***(0.144)1.405***(0.148)Yes
1.943***(0.090)Yes
0.656***(0.083)36,4800.040

36,4800.182

36,4800.239

36,4800.108

36,4800.040

Robust standard errors in parentheses (*** p < 0.01, ** p < 0.05, * p < 0.1). Children are those of the head andare coresiding in the household

14

Table 4 Household fixed-effect models on time spent on unpaid housework
1st PC from 6
appliances
Variables
Sex
PCA

UHW
(1)
0.952***(0.029)0.078***(0.007)

Gas cooker  sex
Microwave oven  sex
Vacuum cleaner  sex
Working hour
AbsenceIll day
Dual-wage earners
Pure dual-wage earners
Age and age ^2
Head of the household
Self-employed (types 1–3)
Working (dummy)
N/2–1 dummies of households
Constant
Observations (N)R–squared
Adjusted R–squared–0.116***(0.007)–0.006***(0.001)–0.008***(0.001)–0.345***(0.031)–0.380***(0.059)
Yes
Yes
Yes
Yes
Yes
2.001***(0.299)72,960
0.704
0.408

Three
appliances
All
UHW
(2)
0.976***(0.028)Both do chores
UHW(3)
0.672***(0.026)

Both do not work
UHW
(4)
0.863***(0.127)0.281***(0.025)0.274***(0.103)0.004(0.119)–0.115***(0.007)–0.006***(0.001)–0.008***(0.001)–0.344***(0.031)–0.382***(0.060)
Yes
Yes
Yes
Yes
Yes
1.954***(0.299)72,9600.704
0.408

0.197***(0.023)0.299***(0.106)0.114(0.121)–0.080***(0.006)–0.002***(0.001)–0.004**(0.002)–0.288***(0.029)–0.206***(0.061)
Yes
Yes
Yes
Yes
Yes
2.869***(0.317)
51,8480.738
0.469

0.439***(0.129)0.108(0.263)–0.492(0.375)–0.006***(0.001)–0.008***(0.001)

Yes
Yes

Yes
12.396***(3.771)
3,972
0.721
0.439

Robust standard errors in parentheses (*** p < 0.01, ** p < 0.05, * p < 0.1)

15

Table 5 Interaction terms by data sample
Data selections

N

1st PC from 6 appliances

Three appliances

Sex

St. err.

PCA

St. err.

Sex

St. err.

Gas cooker sex

St. err.

Microwave sex

St. err.

Vacuum sex

St. err.

All(1)

72,9600.952***(0.029)0.078***(0.007)

0.976***(0.028)0.281***(0.025)0.274***(0.103)0.004(0.119)Dual-nonworking

(2)

3,972

0.874***(0.136)0.101***(0.036)

0.863***(0.127)0.439***(0.129)0.108(0.263)–0.492(0.375)Dual-working(3)60,506

0.881***(0.030)0.062***(0.007)0.910***(0.029)0.204***(0.024)0.250**(0.120)0.172(0.127)Dual-wage earner(4)12,1201.001***(0.060)0.043***(0.016)1.013***(0.057)0.145***(0.054)0.010(0.234)0.347(0.241)

Pure dual-wage earner

(5)

4,642

1.149***(0.112)0.026(0.031)

1.179***(0.105)0.051(0.105)–0.150(0.251)0.498*(0.276)

Living without a child

(6)

7,708

0.803***(0.077)0.060***(0.021)0.848***(0.076)0.143*(0.074)

0.526*(0.302)–0.089(0.245)

1 childa(7)15,3660.978***(0.061)

0.066***(0.017)

0.992***(0.056)

0.236***(0.054)0.274(0.233)0.042(0.269)2 children(8)29,7340.918***(0.044)0.083***(0.011)0.939***(0.042)0.306***(0.037)0.195(0.143)0.086(0.178)3 children(9)12,9161.025***(0.088)0.096***(0.017)1.079***(0.090)0.324***(0.064)0.448*(0.240)–0.096(0.264)4 children

(10)

4,664

1.094***(0.129)0.066**(0.030)1.105***(0.123)0.251**(0.102)0.501(0.607)–0.366(0.679)> 4 children

(11)

2,572

1.210***(0.167)0.033(0.039)1.140***(0.162)0.363**(0.163)–1.069(0.680)–0.229(1.230)Husband aged < 26

(12)

576

1.033***(0.368)0.081(0.065)1.120***(0.377)0.143(0.365)

Husband aged 26–35

(13)

9,308

0.949***(0.087)0.040**(0.018)0.910***(0.084)0.273***(0.069)–0.266(0.341)

0.191(0.362)

Husband aged 36–45(14)

23,2920.990***(0.054)0.062***(0.013)1.010***(0.053)

0.236***(0.042)0.109(0.263)0.126(0.249)Husband aged 46–55(15)

21,686

0.952***(0.049)0.090***(0.012)

0.994***(0.047)0.287***(0.044)0.291**(0.144)0.156(0.170)Husband aged 56–65(16)

10,1920.853***(0.077)0.105***(0.020)0.918***(0.071)0.314***(0.066)0.410*(0.238)–0.350(0.283)

Husband aged > 65

(17)

7,906

0.799***(0.095)0.072***(0.022)0.805***(0.093)0.272***(0.082)0.437*(0.254)–0.017(0.408)

1st quartile income(18)

18,2360.855***(0.064)0.017(0.014)0.849***(0.063)0.194***(0.073)–0.855(1.149)0.237(0.436)

2 quartile income(19)

18,2380.967***(0.055)0.033**(0.014)0.949***(0.052)0.224***(0.047)0.118(0.425)–0.266(0.378)

3rd quartile income(20)

18,252

1.056***(0.062)0.055***(0.016)1.081***(0.057)0.169***(0.048)0.511*(0.265)–0.096(0.307)

4 quartile income(21)

18,2340.970***(0.071)

0.096***(0.019)1.041***(0.069)0.249***(0.065)

0.198*(0.115)–0.010(0.141)

Household size < 4(22)18,4080.917***(0.054)0.054***(0.015)0.927***(0.050)0.197***(0.049)0.224(0.222)–0.030(0.228)Household size = 4(23)24,9900.930***(0.048)0.086***(0.011)

0.971***(0.046)

0.267***(0.041)0.351**(0.150)0.165(0.196)

Household size = 5(24)

15,1380.969***(0.069)0.090***(0.015)1.004***(0.071)0.333***(0.055)0.328(0.241)–0.048(0.257)

Household size > 5(25)

14,424

1.048***(0.078)0.072***(0.016)

1.047***(0.074)0.343***(0.060)0.161(0.244)–0.209(0.303)

Dual chore undertaken(26)

51,8480.630***(0.027)0.067***(0.007)0.672***(0.026)

0.197***(0.023)0.299***(0.106)0.114(0.121)ndthChildren are those of the head and coresiding in the household

16

Table 6 Mean comparison tests between two samples, with and without gas cooker
Data selections

Gas cooker available (A)Without gas cooker (B)Difference

Obs.

Mean

Obs.

Mean

(A)–(B)

Participation–Ha

16,2790.695820,2010.7563–0.0605***

Participation–WAll
16,2790.959920,2010.9659–0.0060***b

16,2791.3831

20,201

1.06220.3209***Time gap–b

10,9840.9306

14,9400.73820.1924***

Participation–H

1,753

0.7467568

0.69190.0548

Participation–W

1,753

0.9738568

0.96130.0125**Time gap–a

1,753

1.2801568

1.23240.0477

Time gap–b

1,286

0.9393384

0.86460.0747

Participation–H

62

0.8065226

0.8717–0.0652

Participation–W

62

0.9839226

0.99560.0117

Time gap–a62

1.4839226

0.95580.5281***Time gap–b

50

1.100

196

0.69900.4010**Time gap–aPure dual-wage owners

Age husband < 26*** p < 0.01, ** p < 0.05, * p < 0.1.
aParticipation–H (W) is percentage of husbands (wives) who spent at least one minute on unpaid houseworkbTime gap–a (b) is the time difference between a wife and husband using the sample of all (dual chore

undertaken) couples

17

Appendix Robustness checks by separating each home appliance per estimation and by data sample
Data selections

N

Interaction between sex andMicrowave
Gas cooker Std. err.
ovenStd. err.

VacuumcleanerStd. err.

FreezerStd. err.

Washing
machineStd. err.

Rice
cooker

Std. err.

All

(1)

72,9600.295***(0.025)0.399***(0.097)0.224**(0.113)0.244***(0.028)0.326***(0.044)0.138***(0.025)Dual-nonworking

(2)

3,972

0.434***(0.127)0.142(0.249)–0.348(0.353)0.358***(0.127)0.328**(0.152)0.289*(0.151)

Dual-working(3)60,5060.218***(0.024)0.383***(0.113)0.349***(0.121)0.181***(0.027)

0.291***(0.046)0.107***(0.024)Dual-wage earner(4)12,1200.158***(0.054)0.169(0.205)0.408**(0.201)0.149**(0.062)0.161*(0.084)0.063(0.056)

Pure dual-wage earner

(5)

4,642

0.058

(0.104)0.001(0.222)0.421*(0.230)0.091(0.099)0.024(0.106)0.051(0.123)

Living without a child

(6)

7,708

0.165**(0.073)0.579**(0.286)0.125(0.240)0.203**(0.084)0.357**(0.175)–0.003(0.077)

1 childa(7)15,3660.254***(0.054)0.383*(0.219)0.242(0.259)0.197***(0.060)0.263***(0.094)0.094*(0.056)

2 children(8)29,7340.318***(0.037)

0.335**(0.135)0.273(0.170)0.237***(0.040)0.306***(0.057)0.158***(0.039)3 children(9)12,916

0.341***(0.064)0.567**(0.223)0.213(0.234)0.358***(0.072)0.431***(0.121)0.173***(0.061)

4 children

(10)

4,664

0.264**(0.103)0.539(0.545)0.039(0.541)0.100(0.130)0.442*(0.245)0.192**(0.093)More than 4 children

(11)

2,572

0.326**(0.162)–0.933(0.580)–1.073(1.107)0.221(0.188)–0.027(0.362)0.376***(0.133)

Husband age < 26

(12)

576

0.143

(0.365)0.474(0.441)

0.482(0.833)0.411(0.260)Husband age 26–35

(13)

9,308

0.268***(0.068)–0.065(0.356)0.220(0.369)0.155*(0.083)0.044(0.126)

0.153**(0.065)

Husband age 36–45(14)

23,2920.243***(0.042)0.241(0.233)0.256(0.212)0.199***(0.048)0.227***(0.078)0.156***(0.042)

Husband age 46–55(15)

21,6860.308***(0.044)0.445***(0.135)0.377**(0.160)0.237***(0.047)0.385***(0.073)0.135***(0.047)

Husband age 56–65(16)

10,1920.333***(0.065)0.477**(0.228)–0.075(0.267)0.349***(0.073)0.544***(0.108)0.116*(0.070)Husband age > 65

(17)

7,906

0.302***(0.081)0.556**(0.250)0.274(0.410)0.252***(0.091)0.252*(0.146)0.056(0.083)

1st quartile income(18)

18,2360.190***(0.073)–0.711(1.147)0.217(0.400)0.023(0.112)–0.166(0.278)0.051(0.043)

2 quartile income(19)

18,2380.224***(0.047)0.182(0.418)–0.227(0.389)0.008(0.062)0.061(0.190)0.024(0.045)

3rd quartile income(20)

18,2520.174***(0.048)0.556**(0.270)0.008(0.300)0.091*(0.051)0.203**(0.089)0.040(0.061)

4 quartile income(21)

18,2340.267***(0.064)0.233**(0.107)0.112(0.132)0.269***(0.055)0.224***(0.058)0.050(0.084)

Household size <4(22)18,4080.208***(0.049)0.304(0.209)0.124(0.216)0.183***(0.056)0.240**(0.096)0.033(0.050)Household size = 4(23)24,9900.288***(0.040)0.494***(0.141)

0.393**(0.188)0.242***(0.044)0.323***(0.063)0.154***(0.044)

Household size = 5(24)

15,1380.345***(0.054)0.457**(0.228)0.206(0.246)

0.291***(0.060)0.391***(0.099)0.167***(0.052)

Household size > 5(25)

14,4240.347***(0.060)0.272(0.224)0.034(0.275)0.251***(0.068)0.340***(0.112)0.205***(0.056)

Dual chore undertaken(26)

51,8480.214***(0.023)0.413***(0.100)0.306***(0.116)0.205***(0.027)0.299***(0.044)0.142***(0.022)ndthaChildren are those of the head and are coresiding in the household18