Panel Data Research Center at Keio University
DISCUSSION PAPER SERIES
DP2014-005
March, 2015

Time-adjusted poverty among working households in Japan:
Two-dimensional poverty line approach

Kayoko ISHII＊
Kunio URAKAWA＊＊【Abstract】

Time is a finite resource along with money, and it is essential to fulfilling the basic
needs of life. This research focuses on ‘time poor’ individuals in Japan, where people do
not have enough time to engage in child care and housework as well as leisure and otheractivities. We defined income and time poverty thresholds and estimated thetime-adjusted income poverty by considering the situation where households fall into
income poverty by purchasing housework-related services in the market to compensate
for their time deficit. Based on the estimated results, we demonstrated that the
government needs to increase the policy support, especially for single-parents withchildren and for double-income couples with children.
＊

Graduate School of Business and Commerce, Keio University＊＊

Faculty of Economics, Kyushu University

Panel Data Research Center at Keio University
Keio University

Time-adjusted poverty among working households in Japan:
Two-dimensional poverty line approach
Kayoko ISHII (Keio University)
Kunio URAKAWA (Kyushu University)

Abstract

Time is a finite resource along with money, and it is essential to fulfilling the basic needs of life.
This research focuses on ‘time poor’ individuals in Japan, where people do not have enough time toengage in child care and housework as well as leisure and other activities. We defined income and timepoverty thresholds and estimated the time-adjusted income poverty by considering the situation where
households fall into income poverty by purchasing housework-related services in the market tocompensate for their time deficit. Based on the estimated results, we demonstrated that the government
needs to increase the policy support, especially for single-parents with children and for double-income
couples with children.

1． Introduction
Since the late 1990s, much research in Japan has shown the existence of enlarging disparity andpoverty. Most of these researches estimate the degrees of disparity and poverty by using monetary
indicators such as income and assets (Tachibanaki 2005; Ohtake 2005; Oshio and Urakawa 2008). Indeed,
when we evaluate the level of people’s standard of living, the monetary criterion is one of the mostwell-defined and tractable indicators because we can obtain most essentials with money.1
In addition, time is also an important factor determining the level of standard of living. Time is a finite
resource along with money in life, and we definitely need to obtain a certain amount to keep a certain
degree of living standards. Therefore, it’s important to focus on the dimensions of time as well as money.
In recent years, the lifestyles have become more diversified, so the time for daily family life such as
housework, child-rearing, and shopping are very different by household type. In a household such as
double-income family who lacks the necessary time for family life, the additional costs for purchasing
homemaker services will occur, and that will change the income level necessary for meeting the basic
needs. Taking account of the time deficit, we will be able to more clearly grasp the current status ofpoverty in Japan.
1

According to the data from the National livelihood survey in 2010 by the Ministry of Health, Labor and Welfare,the relative poverty rate by equivalent disposable income in 2009 is 16.0 percent and it marks higher than the OECDaverage of 10.6% in mid-2000s.

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As far as we know, the estimation of poverty focusing on people’s living hours has not been conductedin Japan. Therefore, in this paper we estimate ‘time poverty’ , which we define as the percentage ofhouseholds whose minimum times for the housework are lacking by household types, using thehousehold micro data sets in Japan.
By grasping poverty from two dimensions of income and time, we can clarify that: (1) what kind ofhouseholds are likely to fall into income and time poverty, (2) how are income poverty and time poverty
related. (Is it really for “No rest for the wicked” ?), and, (3) how many households eventually fall into
time-adjusted income poverty, based on the situation that they need to buy the minimum required level ofthe housework through the market.

2. Preceding studies
Vickery (1977), the pioneer research in time poverty, added the concept of time to the conventional
measure of poverty based on money. Based on the intra-household distribution model of Becker (1965),
Vickery (1977) defined that household resources consisted of “assets,” “time,” and “abilities of household
members.” The model of Becker (1965) determines the optimal level of housework and balance between
saving and consumption by appropriately distributing the time of each household to market labor andhousehold labor based on the household member abilities. Considering this theory, Vickery (1977)
presented a two-dimensional poverty line using data of the United States. More specifically, the study
estimated the minimum income required (M0), the minimum time required for household work (T1), andthe minimum income required when outsourcing the household work (M1) for each household type. The
study also calculated the poverty rate for households of each type and critical wage rate to be free frompoverty.
There are some studies which have been made by following the concept of the two-dimensional
poverty line of Vickery (1977). Douthitt (2000), for instance, used the 1985 American Time Use Survey
and attempted to updates the research of Vickery (1977). Harvey and Mukhopadhyay (2007) measured
the two-dimensional poverty rates in the late 1990s of Canada and revealed high time-poverty rates ofsingle-parent households (with two or more children). The study subsequently estimated an approximate
2% rise in income-poverty rate by taking into account the cost of outsourcing housework and childcare
paid by ‘time-poor’ households. Similarly, Kalenkoski et al. (2011) verified variables correlated to timepoverty using data from the American Time Use Survey Data and indicated that income poverty had no
statistical correlation with time poverty. The study also discovered an increase of one child would reduce
approximately 35 min per day of the daily discretionary time (time available for sleeping, getting dressed,
doing housework and taking care of children in general, and activities other than labor) of adults. In
addition, Burcahrdt (2010) used the UK Time Use Survey 2000 to investigate the relations between timepoverty and personal attributes such as education, income, and race.
Other studies have analyzed poverty by focusing only on the aspect of time (Goodin et al. 2005;

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McGinnity and Russell 2007; Goodin et al. 2008). Goddin et al. (2008) argued in detail about thedefinition of time poverty and examined how the welfare policies can be expected to affect the amount of
discretionary time of individuals. McGinnity and Russell (2007) and Goodin et al. (2008) analyzed thegender inequalities in time use among households..
Although two-dimensional poverty based on time and money has yet to be studied in Japan to the best
knowledge of the authors, some researchers have analyzed living hours. They primarily emphasized thework-life balance of households with small children. Many of them implied the burden of time constraints
suffered, in particular, by working single parents with children (Tamiya and Shikata 2007; Japan Institutefor Labour Policy and Training 2012; Cabinet Office 2013, etc.). For example, Tamiya and Shikata (2007)
focused on single-mother households, analyzed the management of work and childcare in terms ofinternational comparison, and pointed out that single mothers in Japan worked significantly longer hours
and spent shorter time taking care of their children than those in the United States and Europe. The Japan
Institute for Labour Policy and Training (2012) conducted the Survey on Living Conditions ofHouseholds with Children and the Work Arrangement of Parents and developed various statistics basedon the results. While only 7.6% of working mothers of two-parent households had answered they haveconflict between work and family life “almost every day”, 16.8% of working single mothers and 13.8% of
working single fathers had answered so. This also indicates the heavy burden of time constraints on
single-parent households. These results suggest that poverty in life, particularly of households with smallchildren, can be understood more accurately by adding time constraints to monetary conditions in themeasure of poverty.

3. Analytical framework: two-dimensional poverty line based on income and time
Figure 1 presents a two-dimensional poverty line based on income and time. The vertical axis
represents income and the horizontal axis time, and M0 is the income-poverty line representing theminimum income required. T1 is the time-poverty line representing the minimum time needed forhousehold work. Tm is the largest value on the horizontal axis and expresses disposable time, which, more
specifically, is the value after subtracting time spent for basic activities (sleeping, eating, taking personalcare (excretion, bathing, getting dressed, etc.)) from the 24 hours of the day. The value left after
subtracting T1 from Tm is Ta. If the actual working hours Tw (including commuting time) exceed Ta near
the origin and encroaches the time-poverty line T1, then the household is regarded as ‘time poor’. We
assume that the values of all parameters, M0, Tm, T1, and Ta vary depending on the household type. Basedon the two axes, M0 and T1, the diagram can be divided into the upper right area for “not poor,” the lower
right area for “income poor but not time poor," the upper left area for “not income poor but time poor,”and the lower left area for “income poor and time poor."
Additionally, the area of “not income poor but time poor” can be divided into two types by assuming
substitution of time with money such as the purchase of housework services (dining out, using childcare

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services, etc.). When drawing a curve with the slope of the cost of housework services from point E, atwhich the income-poverty line and time-poverty line intersect, the intersection M1 with the vertical axis is
the minimum income required for outsourcing all necessary household labor. Households can be
categorized into the range above the curve, in which households would not be income poor even if theypurchased housework services to cover their time poverty (“not income poor after time adjustment”), andthe range below the curve, in which households would be income poor if they purchased houseworkservices (“income poor after time adjustment”).

(i). Setting an income-poverty line
This study defines an income-poverty line based on the standard of welfare benefits as Japan’s public
assistance system. The standard of welfare benefits on which the income-poverty line in this study relies
has materialized “the minimum standards of wholesome and cultured living” guaranteed by Article 25 of
the Constitution of Japan. Currently, the benefit standard is made consistent with the general consumption
level of the people through the “balanced standard method.” In this sense, the standard of public
assistance supposedly defines poverty from a relative perspective. Besides, it can also be considered anabsolute standard that is necessary for achieving “the minimum standards of wholesome and cultured
living.”
The minimum living expenses are calculated for the welfare standards by adding the following [B]through [F] for applicable households to the livelihood assistance standards [A], which are basic
operating expenses defined by the ages and number of household members. Considering the differencesin lifestyles and commodity prices in different regions, the welfare standard system divides the entire
nation into six categories (Region 1-1, Region 1-2, Region 2-1, Region 2-2, Region 3-1, and Region 3-2)
and determines the standard values.

[Minimum living expenses under the public assistance system][A] Livelihood assistance standards, which are basic operating expenses defined by the ages andnumber of household members[B] Additional assistance provided to specific households (disabilities, single mothers, childcare
allowance, expectant and nursing mothers, etc.)[C] Housing assistance provided to households living in rental homes[D] Educational assistance and allowance for high school, etc. learning material expenses provided
to households raising children[E] Long-term care standards for households incurring long-term care expenses[F] Medical assistance standards for households incurring expenses such as medical fees

This study regards those households whose after-tax incomes are lower than the minimum living

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expenses as being “income poor.” More specifically, the minimum living expenses were calculated foreach household by incorporating [A] livelihood assistance standards, [B] additional assistance for single
mothers and childcare, [C] housing assistance standards, and [D] educational assistance and allowance forhigh school, etc. learning material expenses. Vickery (1977) and other preceding studies calculated
income poverty in units of households, so comparison with the preceding studies becomes easy.
For [A] livelihood assistance standards, livelihood assistance standards (Type 1) and livelihood
assistance standards (Type 2) were calculated for each regional category, age of household members, andthe number of household members and standard calculations were performed. For [B] additional
assistance for single mothers, the additional amounts of assistance provided to single-mother households
were calculated for each regional category and the number of children. For [B] addition for childcare, theadditional amounts were calculated according to the ages and numbers of children (children’s numbers intheir siblings). For [C] housing assistance standards applicable only to families living in rental homes, thestandard amounts and special amounts specified for each regional category. For [D] educational
assistance standards and allowance for high school, etc. learning material expenses, the regular amounts
were calculated as specified for each type of schools attended by children. The long-term care assistance[E] and medical assistance [F] were excluded from the calculation of minimum living expenses becauseof the limitation of data. Table 1 presents the average amounts of minimum living expenses estimated foreach household type.

(ii). Setting a time-poverty line
Definitions of time vary among studies (Burchardt 2010, Kalenkoski 2011). Vickery (1977), Harvey
and Mukhopadhyay (2007) and other studies define a time-poverty line (T1 in Figure 1) as the minimum
time required for housework. A household incapable of securing the minimum time required forhousework because of long working hours in the market is considered ‘time poor’. The minimum timerequired for housework in this case means the least time needed for housework without outsourcing theseries of household chores. Vickery (1977) used a living hour survey of the time and defined theminimum time required for housework as the average time spent for housework at households with atleast one full-time homemaker.
Harvey and Mukhopadhyay (2007) followed Vickery (1977) and calculated similar values from the
Canadian General Social Survey. The studies used the average values of adults’ living hours for basic
activities (sleeping, eating, personal care (excretion, bathing, getting dressed, etc.)). More specifically,
Vickery (1977) used 10.2 hours per day as the average time spent by adults for basic activities, based on
the 1966 Michigan Time-use Survey of the United States. Harvey and Mukhopadhyay (2007) used 10.5
hours per day as the average time spent by adults for basic activities calculated from similar survey dataof Canada. In addition, both studies considered the minimum leisure time required, and Vickery (1977)
concluded such time to be 10 hours per week and Harvey and Mukhopadhyay (2007) 14 hours per week.

5Burcahrdt (2010) also defined time poverty from an absolute perspective. This study determined theminimum time required for basic activities referring to the preceding studies, minimum time for childcare
using the childcare guidelines of the United Kingdom, and minimum time for housework by applying the
average time spent for housework by households that did not outsource their housework at all.
This study defines a time-poverty line using these studies as a reference. The specific procedure is todetermine the time spent for basic activities (sleeping, eating, taking personal care (excretion, bathing,getting dressed, etc.)) and minimum time required for housework (T1) using the 2011 Survey on Time Useand Leisure Activities of the Ministry of Internal Affairs and Communications (MIC) as a reference. The
Survey on Time Use and Leisure Activities was conducted by the MIC once every five years to observe
the distribution of living hours and major leisure time activities of the Japanese people. The 2011 survey
included the participation by approximately 200,000 members of approximately 83,000 households who
were aged 10 and above.
As the time spent for basic activities, the study used the average time spent in the entire week by men
and women, separately, who were aged 20--64 years. The time for basic activities included 7.5 hours per
day for men and 7.2 hours per day for women for sleeping, 1.1 hours per day for men and 1.5 hours per
day for women for taking personal care, and 1.5 hours per day for men and 1.6 hours per day for womenfor eating. Following the example of the preceding studies, this study further included the minimum
leisure time required in the basic activity time. This was assumed to be one hour per day from Monday
through Friday and three hours per day on Saturdays and Sundays.
Because the minimum time required for housework (T1) means the least time needed for housework
without outsourcing the housework such as dining out, ordering food delivery, purchasing prepared food,and using housework-related services in the market economy, the study applied, for each household type
to be analyzed, the average time spent for housework at households with at least one adult who did notwork outside the home. More specifically, as a reference, the study used the time spent for housework athouseholds with a husband working outside and wife not working outside for households comprising amarried couple and children and households only of a married couple.
For one-person households and single-parent households, the study applied the housework time ofhouseholds without a member working outside the home. The housework activities include housework,
nursing care, childcare, and shopping based on the Survey on Time Use and Leisure Activities. The
average time spent for housework by men of one-person households is significantly shorter than that inother households. Because many men living alone are likely to outsource much of their housework by, forinstance, dining outside instead of cooking at home, the minimum housework time required for female
one-person households was substituted for male one-person households.
Table 2 presents the time spent for basic activities and minimum time required for housework (T1) ineach household type. As described later, the types of households to be analyzed are consistent with thosein the 2011 Survey on Time Use and Leisure Activities. In addition to the living hours of each household

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type used in this study, the living hours used by the preceding studies (Vickery (1977) and Harvey at al.
(2006)) are presented for a comparison. The basic activity time and minimum time required forhousework assumed in this study are smaller than the values in the preceding studies, and thetime-poverty line becomes lower for the difference. The likely reason is that, as revealed also by theinternational comparison made by the OECD (2011), the time spent by Japanese for leisure and personalcare is shorter than that in other countries, and note should be taken to the fact that this time-poverty linereflects the conditions and customs of the Japanese people.

(iii). Setting a substitution rate for household labor
As described earlier, this study assumes the substitution of time with money such as the purchase ofhousework services (dining out, using childcare services, etc.) and confirms the approximate number ofhouseholds that fall into income poverty because of such substitution. The price of housework services
must be specified in this analysis, and the preceding studies set such a price using their original methods.
Vickery (1977) assumed the substitution rate of household labor at 2.00 dollars to 2.50 dollars, stating thatthese prices were appropriate in comparison to the hourly wages of dishwashers and janitors of the time.
The study, then, examined cases with a constant and incremental substitution rate (starting with low-pricesubstitution such as dining out, then using high-price substitution such as childcare services later). Harvey
at al. (2006) applied the minimum wage of the time (6.55 Canadian dollars in 1998) as the substitution
rate for the calculation. Substitution rates for household labor might be determined in various ways, but
this study applies the price per hour for each household service in the actual market. The specifichousehold chores at T1 include three (shopping, housework, and childcare) and inflection points wereplaced by following the actual time allocation to each of the household chores2.
More specifically, home-delivery service for food and daily necessaries was assumed as thesubstitution for shopping, and the substitution rate was set at 833 yen per hour using the prices of chilled
home-delivery service of a large shipping company as a reference3. For housework substitution (cleaning,
washing, etc.), the study applied the price 3,240 yen (tax included) per hour for housekeeping services ofa large housekeeping service company as the substitution rate. For childcare substitution in householdswith children aged 10 or younger, the hourly childcare service fee calculated from the monthly fees
charged by certified day care centers in prefectural capitals presented in the 2011 Retail Price Survey ofthe MIC was applied to each child attending a preschool, and the hourly fee 4,464 yen (tax included)
charged by a large childcare company was applied to each child other than those attending a preschool.

2

In one-person households and couples without child household, childcare is not included in their household chores,
because it is not necessary. Also in households with the youngest children aged 10 years old and over, childcare is notincluded in their household chores.
3 We assume that they use chilled home-delivery service of a large shipping company 3 times a week, and it costs
2,916 yen per week (972 yen * 3). Suppose this service substitute for 30-minutes daily shopping, the hourly
substitution rate is going to be 833 yen (972 yen / 0.5 hours * 7 days).

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4. Data
Dataset used in this study is Japan Household Panel Survey (JHPS) conducted by Panel Data ResearchCenter at Keio University. JHPS is the panel data intended for about 4,000 adult persons from 2009 andincludes various fields of questions such as household attributes, employment status, income, life hours
and residential status. In this paper, we used pooled samples from year 2011 (JHPS2011) to year 2013
(JHPS2013) including a question about commute time for the analysis.
In addition, we restricted the target sample to households which offer the information on living hours(mainly labor hours) of adult persons. In the JHPS, it only asks for respondents and their spouses aboutliving hours, so in the case of a household which has another adult person, we cannot exactly grasp theinformation on those persons. Therefore, we excluded elderly households and mainly focused on thefollowing categories in this analysis.
One-person household (male)One-person household (female)Single-parent with children

Couple with one child younger than 6Couple with two or more children younger than 6Couple with children who are all older than 6Couple without child

As a result, we use the samples of 2,544 households. The breakout of the data is as follows: One-personhousehold (male) [n=221], One-person household (female) [n=141], Single-parent with children [n=73],
Couple with one child younger than 6 [n=421], Couple with two or more children younger than 6 [n=185],
Couple with children who are all older than 6 [n=893] and Couple without child [n=610]

5. Analytical results
A. Time poverty
First, the total working hours of a married couple (or the householder in the case of one-person andsingle-parent households), which constitute an important decisive factors of time poverty are confirmed in
Figure 2. The working hours for one-person and single-parent households are fewer than 40 hours per
week. A comparison only of cases in married-couple households work reveals that the working hours ofhouseholds of double-income couples without children are the longest, followed by households consistingof double-income parents and one preschooler (younger than six years old). The total working hours ofhouseholds having two or more preschoolers are the shortest. In other words, they may be adjusting theirworking hours according to their burden of childcare.

8This kind of burden of housework might affect the combinations of how married couples work (Figure3). Among the households with one preschooler, more than half of them are single earners, and 20% ofthem are double earners where husbands are full time workers and wives are part time workers. Amongthe households with more than two preschoolers, the share of this type of double earners is decreased, andthe share of single earners is increased by 70%. On the other hand, among the households with theyoungest child aged 6 years old and over, the share of single earners is decreased by 26%, and the shareof double earners is increased significantly.
Subsequently, the level of time poverty by household type can be examined. Table 3 shows leisure timeafter subtracting the total working and commuting time (Tw) from allocatable time (Ta) and estimates thedegree of time poverty of each household. Because the allocatable time (Ta) does not include theminimum time required for housework, a negative amount of leisure time suggests an inability tomaintain the minimum required housework time, which is therefore considered a state of being ‘time
poor’. Households with little leisure time are typically single-parent households. The average leisure timeof all single-parent households is 6.3 hours per week. Among married-couple households, those in which
both adults work outside the home apparently have less leisure time. The average leisure time ofhouseholds with preschoolers (younger than six years old) is known to be particularly little. The
percentage of households with a negative amount of leisure time, i.e., being ‘time poor’, by household
type is the highest for single-parent households at 40%, followed by households consisting of two
working parents and preschoolers(s) at 28%. Surprisingly, the time-poverty rate exceeds 10% even among
one-person households. The time-poverty rate is less than 10% among the households with two parents
and the youngest child aged six or older and households only of a married couple.
Except for one-person households, childcare is important factor underlying time poverty. What effect,then, does time poverty have on relationships with children in child-rearing households? Figure 4 presents
the degree of difference in the frequency of having dinner with child(ren) in a week between ‘time-poor’households and time-rich households. While 70% of parents in the time-rich households answered thatthey had dinner with their children every day or five to six days a week, less than 50% of those in the‘time-poor’ households had dinner with their children almost every day; about 30% of them answeredthat they accompanied their children only once or twice a week. Although this is only an example, it
demonstrates that time spent with children is reduced by long working hours and burdens of housework.

B. Two-dimensional poverty based on income and time
We estimated the poverty rate for each household type using a two-dimensional poverty line based on
income and time exhibited in Figure 1. First, the income-poverty rate, time-poverty rate, and concurrent
poverty rate (percentage of being both income and time poor) are examined for each household type(Table 4). Income poverty rates are measured somewhat higher, particularly for child-rearing households.
One reason for this is that the calculation of the income-poverty line using assistance standards takes into9

account childcare and education assistance in addition to housing assistance benefits. As found in thepreceding studies, the data reveal that both income-poverty and time-poverty rates become higher insingle-parent households and that even the concurrent poverty rate tends to be very high, at nearly 30%.
The income-poverty and time-poverty rates in one-person households are also somewhat high at 10% to20%. The concurrent poverty rate, however, is low, implying that income and time are in a trade-off
relationship in one-person households. Among the two-parent households, those with both parents
working full-time indicate low income-poverty but a high time-poverty rate.
Among the households that include preschooler(s) (younger than six years old), the concurrent poverty
rate of households with two working parents is somewhat high. Both the income-poverty andtime-poverty rates are low in households of a married couple without children, suggesting their affluence.
Subsequently, the percentages of the five poverty types presented in Figure 1 (“not poor,” “income
poor but not time poor,” “both income and time poor,” “income poor after time adjustment,” “not income
poor but time poor”) were calculated for each household type (Table 5). As noted earlier, the percentage
of “not income poor after time adjustment” was calculated on the assumption of substitution of household
labor with housework services, including shopping, housework, and childcare, purchased in the market.
The data show that 30.3% of the ‘time poor’ households (2.4% of total households) would fall into
income poverty and become “income poor after time adjustment” after increasing their allocatable timeby purchasing housework services in the market. In particular, the percentages of one-person households
and two-parent households having preschooler(s) are high at 5.2% and 4.1%, respectively. In other words,
although the poverty line that measured only income revealed merely “income-poor and time-poor” and“income poor but not time poor” households as having problems, considering poverty by adding theperspective of time unearthed the need to include the “income poor after time adjustment” households
into the poor in terms of income.

C. Multivariate regression analysis
This section presents examination of the relationships of factors such as time poverty, income poverty,
and one-sided poverty (either time or income poor) with each variable using a logistic model. Out of the2,544 households that have been analyzed thus far, the study analyzes 2,462 households having all
variables used for multivariate analysis, of which 2,032 are married-couple households (households
consisting of two parents and child(ren) and married-couple households without children). The
descriptive statistics are presented in Table 6.
Table 7 exhibits the results estimated for all households by the model using time poverty, income
poverty, and one-sided poverty as the explained variables. Table 8 displays the results estimated for only
married-couple households (households consisting of two parents and child(ren)” and “married-couple
households without children”) by the model using time poverty, income poverty, and one-sided poverty(either income or time poor) as the explained variables. The model using time poverty (1 if time poor,

10otherwise 0) as the explained variable was added with income-poverty dummy (1 if income poor,otherwise 0) that would measure the relationship between income poverty and time poverty as a common
variable, the householders’ educational background categories (high-school graduate, and two-yearcollege or technical college graduate, with university or graduate school graduate as the reference) as
variables expressing the householders’ productivity, the householders’ age categories (every ten years
from 20 years old with 60s as the reference), the regional categories of welfare benefits (six categories
from Region 1-1 to Region 3-2 with Region 1-1 as the reference ) as a variable to control theenvironmental factors of housing areas, and the survey year categories.
In addition, the analysis of all households used household type categories (one-person households,
single-parent households, households with two parents and the youngest child aged six or older, andhouseholds with two parents and the youngest child aged less than six years, with married two-personhouseholds without child as the reference).
The analysis only of married-couple households used the categories of married couples’ forms of work
(full-time employed couple, full-time employed husband and part-time employed wife, self-employedcouple, full-time employed husband and self-employed wife, other types of two-income households,
one-income households, and jobless households, with one-income households as the reference), andnumber-of-children categories (zero, one, and two or more, with zero as the reference). The model ofincome poverty (1 if income poor, otherwise 0) used the same explanatory variables, except for the inputof time-poverty dummy instead of the income-poverty dummy. The one-sided poverty (1 if either income
poor or time poor, otherwise 0) model used the same explanatory variables except the income-poverty
dummy and time-poverty dummy.
The relation between the household type with time poverty in Table 7 indicates a markedly highpossibility of falling into time poverty for one-person households, single-parent households, andhouseholds with two parents and child(ren) younger than six years old, in contrast to the case of married
two-person households. The potential of becoming ‘time poor’ is shown to be particularly high forsingle-parent households. The odds of single-parent households are substantially high in the relationshipbetween household types and income poverty. The possibility of income poverty is evidently the lowest
for the married two-person households used as the reference.
The effect of the form of employment of married couples in Table 8 suggests a significantly high odds
ratio of time poverty for two-income households, in contrast to one-income households, and thepossibility of falling into time poverty is particularly high for full-time employed couples andself-employed couples. As for the relationships with income poverty, the possibility of becoming income
poor is the lowest for households with full-time employed couples.
As for the effect of the number of children, although the possibility of time poverty is significantly
higher for households with children than those without children, there is no evident tendency that suchpossibility changes depending on the number of children. The relationship with income poverty shows11that households with a larger number of children have a significantly higher possibility of falling into
income poverty.
Concerning the relationship between time poverty and income poverty, the coefficient of income
poverty dummy in the analysis of all households using time poverty as the explained variable issignificantly negative (odds ratio of less than 1). The value in the analysis of married-couple households
only is indicated also as negative but at a low significance level. In this connection, the effect of timepoverty dummy in the analysis using income poverty as the explained variable shows a significantly
negative relationship (odds ratio of less than 1) as well. The value in the analysis of married-couple
households only, however, does not indicate a significant value.
The effect of the householders’ educational background demonstrates that, in all estimation models of
income poverty, that the higher the education received, the less likely the households are to fall into
income poverty. For time poverty, the possibility of falling into time poverty is significantly low for
university or graduate school graduates in the analysis only for the married-couple household. This might
indicate that if educational background of individuals suggests the level of productivity, the higher the
productivity of householders becomes, the better time can be managed and the less susceptible to timepoverty the household becomes. This point, however, demands further examination.
The household heads’ ages imply that the younger they are, the less susceptible to time poverty they are.
The effect of householder age, however, weakens when the number of children in married-couple
households is controlled. As for the effect of householders’ ages on income poverty, no significant effectwas observed from the analysis of all households, or from analysis of married-couple households:
controlling the number of children removes the effect of householder age.

6. Conclusion
This analysis focused on whether people can secure the time required for household life (housework,
child rearing and others), by defining poverty from two dimensions of time and income and estimating thetime poverty level as well as the income poverty level in Japan by using the JHPS data. Many previous
researches have pointed out the enlarging Japanese poverty level, using monetary indicators, but time isalso one of the most important factors determining people’s standard of living and it’s a definite resource
along with money.
There are several researches grasping poverty from two dimensions of income and time in othercountries, but no research has employed this approach in Japan until now. We firstly clarified that
employment statuses of husband and wife and the situation of child-rearing are important factors of timepoverty. Particularly, single-parent households can easily fall into time poverty. In single-parent
households, only one parent is available to undertake child-rearing and working, so it’s very difficult toescape from time shortage without monetary and physical aid. However, this analysis couldn’t include
multi-generational households, such as with a grandparent (who can offer aids), for the data constraint.

12

Therefore, it’s possible to overestimate the time poverty of single-parent households, and it is necessary toinvestigate further analyses using another survey.
As a second point, we confirmed that regarding double-earner couples with children, especially for
double full-time employed parents, the time poverty rate is high, although income poverty rate is low.
As a third point, we estimated the level of income poor after time adjustment by household types. The
normal income poverty rate is 12.5%, but time-adjusted income poverty rate which consideredhouseholds lacking minimum time for the housework and buying homemaker services through the market
amounted to 14.9%, increasing by 2.5 percentage points.
Finally, we describe several policy implications from the estimated results of the analysis. Firstly, thegovernment needs to increase the policy support for single-parents with children because this type ofhousehold confronts severe situations of income poverty and time poverty at a high rate. Job assistance is
one of the important policies as a measure for income poverty. However, as Tamiya and Shikata (2007)shows, the average labor hours of a single-parent is already too long compared to other OECD countries.
Therefore, the assistances related to the direct reduction of their work and/or child-rearing loads areneeded.
Secondly, the child-rearing supports for double-income couples with children are also needed. In recent
years, the increase in the number of child-care facilities in urban areas has been occurring. However, theproblem on ‘waiting baby’ has been continuing in the heart of Tokyo and other large cities. The female
career path which enables them to combine child-bearing at a younger age and career progression afterchild-birth should be more accepted in the society of Japan.

13

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[15]
[16]

[17]
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[19]
[20]
[21]
[22]
[23]
[24]
[25]
[26]
[27]

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Burchardt, T. (2010) “Time, income and substantive freedom: A capability approach,” Time andSociety, 19 (3): 318-344.
Douthitt, R. (2000) “Time to do the chores? Factoring home-production needs into measures ofpoverty,” Journal of Family and Economics Issues, 21 (1) 7-22.
Goodin, R. J., Bittman, R. W. and Saunders, S. (2005) “The time-pressure illusion: Discretionary
time vs free time,” Social Indicators Research, 73: 43–70.
Goodin, R., Rice, J., Parpo, A. and Eriksson, L. (2008) Discretionary Time: A New Measure of
Freedom. Cambridge: Cambridge University Press.
Harvey, A. and Mukhopadhyay, A. K. (2007) “When twenty-four hours is not enough: Timepoverty of working parents,” Social Indicators Research, 82, 57-77.
Ishii, K. and Yamada, A. (2007) “Dynamic analysis of Poverty based on the KHPS data,” Higuchi,
Y., Seko, T. (eds) Dynamism of Household Behavior in Japan, Keio University Press, 101-129. (inJapanese)Ito, S., Amano, H, Amano, H. and Mizunoya, T. (eds) (2005) Lifetime and livelihood welfare,
Koseikan. (in Japanese)
Japan Institute for Labor Policy and Training (2012) “Survey on life environment amonghouseholds with children and employment status of parents,” Investigative report. (in Japanese)
Kalenkoski, C. and Karmrick, K. S. (2013) “How does time poverty affect behavior? A look ateating and physical activity,” Applied Economic Perspectives and Policy, 35 (1): 89-105.
Kalenkoski, C., Karmrick, K. S. and Andrews, M. (2011) “Time poverty thresholds and rates for
the US population,” Social Indicators Research, 104: 129-155.
Komamura, K. (2003) “Estimation of low income household and public assistance system,” Mita
Commerce Research, 46(3):107-126. (in Japanese)
Kuroda, S. and Yamamoto, I. (2011) “When people work?” RIETI Discussion Paper Series
11-J-053. (in Japanese)
McGinnity, F and H, Russell (2007) Gender inequalities in time use: The distribution of caring,housework and employment among women and men in Ireland, The Economics and Social
Research Institute, Dublin, Ireland.
Ministry of Labour Health and Welfare (2006) Guideline of sleeping for health 2014. (in Japanese)
Naoi, M. and Yamamoto, K.(2010) “Sample design and representativeness of JHPS,” Higuchi, Y.,
Miyauchi, T., Mckenzie, C. R. and Panel Data Research Center at Keio University (eds) Dynamism
of Poverty, Keio University Press, 2010, pp.3-27.
OECD (2011) How’s Life? –Measuring well-being, OECD Press.
Vickery, C. (1977) “The time poor: A new look at poverty,” The Journal of Human Resources12(1): 27–48.
Ohtake, F.(2005) Inequality in Japan, Nihon Keizai Shimbun. (in Japanese)
Oshio, T. and Urakawa, K.(2008) “Trend of poverty and redistribution policy in the earliy 2000s in
Japan,” Quarterly of Social Security Research, 44(3): 278-290. (in Japanese)
Tachibanaki, T. (2005) Confronting income inequality in Japan, Cambridge: MIT Press.
Tachibanaki, T. and Urakawa, K.(2006) A Study on Poverty in Japan, University of Tokyo Press..
Tamiya, Y. and Shikata, M.(2007) “Work and Child-care of single mother’s household,” Quarterlyof Social Security Research , 43 (3): 219-231. (in Japanese)
Cabinet Office (ed.) (2013) White paper on children and young people. (in Japanese)
Yano, M.(1998) System of comfortable daily lives-International comparison of life hours, Rengo
multidiscipline laboratory. (in Japanese)

14

Figure 1 Outline of income poverty and time poverty

Table1. Average amounts of minimum living expenses by region(Yen／month）

One-person household
Single-parent with children
Couple with child older than 6
Couple with a child younger than 6
Couple with two or more children younger than 6
Couple without child
Total

Region 1-1, 1-2

Region 2-1, 2-2

Region 3-1, 3-2

mean
121,698
239,611234,897
233,906
242,988
145,122
197,671mean
103,805
189,157
221,643
219,492
218,979
117,536
176,430

mean
79,415
184,202
190,865
190,723
204,127
107,840
158,320

Source: Authors' calculations based on the JHPS2011-2013.

15

N
196
35
420
201
85
254
1,191

N
103
25
265
111
54
202
760

N
63
13
208
109
46
154
593

Table2. Minimum time required for basic activities and houseworks by household types

7days
(V)

(hours)week

Minimum time required for thehousework (T1)

Allocatable
time
Ta
Leisure (V-Te)
Housework Childcare Shopping Total(weekday)(Tm-T1)

Essential time (Te)

Tm

week

day

week

day

day

day

week

week

Couple with children
with children who are all older than 6with one child younger than 6with two or more children younger than 6
Vickery (1977): Couple with one child
Hervey et al. (2006): Couple with one child
Couple without children

336
336
336
336
336
336

165.5
165.5
165.5
162.8
175.0
165.5

2.0
2.0
2.0
2.0
4.0
2.0

170.5
170.5
170.5
173.2
161.0
170.5

5.5
4.0
3.7
4.3

0.4
5.0
6.2
0.1

1.2
1.1
1.0
1.1

50.9
71.3
77.0
62.0
74.6
39.4

119.6
99.2
93.5
111.2
86.4
131.1

Vickery (1977): Couple without children
Single parent with children
Vickery (1977): Single parent with one child336 162.8
168 83.2
168 81.4
168 87.5
168 82.3
168 83.2
168 81.4

2.0
1.0
1.0
2.0
1.0
1.0
1.0

173.2
84.8
86.6
80.5
85.7
84.8
86.6

3.5
2.3
2.3
-

1.1
0.0
0.0
-

1.0
0.6
0.6
-

43.0
39.3
57.0
52.0
21.2
21.2
31.0

130.2
45.5
29.6
28.5
64.5
63.6
55.6

Hervey et al. (2006): Single parent with one child

One-person household (Male)
One-person household (Female)
Vickery (1977)

Note: Household types are categorized according to "Survey on Time Use and Leisure Activities".
Source: Authors' calculations based on the JHPS2011-2013.

Figure2. Total working hours of adults by household types

One person-household (Male)One person-household (Female)Single parent with children
Couple with children who are all older…
(Among them, double earner)
Couple with one preschool child(Among them, double earner)
Couple with two or more preschool…
(Among them, double earner)
Couple without child(Among them, double earner)
0
Source: Authors' calculations based on the JHPS2011-2013.

16

20

40

60

80

100

Figure3. Working situation of couples by household types
80%
Double earners: both are fulltime workers

70%
60%

Double earners: husbands arefull time workers and wifes
are part time workers

50%
40%

Double earners: othercombination

30%
20%

Single earners

10%0%
all children
older than 6onepreschoolchild

two or morepreschool
childrenno child

Both unemployed

Source: Authors' calculations based on the JHPS2011-2013.

Table3. Amounts of leisure and time-poverty rate by household types
Ta-Tw (hours/week) Number of household
Mean

One-person household (Male)
One-person household (Female)Single parent with children
Couple with children who are all older than 6 All
Double earner
Couple with one or more preschool children All
Double earner
Couple without children
All
Double earner

23.0
24.7
6.3
44.9
38.1
28.6
13.6
62.3
42.2

Source: Authors' calculations based on the JHPS2011-2013.

17

Time-poverty
Number of
ratehousehold in timepoverty(%)(Ta-Tw<0)

S.D.

24.2
24.2
19.9
25.8
24.6
24.3
25.4
35.3
25.8

221
141
73
893
656
606
239
610
369

23
20
29
43
42
73
67
20
20

10%
14%
40%
5%
6%
12%
28%
3%
5%

Figure4. Frequency of having dinner together with children

Not time-poverty
Almost 0days aweek
2%Time-poverty
Almost 0days aweek
5%

1-2 days
a week17%

3-4 days
a week14%

1-2 days a
week
25%

Almosteveryday62%

5-6 days
a week5%

Almosteveryday49%

3-4 days a
week
12%

5-6 days aweek
9%Source: Authors' calculations based on the JHPS2011-2013.

Table4. Time-poverty rate and income-poverty rate

One-person household (Male)
One-person household (Female)Single parent with children
Couple with children who are Double earners: both are full time
all older than 6 yrs oldworkers
Double earners: husbands are full time
and wifes are part time
Double earners: others
Single earner
Both unemployed
Couple with one or more
Double earners: both are full timepreschool children
workers

Double earners: husbands are full time
and wifes are part time
Double earners: others
Single earner
Both unemploted

Couple without child

Double earners: both are full time
workers
Double earners: husbands are full time
and wifes are part time
Double earners: others
Single earner
Both unemployed
Total

Time
Both income- andpoverty
time-poverty
10.4%
0.0%
14.2%
2.8%
39.7%
28.8%

221
141
73

Incomepoverty
15.4%
24.1%
75.3%

98

3.1%

17.3%

0.0%

387
171
233
4

5.2%
19.9%
10.3%
-

2.6%
8.8%
0.4%
-

0.0%
0.6%
0.0%
-

60

8.3%

56.7%

5.0%

109
70
366
1

12.8%
30.0%
13.9%
-

16.5%
21.4%
1.6%
-

2.8%
2.9%
0.3%
-

116

1.7%

7.8%

0.9%

120
133
197
44
2,544

0.0%
3.0%
4.6%
12.5%

2.5%
6.0%
0.0%
8.2%

0.0%
0.0%
0.0%
1.4%

N

Note：The poverty rates are not shown when the numbers of observation are less than 50.
Source: Authors' calculations based on the JHPS2011-2013.

18

Table5. Two-dimensional poverty rates by household types
Income-poverty

Not poor
One-person household
Single parent with children
Couple with children who are all older than 6
Couple with one or more preschool children
Couple without child
Total

70.4%
13.7%
86.0%
74.3%
93.6%
80.7%

Time-poverty
Not income
Income poor
Income poor
Both income
poor but timeafter time
but not time
and time poor
poor
adjusted
poor
17.7%
1.1%
5.2%
5.5%
46.6%
28.8%
2.7%
8.2%
9.2%
0.1%
1.5%
3.2%
13.7%
1.5%
4.1%
6.4%
3.1%
0.2%
0.3%
2.8%
11.1%
1.4%
2.4%
4.4%

Source: Authors' calculations based on the JHPS2011-2013.

19

Table6. Summary statistics

Time-poverty dummy
Income-poverty dummy
One-sided poverty dummyHousehold type
One-person household
Single-parent with children
Couple with children who are all older than 6
Couple with one or more children younger than 6
Couple without child (ref)Working conditions of couples
Double earner: both employed full time
Double earner: full time employed hasband and part-time employed wife
Double earner: both self-employed
Double earner: full time employed husband nad self-employed wife
Double earner: other combinations
Single earner (ref)Both unemployed
Number of children
zero (ref)one child
two or more children
Householders' educational level
High school graduate
Two-year college and technical school
Four-year college and graduate school (ref)Householdres' age category
20's
30's
40's
50's
60's (ref)Area of living as the regional category of welfare benefit
Region 1-1 (ref)Region 1-2
Region 2-1
Region 2-2
Region 3-1
Region 3-2
Survey year
2011 dummy
2012 dummy
2013 dummy (ref)Source: Authors' calculations based on the JHPS2011-2013.

20

All households
Married-couple household
N
mean
S.D.
N
mean
S.D.
2,462
0.08
0.28
2,032
0.06
0.25
2,462
0.13
0.33
2,032
0.09
0.29
2,462
0.20
0.40
2,032
0.15
0.36
2,462
2,462
2,462
2,462
2,462

0.15
0.03
0.36
0.24
0.23

0.35
0.17
0.48
0.42
0.42
2,032
2,032
2,032
2,032
2,032
2,032
2,032

0.12
0.30
0.04
0.05
0.38
0.37
0.02

0.33
0.46
0.20
0.22
0.49
0.48
0.15

2,032
2,032
2,032

0.28
0.20
0.52

0.45
0.40
0.50

2,462
2,462
2,462

0.41
0.16
0.43

0.49
0.36
0.50

2,032
2,032
2,032

0.40
0.15
0.45

0.49
0.36
0.50

2,462
2,462
2,462
2,462
2,462

0.05
0.29
0.35
0.18
0.12

0.23
0.45
0.48
0.39
0.33

2,032
2,032
2,032
2,032
2,032

0.04
0.30
0.38
0.18
0.11

0.19
0.46
0.48
0.39
0.31

2,462
2,462
2,462
2,462
2,462
2,462

0.29
0.18
0.23
0.07
0.17
0.06

0.46
0.38
0.42
0.26
0.38
0.24

2,032
2,032
2,032
2,032
2,032
2,032

0.28
0.18
0.23
0.07
0.18
0.06

0.45
0.39
0.42
0.26
0.39
0.24

2,462
2,462
2,462

0.38
0.33
0.29

0.48
0.47
0.46

2,032
2,032
2,032

0.38
0.33
0.29

0.49
0.47
0.46

Table7. Logit analysis of time-poverty and income-poverty (All household types)
Model.

Household type
One-person household
Single-parent with children
Couple with children who are all older than 6
Couple with one or more children younger than 6
Couple without child (ref)Income-poverty dummy
Time-poverty dummyHouseholders' educational level
High school graduate
Two-year college and technical school
Four-year college and graduate school (ref)Householdres' age category
20's
30's
40's
50's
60's (ref)Area of living as the regional category of welfare benefit
Region 1-1 (ref)Region 1-2
Region 2-1
Region 2-2
Region 3-1
Region 3-2
Survey year
2011 dummy
2012 dummy
2013 dummy (ref)N
Log likelihood
Pseudo R

21Time-poverty
odds ratioz3.52 ***
23.90 ***
1.13
3.06 ***

4.15
7.90
0.39
3.74

0.58 **-2.17

2
Income-poverty
odds ratioz6.50 ***
104.01 ***3.15 ***
4.70 ***

6.68
11.65
4.02
5.22

0.59 **-2.04

3
One-sided poverty
odds ratioz5.40 ***
78.29 ***
2.13 ***
3.90 ***

7.85
11.07
3.52
6.11

0.93
0.76

-0.43
-1.18

2.35 ***
2.14 ***

5.48
3.88

1.66 ***
1.25

4.11
1.32

5.39 ***
4.71 ***
4.71 ***
4.27 ***

3.13
3.13
3.13
2.86

1.07
1.49
0.70
1.01

0.18
1.39
-1.20
0.02

1.80 *
2.25 ***
1.33
1.56 *

1.93
3.21
1.11
1.70

0.68 *
0.54 ***
0.96
0.80
0.77

-1.69
-2.71
-0.12
-0.97
-0.77

0.99
0.54 ***
0.32 ***
0.56 ***
0.31 ***

-0.05
-3.20
-3.50
-2.76
-3.36

0.94
0.59 ***
0.57 **
0.68 **
0.43 ***

-0.43
-3.32
-2.37
-2.21
-3.13

1.12
1.06

0.58
0.31

1.20
1.08

1.10
0.47

1.12
1.01

0.82
0.08

2462
-629.410.102

2462-778.05
0.170

Source: Authors' calculations based on the JHPS2011-2013.
Note: *** refers to a significant level at 1%, while ** is at 5% and * at 10%.

21

2462
-1045.74
0.140

Table8. Logit analysis of time-poverty and income-poverty (Married-couple households)
4Time-poverty
odds ratiozWorking conditions of couples
Double earner: both full time employed
Double earner: full time employed hasband
and part-time employed wife
Double earner: both self-employed
Double earner: full time employed husband
and self-employed wife
Double earner: other combinations
Single earner (ref)Number of children
zero (ref)one child
two or more children
Income-poverty dummy
Time-poverty dummyHouseholders' educational level
High school graduate
Two-year college and technical school
Four-year college and graduate school (ref)Householdres' age category
20's
30's
40'
50's
60's (ref)Area of living as the regional categoryof welfare benefit
Region 1-1 (ref)Region 1-2
Region 2-1
Region 2-2
Region 3-1
Region 3-2
Survey year
2011 dummy
2012 dummy
2013 dummy (ref)N
Log likelihood
Pseudo R

2

41.81 ***

5
Income-poverty
odds ratioz8.85

0.42 **

-4.75

0.21

***
***

0.21

***

32.47

***

6.76

2.94

5.68

***

2.87

0.68

31.54

***

3.22 ***
2.90 ***
0.49 *

7.27

2.44

***

3.45
3.43
-1.86

6
One-sided poverty
odds ratio
z

-2.26

3.52 ***

6.23

-5.35

0.18

***

-7.09

3.40

5.79

***

6.15

-0.95

1.10

0.30

3.35

5.01

***

6.95

2.34 **
6.62 ***

2.18
5.29

2.66 ***
4.78 ***

3.74
6.51

0.65

-1.16

0.72
0.52 **

-1.48
-2.04

1.81 ***
1.54 *

3.16
1.80

1.33 *
1.03

1.92
0.15

6.05
14.88 ***
6.20 *
4.89

1.49
2.57
1.73
1.50

3.04 *
2.19
0.90
1.58

1.90
1.53
-0.22
0.92

4.09 ***
4.23 ***
1.69
2.24 *

2.79
3.37
1.22
1.88

0.96
0.62
1.68
0.97
0.47 *

-0.13
-1.53
1.36
-0.10
-1.66

1.00
0.68 *
0.41 **
0.87
0.47 *

0.01
-1.65
-2.21
-0.55
-1.83

1.02
0.65 **
0.80
0.86
0.42 ***

0.12
-2.22
-0.80
-0.75
-2.58

1.30
1.25

1.06
0.89

1.37
1.18

1.56
0.76

1.29
1.17

1.55
0.91

2032
-376.230.225

2032-540.06
0.147

Source: Authors' calculations based on the JHPS2011-2013.
Note: *** refers to a significant level at 1%, while ** is at 5% and * at 10%.

22

2032
-751.020.140