This PDF is a selection from a published volume from the National Bureau of
Economic Research
Volume Title: NBER Macroeconomics Annual 2008, Volume 23
Volume Author/Editor: Daron Acemoglu, Kenneth Rogoff and Michael
Woodford, editors
Volume Publisher: University of Chicago Press
Volume ISBN: 0-226-00204-7
Volume URL: http://www.nber.org/books/acem08-1
Conference Date: April 4-5, 2008
Publication Date: April 2009
Chapter Title: Marriage and Divorce since World War II: Analyzing the Role of
Technological Progress on the Formation of Households
Chapter Author: Jeremy Greenwood, Nezih Guner
Chapter URL: http://www.nber.org/chapters/c7282
Chapter pages in book: (p. 231 - 276)
4
Marriage and Divorce since World War II:
Analyzing the Role of Technological Progress
on the Formation of Households
Jeremy Greenwood, University of Pennsylvania and NBER
Nezih Guner, Universidad Carlos III de Madrid, CEPR, and IZA
I. Introduction
Consider the following two facts that have helped reshape U.S. house-
holds over the last 50 years:
1. A smaller proportion of the adult population is now married com-
pared with 50 years ago (fig. 1).
1
In 1950, 82% of the female population
was married (out of nonwidows between the ages of 18 and 64). By 2000
this had declined to 62%. Adults now spend a smaller fraction of their
lives married. In 1950 females spent about 88% of their life married as
compared with 60% in 1995. Underlying these facts are two factors:
a) Between 1950 and 1990, the divorce rate doubled from 11 to 23 di-
vorces per 1,000 married women (between the ages of 18 and 64; see
fig. 2).
b) At the same time, the marriage rate declined. Exactly how much
is somewhat sensitive to the particular age group use d in the de-
nominator for the calculations. In 1950 there were 211 marriages
per 1,000 unmarried women as compared with just 82 in 2000 (again,
out of nonwidows between the ages of 18 and 64).
2. The amount of time allocated to market work by married households
has increased markedly over the postwar period (see fig. 3). This is
mainly due to a rise in labor force participation by married females.
In particular:
a) In 1950 a married household in the 2454yearold age group spent
working in the market 25.5 hours per week per person, compared
with 31.3 hours per week in a single household. Thus, singles worked
more in the market on average than married couples. At the time, only
23.7% of married women worked, compared with 78% of single ones.
© 2009 by the National Bureau of Economic Research. All rights reserved.
9780226002040/2009/20080401$10.00
b) By the year 1990 labor effort expended per person by married house-
holds had risen to 33.5 hours per week. This exceeded the 30.6 hours
spent by a single household. Almost as many married females were
participating in the labor market (71%) as single ones (80%).
What economic factors can explain these facts? The idea here is that
technological progress played a major role in inducing these changes.
2
Two hundred years ago the United States was largely a rural economy.
The household was the basic production unit, with the family produc-
ing a large fraction of what it consumed. At the time, most marriages
were arranged by the parents of young adults. Key considerations were
whether or not the potential groom would be a good provider and the
bride a good housekeeper.
3
Over time more and more household goods
and services could be purchased outside the home, such as packaged
foods and readymade clothes. Additionally capital goods, ranging from
washing machines to microwave ovens, were brought into the home,
greatly reducing the time needed to maintain a household. This had
two effects. First, it allowed all adults, both married and single, to devote
more time to market activities and less to household production. Second,
it lowered the economic incentives to get married by reducing the benefits
Fig. 1. Marriage, 19502000
Greenwood and Guner232
of the traditional specialization of women at housework and of men at
market work. The reduction of the economic benefits of marriage al-
lowed the modern criteria of mutual attraction between mates to come
to the fore, a trend from economics to romance in the words of Ogburn
and Nimkoff (1955).
To model this idea formally, a Becker (1965)cumReid (1934) model
of household production is embedded into a Mortensen (1988) style
spousalsearch model. Three key ingredients are injected into this frame-
work. First, there are economies of scale in household consumption and
production. Second, it is assumed that purchased household inputs and
labor are substitutes in household production. Third, it is presumed that
nonmarket goods exhibit stronger diminishing marginal utility than
market goods. Some theoretical results are established for this frame-
work. The economies of scale in household consumption and production
provide an economic motive for marriage. It pays f or a couple to pool
their resources together. Now, suppose that the price of purchased house-
hold inputs declines over time. Labor will be displaced from the home,
given that household inputs and labor are substitutes in household pro-
duction. Furthermore, if there is stronger diminishing marginal utility in
nonmarket goods visàvis market goods, then married households will
allocate a smaller fraction of their spending on the inputs for household
Fig. 2. Rates of marriage and divorce, 19502000
Marriage and Divorce since World War II 233
production than less well off single households. As a consequence, single
households gain the most from a decline in the price of purchased house-
hold inputs. Thus, a fall in the price of purchased household inputs
causes the relative benefits of single life to increase. Singles searching
for a spouse will become pickier. For those currently married, the value
of a divorce will rise, because the value of becoming single is higher.
Thus, the theoretical analysis suggests that the framework developed
has promise for explaining the observed rise in the number of single
households, together with the increase in hours worked by married ones.
To gauge the quantitative potential of the framework, the model is
solved numerically. The models predictions for the time paths of labor
force participation and vital statistics are compared with the U.S. data.
It is found that the developed framework can potentially explain a sub-
stantial portion of the rise in divorce, the fall in marriage, and the increase
in married female labor force participation that occurred during the later
half of the twentieth century.
Interestingly, the fraction of the p opulation t hat is married did not
show a monotonic decline over the course of the entire twentieth century.
Fig. 3. Household hours worked and female labor force participation, 195090
Greenwood and Guner234
It actually increased during the baby boom years. This resulted in a
humpshaped time path for marriage during the last century. Is this ob-
servation congruent with theory presented here? The answer is yes. It is
demonstrated that a simple extension of the basic framework has the po-
tential to address this fact. It does so by linking a young adults decision
to leave home and search for a mate with technological progress in the
household sector. The extension can explain the drop in the number of
young adults living with their parents over the last 100 years.
A prediction of the framework is that household size should decline
when the price of purchas ed household inputs falls. The relationship
between household size and the price of household appliances is exam-
ined econometrically for a small cross section of Western countries. A pos-
itive association is found, in accordance with the theorys prediction. This
finding complements recent work by Cavalcanti and Tavares (2008), who
report that female labor supply is negatively associated with the price of
household appliances in a panel of co untries. Algan and Cahuc (2007)
also find that it is related to the labor supply of you nger and older
(nonprimeage) workers, but in a way that interacts with cultural differ-
ences across countries. Likewise, CoenPirani, Leon, and Lugauer (2008)
conclude, using U.S. Census micro data, that a significant portion of the
rise in married female labor force participation during the 1960s can be
attributed to the diffusion of household appliances.
It needs to be stated upfront that the goal of the analysis is not to
simulate an allinclusive model of household formation and labor force
participation. Rather, the idea here is to see whether or not the simple
mechanisms put forth have the potential quantitative power to explain
the postwar observations on household formation and labor force par-
ticipation. This is done without regard to the many other possible ex-
planations for the same set of factssome of which could be embedded
into a more general version of the developed framework. Theory, by its
essence, is a process of abstraction. Therefore, some factors that may be
important for understanding the phenomena under study have been
deliberately left out of the analysis, for purposes of both clarity and trac-
tability; see Stevenson and Wolfers (2007) for a recent survey on marriage
and divorce.
For example, the tremendous amount of technological progress in
contraception that occurred over the last century greatly reduced the risk
of outofwedlock sexual relationships. It seems very likely that this pro-
vided impetus for the fall in marriage and the rise in divorce that occurred
since World War II. It might be hard for a theory based on improvements
in contraception alone, however, to explain the humpshaped time path
Marriage and Divorce since World War II 235
for marriage that occurred over the entire century. The liberalization of
divorce laws in the 1970s is often thought of as being a prime candidate
for causing the rise in divorce. The adoption of nofault unilateral divorce
laws by many states in the 1970s coincides well with the rise of the di-
vorce rate during the same period. The empirical evidence on the effect
of divorce laws is controversial, however. A recent study by Wolfers
(2006) finds that, once transitional dynamics are appropriately controlled
for, unilateral divorce laws explain very little of the longrun rise in di-
vorce rates. Furthermore, except for a spike associated with World War II,
the rate of divorce rose more or less continuously over the last century
from about four per 1,000 women in 1900, to about 10 in 1941 (a doubling),
to about 23 today (another doubling) . (In fact, Ogburn and Nimkoff
[1955] write about the early trend.) So, there seems to be room in the lit-
erature for the explanation proposed here that technological advance in
the household sector contributed to the rise in divorce and the decline in
marriage.
II.
The Economic Environment
The economy is populated by a continuum of males and females, each
sex with unit mass. Individuals have finite lives. Specifically, at the be-
ginning of each period an individual faces the constant probability of
dying, δ. Thus, δ people of each sex die each perio d. The individuals
who have passed on are replaced by a newly born generation of exactly
the same size. There are two types of individuals: those who are single
and those who are married. Each individual is endowed with one unit
of time, which can be divided between market and nonmarket work. A
unit of market work pays the wage rate, w. At the beginning of each
period, singles participate in a marriage market, assuming that they
have survived. Each single is randomly paired up with someone else.
The prospective couple then draws a certain level of suitability or qual-
ity, b, from a fixed distribution. The question facing a single is, should
she or he marry or wait until a better match comes along? For a married
couple, match quality evolves over time, according to some fixed distri-
bution. Fo r simplicity, assume that married couples die together at the
start of a period with probability δ. If they survive, then they must decide
whether or not to remain married. After the marriage and divorce deci-
sions, indi vidual s e nter the labor mark et. A single agent must decide
how much of his or her one unit of time to devote to market work. A mar-
ried couple must determine how much of their two units of time to spend
Greenwood and Guner236
in the labor force. For simplicity, it is assumed that ther e are no asset markets.
Hence, there is no borrowing or lending, and so forth, in the economy.
Finally, as will become clear, there are no matching externalities present
in the model. The aggregate state of the marriage market will not influ-
ence a households decision making.
A.
Production
Start with production. Two types of goods are produced, market and
nonmarket ones.
1.
Household Production
Suppose that nonmarket goods, n, are produced in line with the follow-
ing household production function:
n ¼½θd
κ
þð1 θÞh
κ
1=κ
for 0 < κ < 1; ð1Þ
where d denotes purchases of household inputs, and h is the amount of
time spent on housework. Let purchased household inputs sell at price
p, measured in terms of time. The idea here is that over time p will drop.
Specifically, let p fall monotonically to some lower bound
p > 0. In re-
sponse households will substitute out of using labor toward using more
purchased inputs. Note that it has been assumed that purchased inputs
and time are more substitutable in production than CobbDouglas, that
is, κ > 0. Hence, as p declines, household production will become more
goods intensive and less labor intensive. Examples of laborsaving house-
hold inputs abound: disposable diapers, frozen foods, microwave ovens,
washing machines, and Tupperware.
2.
Market Production
Market goods are produced in line with the constantreturns toscale
production technology
y ¼ wl; ð2Þ
where y is aggregate output and l is aggregate employment. Given the
linear form for the aggregate production function, w will represent the
real wage rate in equilibrium. Real wages will grow over time. In par-
ticular, suppose that w increases monotonically to some finite upper
bound
w. There is no physical or, as mentioned, financial capital in the
Marriage and Divorce since World War II 237
economy. Market output y is used for two purposes, namely, direct con-
sumption and as an input int o household production. Specifically, one
unit of output can be used to produce one unit of final consumption
or 1=ðwpÞ units of household inputs. Thus, the economys resource con-
straint reads
c þ wpd ¼ y;
where c and d represent aggregate consumption and purchases of house-
hold inputs, respectively.
B.
Tastes
Singles. Let the momentary utility function for a single read
U
s
ðc; nÞ¼α ln ðc cÞþð1 αÞn
ζ
=ζ; with 0 < α < 1; ζ < 0 c:
Here c and n denote the persons consumption of market and nonmarket
goods, respectively. The constant c is a fixed cost associated with main-
taining a household. This represents the first of two sources of scale
economies in household consumption. Note that the utility function
for nonmarket goods is more concave than the ln function (i.e., ζ < 0).
The importance of this restriction will become clear as the theory is de-
veloped. This constraint is not imposed in the quantitative analysis.
Therefore, the data will speak to the sign and magnitude of ζ. If a single
dies, he realizes a utility level of zero in the afterlife, an innocuous nor-
malization. Leisure has been excluded from the tastes. This is in line with
the Beckerian (1965, 504) theory of household production since although
the social philosopher might have to define precisely the concept of lei-
sure,theeconomistcanreachallhistraditionalresultsaswellasmanymore
without introducing it at all. The idea here is that often all one cares about is
time spent in the market versus at home, and the above framework will cap-
ture this through the production side of things. Additionally, observe that
a separable form for the utility function is chosen, as is conventional in
macroeconomics. This minimizes the role placed on home production.
Married individuals. Tastes for a married individual are given by
U
m
ðc; nÞþb ¼ α ln ½ðc cÞ=2
ϕ
þð1 αÞðn=2
ϕ
Þ
ζ
=ζ þ b; with 0 < ϕ < 1;
where c and n represent the house holds consumption of market and
nonmarket goods. To determine an individuals consumption, c c and
n are divided by the household equivalence scale, 2
ϕ
, to get consumption
per member, ðc cÞ=2
ϕ
and n=2
ϕ
. Since 0 < ϕ < 1, this implies that it is
Greenwood and Guner238
less expensive to provide the second member of the household with con-
sumption than it is the first. This is the second source of economies of scale
in consumption. Observe that the bliss from a match, b, can be negative.
Finally, if a married couple die, they realize a zeroutility level thereafter.
C.
Match Quality
Recall that when singles meet t hey draw a match quality b.Suppose
that b is normally distributed so that
b Nðμ
s
; σ
2
s
Þ;
where μ
s
and σ
2
s
are the mean and variance of the singles distribution.
Let the cumulative distribution function that singles draw from be rep-
resented by SðbÞ. Likewise, each period a married couple draws a new
value for the match quality variable, b. Suppose that last period the cou-
ple had a match quality of b
1
. Now, assume that b evolves according to
the following autoregressive process:
b ¼ð1 ρÞμ
m
þ ρb
1
þ σ
m
ffiffiffiffiffiffiffiffiffiffiffiffiffi
1 ρ
2
p
ξ; with ξ Nð0; 1Þ:
Here μ
m
and σ
2
m
denote the longrun mean and variance for the process
b. The parameter ρ is the coefficient of autocorrelation. Write the (con-
ditional) cumul ative distribution function that married couples draw
from as Mðbjb
1
Þ.
III.
Household Decision Making
How will a single agent divide his or her time between market and non-
market work? When will he or she choose to get married? Likewis e,
how will a married couple split their time between market work and
housework? When will they choose to divorce? To answer these ques-
tions, let VðbÞ denote the expected lifetime utility for an individual who
is currently in a marriage with match quality b . Similarly, W will repre-
sent the expected lifetime utility for an agent who is single today. Imag-
ine that two singles meet and draw a match qu ality of b. They will
choose to marry if VðbÞ W and to remain single if VðbÞ < W. Likewise,
consider a married couple with match quality b. They will choose to re-
main married when VðbÞ W and choose to divorce if VðbÞ < W. Thus,
the marriage and divorce decisions are summarized by table 1. Note that
given the absence of asset markets, b will be the only state variable at the
individual level that is relevant for determining expected lifetime utility.
Marriage and Divorce since World War II 239
At the aggregate level, prices and wage s will also matter. R ecall that
wages are rising over time and that prices are falling. Thus, W and V are
functions of time. Given this, W
and V
will denote the value functions for
single and married lives that obtain next period; that is, the prime symbol
connotes these functions dependence on time. So, how are the functions
VðbÞ and W determined? This question will be addressed next.
A.
Singles
The dynamic programming problem for a single agent appears as
W ¼ max
c; n; d; h
U
s
ðc; nÞþβ
Z
max ½V
ðb
Þ; W
dSðb
Þ
ðP1Þ
subject to
c ¼ w ð1 hÞwpd ð3Þ
and (1). The discount factor β reflects the probability of dying. That is, if
β
~
is the persons subjective discount factor, then β ¼ð1 δÞβ
~
. Observe
that while the individual is single today, the agent picks married or sin-
gle life next period to maximize welfare, as the term max ½V
ðb
Þ; W
in
(P1) makes clear. Again, recall that the value functions are dependent
on technology and hence time. Therefore, for a given level of match qual-
ity, b, the value function will return a different level of expected utility
tomorrow versus today. This dependence of the value functions on time
is implicitly indicated through the use of the prime symbols attached to V
and W, which differentiates their functional forms tomorrow from their
forms today. Since SðbÞ is some fixed distribution, the aggregate state of
the marriage market does not affect the individuals decision making.
B.
Couples
The dynamic programming problem for a married couple reads
VðbÞ¼ max
c; n; d; h
U
m
ðc; nÞþb þ β
Z
max ½V
ðb
Þ; W
dMðb
jbÞ
ðP2Þ
Table 1
Marriage and Divorce Decisions
Single Married
Marry if VðbÞ W Remain married if VðbÞ W
Remain single if VðbÞ < W Divorce if VðbÞ < W
Greenwood and Guner240
subject to
c ¼ w ð2 hÞwpd ð4Þ
and (1). Problem (P2) is similar in structure to problem (P1) with three
differences: (i) the utility function for married agents differs from that
for single agents because of scale effects in household consumption;
(ii) a married couple realizes bliss from marriage, and this is autocorre-
lated over time; and (iii) the couple has two units of time to allocate be-
tween market and nonmarket work. Again, note that while an individual
is married today, the agent chooses married or single life next period to
maximize welfare. Finally, the aggregate state of the marriage market
does not impinge on the couples decision making because Mðb
jbÞ is a
fixed distribution.
IV.
Equilibrium
Formulating an equilibrium to the above economy is surprisingly simple.
First, given the linear market production function (2), there is no need to
determine the equilibrium wage, w. Second, since there are no financial
markets, there is no interaction between households other than through
the marriage market. As far as consumption and p roduction are con-
cerned, each household is an island unto itself. Also, there are no match-
ing externalities in the model. Each s ingle is matched with a potential
mate each period. This pair then draws a quality for the match, b, from
the fixed distribution SðbÞ. Likewise, the b for a couple evolves according
to the fixed distribution Mðb
jbÞ. Hence, household decision making is
not influenced by the aggregate state of the marriage market. Therefore,
characterizing an equilibrium for the economy amounts to solving the
programming problems (P1) and (P2). Thus, it is easy to establish that
an equilibrium for the above economy both exists and is unique.
Vi tal statistics. Computing vital statistics for the economy is a rela-
tively straightforward task. Suppose that the economy exits the previous
period with the (nonnormalized) distribution M
1
ðb
1
Þ over match qual-
ity for married agents of a particular sex. The fractions of agents (of a par-
ticular sex) who were married and single last period, m
1
and s
1
, are
therefore given by m
1
¼
R
dM
1
ðb
1
Þ and s
1
¼ 1
R
dM
1
ðb
1
Þ.Now,
at the beginning of the current period the fraction δ ofthepopulacedies.
These people are replaced by newly born single agents. All agents will
then take a draw, b, for their match quality. After this, they will make their
marriage and divorce decisions i n li ne with table 1. Define the set o f
Marriage and Divorce since World War II 241
match quality shocks for which it is in an individuals best interest to live
in a married household, or M,by
M ¼fb : VðbÞ Wg:
The currentperiod distribution over match quality for married agents, or
MðbÞ, will then read
4
MðbÞ¼ð1 δÞ
ZZ
M½;b
dMðb
~
jb
1
ÞdM
1
ðb
1
Þ
þðs
1
þ δm
1
Þ
Z
M½;b
dSðb
~
Þ: ð5Þ
Therefore, the fractions of agents who are married and single in the current
period, m and s,aregivenbym ¼
R
dMðbÞ and s ¼ 1
R
dMðbÞ.Thefraction
of people getting married in the current period is ðs
1
þ δm
1
Þ
R
M
dSðb
~
Þ,
and the proportion going through a divorce is given by
ð1 δÞ
Z
M
c
Z
dMðb
~
jb
1
ÞdM
1
ðb
1
Þ;
where M
c
is the complement of M.
V.
Qualitative Analysis
It is now time to entertain the following two questions, at least at a theo-
retical level:
1. How does technological progress affect the amount of time spent on
housework?
2. How does tec hnologi cal progress affect the economic ret urn from
married versus single life?
A.
The Time Allocation Problem
The problem. To this end, consider the time allocation problem that faces
a household of size z. It is static in nature and appears as
Iðz; p; wÞ¼ max
c; n; h; d
α ln
c c
z
ϕ
þð1 αÞ
n
z
ϕ
ζ
.
ζ
ðP3Þ
subject to
c c ¼ w ð z hÞwpd c ð6Þ
Greenwood and Guner242
and
n ¼½θd
κ
þð1 θÞh
κ
1=κ
:
Observe that versions of problem (P3) are embedded into (P1) and (P2),
a fact that can be seen by setting z ¼ 1 and z ¼ 2.
The solution. By using the constraints for c c and n in the objective
function (P3) and then maximizing with respect to d and h, the follow-
ing two firstorder conditions obtain:
α
c c
wp ¼ð1 αÞz
ϕζ
½θd
κ
þð1 θÞh
κ
ζ=κ1
θd
κ1
ð7Þ
and
α
c c
w ¼ð1 αÞz
ϕζ
½θd
κ
þð1 θÞh
κ
ζ=κ1
ð1 θÞh
κ1
: ð8Þ
These two firstorder conditions have standard interpretations. For in-
stance, the lefthand side of (7) represents the marginal cost of an extra
unit of purchased household inputs, d. The marginal unit of purchased
household inputs costs wp in terms of forgone market consumption. Since
an extra unit of market consumption has a utility value of α=ðc cÞ, this
leads to a sacrifice of ½α=ðc cÞwp in terms of forgone utility. Likewise,
the righthand side of this equation gives the marginal benefit of an extra
unit of purchased household inputs. These extra goods will increase
household production by ½θd
κ
þð1 θÞh
κ
1=κ1
θd
κ1
. The marginal util-
ity of n onmarket goods is ð1 αÞz
ϕζ
n
ζ1
. Thus, the marginal benefit
of an extra unit of purchased household inputs is
ð1 αÞz
ϕζ
n
ζ1
½θd
κ
þð1 θÞh
κ
1=κ1
θd
κ1
;
which is the righthand side of (7). The two firstorder conditions (7) and
(8), in conjunction with the budget constraint (6), determine a solution for
c, d, and h.
B.
Results
Everything is now set up to address the two questions posed at the start
of this section.
1.
Technological Progress and Time Allocations
So, how does technological progress affect the amount of time allocated
to homework? First, a fall in the price of purchased household inputs, p,
Marriage and Divorce since World War II 243
leads to a reduction in the amount of housework, h, and a rise in the
amount of market work, z h. When the price of purchased household
inputs drops, ho useholds move away from using labor in househo ld
production toward using goods (given the assumption that production
exhibits more substitutability than CobbDouglas or that κ > 0). Second,
a rise in wages, w, leads to an increase in the amount of housework, h,
done. At low levels of income, the marginal utility of market goods is
high because of the fixed cost of household maintenance, c. Thus, people
devote a lot of time to laboring in the market. As wages increase, the fixed
cost for household maintenance bites less and people relax their work
effort in the market. Proposition 1 formalizes all of this.
Proposition 1. Housework, h,is
i) increasing in the price of household commodities, p;
ii) decreasing in the fixed cost of household maintenance, c; and
iii) increasing in real wages, w (when c > 0).
Proof. See the appendix.
Remark. Real wages, w, will have no effect on time allocations in the
absence of a fixed cost for household maintenance, c, that is, when c ¼ 0.
To see this, substitute (6) into (7) and (8) and note that the first order con-
ditions depend on c=w. Thus, as the economy develops, the imp act of
wages on housework will vanish, since c=w 0asw .
2.
Household Size and Allocations
Can anything be said about the allocations (c, d, h) within a twoperson
household visàvis a oneperson household ? The lemma below pro-
vides t he answer, w here the superscripts m and s are attached to the
allocations for married and single households. Before proceeding, note
that the lemma is a key step along the road to proving that a fall in the
price for purchased household inputs reduces the utility differential be-
tween married and single life, when the amount of marital bliss is held
fixed. It shows that a married househ old spends less on purchased
household inputs, relative to market consumption (over and above
the fixed cost of household maintenance), than a single one. Likewise,
the corollary to the lemma is instrumental for establishing that a rise in
wages reduces the economic benefit from marriage. It proves that a
married household consumes more market goods than a single house-
hold does.
Greenwood and Guner244
Lemma 1. The allocations in married and single households have
the following relationships:
i) c
m
c > ½ð2 c=wÞ= ð1 c=wÞðc
s
cÞ;
ii) d
m
< ½ð2 c=wÞ=ð1 c=wÞd
s
;
iii) h
m
< ½ð2 c=wÞ=ð1 c=wÞh
s
.
The above relationships hold even when c ¼ 0. They adhere with equal-
ity when ζ ¼ 0.
Proof. Again, see the appendix.
Corollary. Married households consume more market goods than
single households:
i) ðc
m
cÞ=2
ϕ
> c
s
c;
ii) c
m
> c
s
.
The above relationships hold even when c ¼ ζ ¼ 0.
Proof. See the appendix.
Now, note that a married household has 2 c=w units of disposable
time, after netting out the fixed cost of household maintenance, to spend
on various things. A single household has 1 c=w unit s of disposable
time. Lemma 1 states that a married household will spend a larger frac-
tion of its adjusted time endowment on the consumption of market goods
than a single household will. The lemma also implies that married house-
holds spend less than single households do on household inputs, rela-
tive to market goods. That is, wpd
m
=ðc
m
cÞ < wpd
s
=ðc
s
cÞ and wh
m
=
ðc
m
cÞ < wh
s
=ðc
s
cÞ so that ðwpd
m
þ wh
m
Þ=ðc
m
cÞ < ð wpd
s
þ wh
s
Þ=
ðc
s
cÞ, at least when ζ < 0. When nonmarket good s exhibit strong di-
minishing marginal utility, bigger households will favor (relative to the
consumptionpatternsofsmallerones)theuseofmarketconsumption
for their larger adjusted endowments of time. Part i of the corollary states
that after the fixed cost of household maintenance is paid, market con-
sumption per person is effectively higher in a married household than
in a single one. Also, married households spend more in total on market
goods than single households.
3.
Technological Progress and the Economic Benefits of Married
versus Single Life
Finally, how does technological progress affect the utility differential
between married and single life (with the amount of marital bliss held
fixed)? To address this, let u
m
denote the level of momentary utility realized
Marriage and Divorce since World War II 245
from married life, without marital bliss, and u
s
represent the level of util-
ity realized from single life. From problem (P3) it is apparent that u
m
¼
Ið2; p; wÞ and u
s
¼ Ið1; p; w Þ.
Proposi tion 2. The utility differential between married and single
life (without marital bliss), u
m
u
s
,is
i) increasing in the price of purchased household inputs, p, and
ii) decreasing in real wages, w (when c > 0).
Proof. The first part of the proposition can be established by apply-
ing the envelope theorem to problem (P3). It can be calculated that
dðu
m
u
s
Þ
dw
¼αw
d
m
c
m
c
d
s
c
s
c
> 0;
ð9Þ
where the sign of the above expressio n fo llows from parts i and ii of
lemma 1. To prove the second part of the lemma, note that
dðu
m
u
s
Þ
dw
¼ α
2 h
m
pd
m
c
m
c
1 h
s
pd
s
c
s
c
¼
α
w
c
m
c
m
c
c
s
c
s
c
¼
α
w
1
1 c=c
m
1
1 c=c
s
< 0; ð10Þ
where the sign of the above expression derives from the fact that c
m
> c
s
,
or part ii of the corollary to lemma 1. QED
Thus, technological advance in the form of either a falling price for
purchased household inputs or rising real wages reduces the economic
gain from marriage. A fall in the price of purchased household inputs
leads to a substitution away from the use of labor in household produc-
tion toward the use of purchased household inputs. Single households
use laborsaving products the most intensively, so they realize the greatest
gain,thatis,d
m
=ðc
m
cÞ < d
s
=ðc
s
cÞ in (9). The assumption of strong
diminishing marginal utility for nonmarket goods (ζ < 0) is important
for the result that a drop in the price of purchased household inputs will
reduce the economic return to marriage. Suppose that ζ ¼ 0. Then prices
will have no impact on the utility differential between married and single
life, because d
m
=ðc
m
cÞ¼d
s
=ðc
s
cÞ by lemma 1. The presence of a fixed
cost is not important for obtaining the desired result, since the lemma still
holds when c ¼ 0. To take stock of the situation so far, a decline in the price
of household products will lead to a decrease in housework by proposi-
tion 1. It also causes a reduction in the economic return to marriage by
Greenwood and Guner246
proposition 2. Therefore, a decline in the price of purchased household
inputs has the potential for explaining observations 1 and 2 made in the
introduction.
As wages increase, the fixed cost for household maintenance matters
less. The fixed cost for household maintenance bites the most for single
households (i.e., c=c
m
< c=c
s
in [10]). Therefore, single households benefit
the most from a rise in wages. From (10) it is immediate that a change in
wages will have no impact in the absence of a fixed cost (c ¼ 0) on the
utility differential between married and single life. Also, note that this
result does not depend on the assumption of strong diminishing marginal
utility of n onmarket goods since the co rollary to le mma 1 holds even
when ζ ¼ 0. Now, recall from proposition 1 that an increase in wages will
cause housework to rise. Therefore, a rise in real wages alone cannot ac-
count for both observations 1 and 2.
4.
The Economic Value of Marriage
What is the economic value of married life? One way to measure this is
to compute the required income, or compensation, that is necessary to
make a single person as well off as a married one when there is no marital
bliss (b ¼ 0). The formula for the required compensation, expressed as a
fraction of the value of a single individuals time endowment, is surpris-
ingly simple and natural.
Lemma 2. The compensating differential between married and sin-
gle life is given by
ln ½Eðp; w; u
m
Þ=w¼ ln ½2
1ϕ
þð1 1=2
ϕ
Þc=w:
The result is very appealing and the underlying intuition straight-
forward. For expositional purposes, temporarily set c ¼ 0. On the one
hand, a married household has twice the time endowment of a single
one. On the other hand, a married household must provide consump-
tion to twice as many members. On net, owing to economies of scale in
household consumption, a married household realizes 2
1ϕ
(= 2=2
ϕ
)as
much consumption as a single one. Now, when c > 0, an adjustment
must be made for the presence of the fixed cost of household mainte-
nance. This reduces a singles consumption by c but a married onesby
only c=2
ϕ
, so that the difference is ð1 1=2
ϕ
Þc. Note that the income
needed to make a single person as well off as a married one is not a func-
tion of the price of purchased household inputs; one just needs to scale up
asingles income by the constant fraction 2
1ϕ
þð1 1=2
ϕ
Þc=w.Itisa
Marriage and Divorce since World War II 247
function of the wage rate, though. At higher wage rates the fixed cost
bites less. Finally, lemma 2 establishes that there is an economic in-
centive for marriage provided that there is some form of economies
of scale in consumption or production, that is, whenever either c > 0
or ϕ < 1.
It may seem a bit puzzling that a fall in price reduces the utility dif-
ferential between married and single life, u
m
u
s
, but has no impact on
the compensating differential between these two situations, ln ½2
1ϕ
þ
ð1 1=2
ϕ
Þc=w. This is true even when c ¼ 0; that is, the impact of price
on the difference in utility between married and single life is not due to
the presence of the fixed cost. Suppose that one makes the compensa-
tion outlined by lemma 2. Then, married and single households will use
laborsaving products in the same intensity, in the sense that d
m
=ðc
m
cÞ¼d
s
=ðc
s
cÞ.
5
After the required compensation is made, a change in
price will have no impact on the utility differential, u
m
u
s
, as can read-
ily be seen from (9). This suggests that the compensating differential is
not a perfect measure to use for tracking over time the impact of tech-
nological progress on the utility differential from marriage.
VI.
Quantitative Analysis
The households dynamic programming problemsa restatement. Given the
static nature of the households time allocation problem (P3), note that
the dynamic programming problems for single and married house-
holds, (P1) and (P2), can be rewritten as
W ¼ I ð 1; p; wÞþβ
Z
max ½V
ðb
Þ; W
dSðb
Þ
and
VðbÞ¼Ið2; p; wÞþb þ β
Z
max ½V
ðb
Þ; W
dMðb
jbÞ:
Here Iðz; p; wÞ gives the maximal level of momentary utility that a
zperson household can obtain, given that the price of purchased house-
hold inputs is p and that the wage rate is w. The fact that for a household
of a particular size, z, it is possible to calculate its current level of utility,
Iðz; p; wÞ, without regard to its marriage/divorce decision is very use-
ful. Given a sequence of prices and wages, fp
t
; w
t
g
t
, it possible to com-
pute from (P3) the associated sequence of momentary utilities for single
and married households, fIð1; p
t
; w
t
Þ; Ið2; p
t
; w
t
Þg
t
.
Greenwood and Guner248
A. Matching the Model with the Data
In order to simulate the model, numbers must be selected for the var-
ious parameters. Except for fiv e of the parameters, almost nothing is
known about appropriate values. Additionally, time series for prices
and wages need to be inputted into the simulation. Values for the mod-
els parameters either will be assigned on the basis of a priori informa-
tion or will be estimated.
1.
A Priori Information
Take the model period to be 1 year. In line with convention, set the sub-
jective discount factor at 0.96. The discount factor used in decision mak-
ing must reflect the individuals probability of survival, 1 δ. A persons
life expectancy is 1=δ. Thus, if (marriageable) life expectancy for an
adult is taken to be 47 years, then 1=δ ¼ 47. Therefore, set β ¼ 0:96
ð1 1=47Þ.Next,letϕ ¼ 0:77. This is in line wit h the Organization for
Economic Cooperation and Development's household equivalence scale
that treats the second adult in a family as consuming an additional
0.7 times th e amount of the first adult. Hence, the parameter ϕ solves
1=2
ϕ
¼ 1=ð1:0 þ 0 :7 Þ . A series for wages can be constructed from the
U.S. data. To do this, divide disposable income by hours worked to ob-
tain a measure of compensation per hour. The use of disposable income
should (partially) take into account the changes in taxes (and transfer
payments) that occurred over this time period. Between 1950 and 2000
compensation per hour worked rose 3.0 times. Thus, the analysis simply
presumes that wages rise at 100 ln ð3:0Þ=50 ¼ 2:2% per year. Finally,
the household production function is characterized by two parameters,
namely, κ and θ. These have been estimated by McGrattan, Rogerson, and
Wright (1997). Their numbers are used here.
6
2. Estimation
The rest of the parameters will be calib rated/estimated. First, a set of
data targets is picked. These targets summarize the data along five di-
mensions: the time allocations for both married and single households,
the fraction of the population married, the divorce rate, and the marriage
rate. Second, the parameter values in question are then chosen to maxi-
mize the models fit with respect to these data targets. Specifically, for this
section, define d
~
j
t
to be the jth data target for period t. Let λ be the vector
of parameters to be estimated. The model will yield a prediction for the
Marriage and Divorce since World War II 249
jth data target as a function of these parameters and time, denot ed by
d
j
t
¼ D
j
ðλ; tÞ. The estimation procedure solves
min
λ
X
5
j¼1
X
tT
I
j
t
ω
j
t
½d
~
j
t
D
j
ðλ; tÞ
2
=
X
tT
I
j
t

; ðP5Þ
where λ ðc; p
1950
; γ; α; ζ; μ
s
; σ
s
; μ
m
; σ
m
; ρÞ, I
j
t
f0; 1g is an indicator
function returning a value of one if there is an observationat date t, ω
j
t
gives
the weight assigned to the target, andT f1950; 1960; ...; 2000g. Unlike
the theory, the estimation does not restrict c 0orζ < 0; the data will de-
cide the magnitudes and signs of these parameters.
It is interesting to compare this strategy for picking parameter values
with the conventional one employed in business cycle analysis, discussed
in Cooley and Prescott (1995). Business cycle analysis models shortrun
fluctuations around a stationary mean. Hence, p arameter values are
typically picked so that the model matches up with some relevant
longrun averages from the data. In contrast, the current analysis fo-
cuses on longrun changes in a nonstationary world. The strong trends
observed in the data speak to the degree of curvature in tastes and tech-
nologies. Thus, the information contained in these trends should
be used to estimate parameter values. This is allowed by letting data
targets at different points in time enter i nto (P5). A discussion of the
10 parameters to be estimated and the 16 data targets used to identify
them will now follow.
Household technology parameterstime allocations. Obtaining a price
series for purchased household inputs is somewhat problematic. So, a
time path of the form p
t
¼ p
1950
e
γðt1950Þ
will be estimated here,
where γ is the rate of decline in the time price for purchased household
inputs and p
1950
is the initial price. The fixed cost for household main-
tenance, c, plays an important role in controlling the initial level of mar-
ket work expended by singles relative to married households. Nothing
is known about its value, so it will also have to be estimated. Thus, three
household technology parameters will be estimated: c, p
1950
, and γ.
To match the model up with the data on time allocations, note that
the fraction of time spent by a married household on market work, l
m
,is
given by l
m
¼ð2 h
m
Þ=2. Likewise, the fraction of time spent by a sin-
gle household working in the market is l
s
¼ 1 h
s
. Now, note that l
m
and l
s
can be written as functions of the parameters to be estimated,
namely, c, p
1950
, and γ. They are also functions of time, t, and the taste
parameters α and ζ.Thus,writel
m
t
¼ L
m
c; p
1950
; γ; α; ζ; tðÞand
l
s
t
¼ L
s
c; p
1950
; γ; α; ζ; tðÞ.
Greenwood and Guner250
Now, to operationalize the above in (P5), let d
~
1
t
l
~
m
t
, D
1
ðλ; tÞ
L
m
ðc; p
1950
; γ; α; ζ; tÞ, d
~
2
t
l
~
s
t
,andD
2
ðλ; tÞ L
s
ðc; p
1950
; γ; α; ζ; tÞ
for t ¼ 1950; 1960; ...; 1990. Also, set ω
1
t
=2andω
2
t
=2tobethefrac-
tions of married and single females in the time t population of women.
(Note that ω
1
t
þ ω
2
t
¼ 2, the number of data targets for the time alloca-
tions.) The theory developed suggests that the parameters c,p
1950
, and γ
will be important for determining the time paths for hours worked. As
a practical matter, it turns out that the time paths for hours worked largely
identify the magnitudes of c,p
1950
, and γ. Note that, as was mentioned
earlier, the matching parameters, μ
s
, σ
s
, μ
m
, σ
m
, and ρ , do not even enter
into the L
m
ðÞ and L
s
ðÞ functions.
Taste and matching parametersvital statistics. Th ere are seven taste
and matching parameters that need to be estimated, namely, α, ζ, μ
s
,
σ
s
, μ
m
, σ
m
,andρ.Theparameterα determines the weight of mark et
goods in the u tility function, and the parameter ζ controls the de gree
of concavity in the utility function for nonmarket goods. The more con-
cave this utility function is, the faster households will move away from
nonmarket goods toward market goods as income rises. Hence, this
parameter plays an important role in determining how the relative ben-
efits of married versus single life respond to technological progress. The
idea here is that information on the trend in vital statistics is important
for determining the value of ζ. The remaining six matching parameters
govern the noneconomic aspects of marriage. Again recall that L
m
ðÞ and
L
s
ðÞ are not functions of the matching parameters.
These seven parameters impinge heavily on the models predictions
concerning vital statistics. Here, the data are targeted along three dimen-
sions for two year s, 1950 and 2000: the fraction of the population mar-
ried, the divorce rate, and the marriage rate. So, let m
~
j
1950
and m
~
j
2000
denote t he data targets along the jth dimension for the years 1950 and
2000.Correspondingly,permitm
j
1950
¼ M
j
ðc; p
1950
; γ; α; ζ; μ
s
; σ
s
;
μ
m
; σ
m
; ρ; 1950Þ and m
j
2000
¼ M
j
ðc; p
1950
; α; ζ; μ
s
; σ
s
; μ
m
; σ
m
; ρ; 2000Þ
to represent the modelssteadystate output along the jth dimension
for the years 1950 and 2000. Hence, in (P5) set d
~
jþ2
t
m
~
j
t
, D
jþ2
ðλ; tÞ
M
j
ðc; p
1950
; γ; α; ζ ; μ
s
; σ
s
; μ
m
; σ
m
; ρ; tÞ, and ω
jþ2
t
¼ 1, for j =1,2,3
and t = 1950 and 2000. (Again, note that ω
3
t
þ ω
4
t
þ ω
5
t
¼ 3, the number
of data targets for the vital statistics.)
In summary, the parameter vector λ ðc; p
1950
; γ; α; ζ; μ
s
; σ
s
; μ
m
;
σ
m
; ρÞ is estimated so that the model matches the data on five dimen-
sions: the time allocations for married households, the time allocations
for single households, the fraction of the population married, the di-
vorce rate, and the marriage rate. This involves 16 observations from
Marriage and Divorce since World War II 251
the U.S. data. The estimation procedure employed is similar to one used
by Andolfatto and MacDonald (1998). Given the paucity of observations,
there is little point in adding an error structure to the estimation. Owing
to the heavy time costs of simulating the full model, the parameter α
was ar bitrarily restric ted to lie in a 21point discrete set A ¼f0:2; ...;
0:278; ...; 0:4g. The parameter values obtained from the above proce-
dure for matching the model with the data are presented in table 2. Before
proceeding, note from table 2 that the estimation procedure chooses
c > 0, ζ < 0, and γ > 0. Therefore, when the simple structure outlined
is estim ated, the data call for the presence of a fix ed cost in household
production, a utility function for nonmarket goods that is more concave
than the one for market goods, and a declining time price for purchased
household inputs; contrary to the theory, none of these features are im-
posed on the estimation procedure.
There is some indirect evidence, both crosssectional and timeseries,
that there might indeed be stronger diminishing marginal utility in non-
market goods visàvis market goods. Households with higher incomes
tend to allocate a larger share of their total food consumption for food
away from home. According to the U.S. Bureau of Labor Statistics
(2007, 7, table 1), in 2005 food away from home was about 35% of total
food consumption for households in the bottom income quintile,
whereas the same share for those at the top income quintile was 50%.
During the last century, as incomes rose, the share of food, housing, and
household operation in personal consumption expenditure fell. Such
spending constituted about 56% of total expenditure in 1929, whereas
it was about 40% of total expenditure in 2000 (from the U.S. National
Income and Product Accounts).
Table 2
Parameter Values
Category Parameter Values Criteria
Tastes β ¼ 0:960 ð1 δÞ, ϕ ¼ 0:766 A priori information
α ¼ 0:278, ζ ¼1:901 Estimatedvital statistics
Technology c ¼ 0:131 Estimatedhours data
θ ¼ 0:206, κ ¼ 0:189 A priori information
Life span 1=δ ¼ 47 A priori information
Shocks μ
s
¼4:252, σ
2
s
¼ 8:063 Estimatedvital statistics
μ
m
¼ 0:521, σ
2
m
¼ 0:680, ρ ¼ 0:896
Prices p
1950
¼ 9:959, γ ¼ 0:059 Estimatedhours data
p
t
¼ p
1950
e
γðt1950Þ
for t ¼ 1951; ...; 2000
Wages w
1950
¼ 1:00 Normalization
w
t
¼ w
1950
e
0:022ðt1950Þ
for t ¼ 1951; ...; 2000 A priori information
Greenwood and Guner252
B. Results
Visualize the economy in 1950. Wages are low and the price for pur-
chased household inputs is high, at leas t relative to 2000. Over time,
wag es grow and the price for purchased household inputs falls. The
time paths for wages and prices inputted into the analysis are shown
in figure 4. As can be seen, in the U.S. data, wages increase 3.0 times
over the time period in question. Prices are estimated to decline by a
factor of 20. This seems large, but it is merely the result of compounding
a 6.0% annual decline over a 50year period. Can these two facts help
to explain the decline in marriage and the rise in divorce over the last
50 years? This is the question asked here.
1.
Household Hours
The time path for household hours that arises from the model is shown
in figure 5. It mimics the U.S. data reasonably well. In particular, the
model matches very well the sharp increase in the fraction of time de-
voted to market work by married households. This is due to the declining
price for purchased household inputs. Purchased household inputs
and housework are substitutes in household production. As the price of
Fig. 4. Wages and prices, 19502000: model inputs
Marriage and Divorce since World War II 253
purchased household inputs declines, households substitute away from
using labor at home toward using goods. The tight fit should not be seen
as precluding the influence of other factors. For example, Albanesi and
Olivetti (2006) argue that advances in obstetric and pediatric medicine
and the introduction of new products such as infant formula al so pro-
moted labor force participation by married women.
The model has trouble mimicking the enigmatic Ushaped pattern for
single households; still, note the presence of an attenuated U. It does a
reasonable job of predicting the rise in participation from 1970 on. Ob-
serve that in 1950 married households devoted a smaller fraction of their
time to market work than single ones, in both the data and the model. In
the model this derives from the fixed cost of household maintenance.
This forces lowincome households to work more than highincome
ones. In the model the lowincome households are singles. As wages rise
this effect disappears. By 1990 in the United States, married households
worked more than single ones did. This is surprising since married
households are much more lik ely to have children. I n the model , they
work about the same. Perhaps in the real world more productive individ-
uals are also more desirable on the marriage market. Indeed, Cornwell
Fig. 5. Household hours, 195090: U.S. data and model
Greenwood and Guner254
and Rupert (1997) provide evidence that this is the case. Such a marriage
selection effect is missing in the model.
The estimation procedure picks a 6.0% annual rate of price decline, as
was mentioned. This looks reasonable. For instance, the Gordon quality
adjusted time price index for air conditioners, clothes dryers, dish-
washers, microwaves, refrigerators, televisions, videocassette recorders,
and washing machines fell at 10% a year over the postwar period. Al-
ternatively, one could take the price of kitchen and other hous ehold
appliances from the National I ncome and Product Accounts. This
price series declined, relative to wage growth, at about 1.5% a year since
1950. The 6% estimate obtained here is the midpoint of these two
numbers.
2.
Vital Statistics
Now, the model starts off from an initial steady state that resembles the
United States in 1950 and converges to a final one looking like the
United States in 2000. In 1950 about 81.6% of the female population
was married (out of nonwidows who were between the ages of 18 and
64). There were 10.6 divorces per 1,000 married females and 211 mar-
riages. According to Schoen (1983), marriages lasted about 30 years in
1950. In 2000 the picture was quite different. Only 62.5% of females were
married. The divorce rate had risen to 23 divorces by 1995, and the mar-
riage rate had declined to about 80 marriages. Finally, the average dura-
tion of marriages was about 2024 year s.
7
Table 3 shows the models
performance along these dimensions. Note that singles face a distribu-
tion with a low mean and a high variance, whereas married people face
a distribution that has a relatively high mean, a low variance, and a high
autocorrelation (see table 2). This ha s two effects. First, it encourages
singles to wait a while until a good match comes along. Second, it gen-
erates the long durations of marriages observed in the data.
Table 3
Initial and Final Steady States
1950 2000
Model Data Model Data
Fraction married .816 .816 .694 .625
Probability of divorce .011 .011 .024 .023
Probability of marriage .129 .211 .096 .082
Duration of marriages 31.36 29.63 22.47 2024
Marriage and Divorce since World War II 255
The fraction of the population that is married declines with the pas-
sage of time in the model. Figure 6 compares results obtained from the
model with the U.S. data. The model can explain 12 percentage points
of the observed 19percentagepoint decline in the number of married
females. This seems reasonable since other things went on in the world,
such as a rise in the number of people going to college, a decline in fer-
tility, and so forth. Observe that the utility differential between married
and single life declines over time.
8
This occurs for two reasons. First,
recall that the utility function for nonmarket goods is more concave
than the one for market goods. Thus, highincome households (married
couples) spend less on household inputs relative to market consumption
than lowincome household (singles). As a consequence, a fall in the price
of purchased household inputs has a bigger impact on singles visàvis
married couples. Second, as wages rise, the importance of the fixed cost
for household maintenance disappears. This is more important for single
households than for married ones. Finally, many couples choose to live
together but not marry. The framework can be thought of as model-
ing coup les living together. The fraction of females living with a male
fell by 16 percentage points between 1960 and 2000. From this angle,
Fig. 6. Decline in marriage, 19502000: U.S. data and model
Greenwood and Guner256
the model captures about 75% of the decline between 1950 and 2000.
Interestingly, the model seems to do well predicting the number of mar-
riagesforthefirsthalfofthesample and the number of cohabitations
for the later hal f.
Underlying the decline in the fraction of the U.S. population that is
married is a rise in the divorce rate and a decline in the rate of marriage.
This is true for the model too, as can be seen in figure 7. In the model,
divorces rise from 11 to 24 pe r 1, 000 married women. This compares
with 11 to 23 in the data. Marriages in the model fall from about 129
to 94 per 1,000 unmarried women. In the data they dropped from
141 to 69 or from 211 to 82, depending on the measure preferred. Thus,
by either measure, the drop in marriages in the model is a little anemic.
Again, it is not surprising that the model does not do well in this re-
gard. Some important factors have been left out, such as the rise in edu-
cation that surely must be associated with the delay in first marriages or
a narrowing in the gender gap that may have promoted female labor
forceparticipationandmadesinglelife a more desirable option for females.
Finally, in the data the duration of a marriage was 30 years in 1950. By
2000 this had declined to roughly 22 years. The model does well in this
Fig. 7. Rates of marriage and divorce, 195096: U.S. data and model
Marriage and Divorce since World War II 257
regard. It predicts that the duration of a marriage was 31 years in 1950
and 22 years in 2000.
VII.
19202000: A Proposed Extension
The effects of technological progress on the formation of households
were beginning to percolate before World War II. How are these effects
manifested in the data? Can the model be modified to address them?
A.
The Marriage Data
Figure 8 plots the proportion of the female population that was married
from 1880 to 2000. About 72% of the population was married in 1900, as
opposed to 62% in 2000. So, 10 percentage points fewer women were
married at the end of the twentieth century relative to the beginning.
Observe that the number of marriages shows a humpshaped pattern
roughly coinciding wit h the baby boom years. This pattern is not as
dramatic as it seems at first glance, though. The population was much
younger at the turn of the last century than it is today. Women aged 1824
made up 28% of the population in 1900. Now they account for 15%. Young
women are much less likely to be marrie d than older ones. Figure 8
also shows the fraction of the female population that are married after
Fig. 8. Marriage, 18802000
Greenwood and Guner258
a correction is made for the shift in the age distribution. First, note that
many more females were married at the beginning of the century than at
the end, about 17 percentage points more. Second, the hump is still there,
but it is much less pronounced. What can account for this humpshaped
pattern in marriage? Specifically, why did the number of marriages rise
between 1940 and 1960 and subsequently decline?
B.
Living Arrangements of Young Adults
At the beginning of the twentieth century the vast majority of never
married young females (close to 80%) lived as dependents with their
parents. A substantial fraction lived in households as nonrelatives, for
example, boarders, servants, and so forth. Almost none lived in their
own household, however. The fraction of young standalone house-
holds made up by singles has become much more prevalent over time.
It has risen from close to zero at the turn of the last century to about
50% today, as figure 9 illustrates. Additionally, figure 9 plots the pro-
portion of young households made up of married couples. As can be
seen, it fell from nearly 100% at the turn of the last century to less than
50% today. Interestingly, this plot shows a monotonic decline from
roughly 1920 on; the hump has disappeared.
Fig. 9. Living arrangements for young women, 18802000
Marriage and Divorce since World War II 259
C. Returning to the Hypothesis
The idea here is that technological progress in the household sector
made it feasible to establish smaller and smaller households. In the ini-
tial st ages of development, techno logical advance made it easier f or a
young adult to leave his or her parents home and marry. As household
technology progressed further, it became viable for young adults to leave
home and remain single. Therefore, the move by young adults from large
to twoperson households coincided with an increase in marriages
whereas the subsequent shift toward oneperson households was asso-
ciated with a decline. This hypothesis is consistent with the decline in the
fraction of total young households made up of married ones that was
shown in figure 9.
1.
Altering the Setup
To gauge whether or not this hypothesis has promise, consider the fol-
lowing simple extension of the model. Let there now be three types of
individuals: singles living at h ome with their families (dubbed young
adults), singles living in their own homes, and married couples living
in their own households. Suppose that a young adult living with his
family receives a momentary utility of H x . Here H gives the economic
benefit from living at home, as a function of the underlying state of the
economy (w, p). The variable x represents the psychic disutility from liv-
ing at home (vs. alone), so to speak. Each single starts adulthood living at
home with his or her parents and sibling. Assume that a young adult first
leaves home single and then looks for a mate. In particular, he or she exits
the family nest with probability ε. This probability is a choice variable,
whichisdependentontheamountofeffortthattheyoungsterin-
vests in leaving home. Let the convex cost function for leaving home,
C : ½0; 1 R
þ
, be specified by
CðεÞ¼ι
ε
1þχ
1 þ χ
for χ > 0:
Once departed, the youngster can never return. A lso, presume that a
family realizes no benefit (or incurs a cost) from a child staying at home.
The rest of the setup remains the same as before. The analysis will focus
on steady states.
Greenwood and Guner260
Let Y be the expected lifetime u tility for a young adult who is cur-
rently living at home. His dynamic programming problem is given
by
Y ¼ H x þ β max
0ε1
ε
Z
max ½VðbÞ; W dSðbÞþð1 εÞY CðεÞ
:
The solution for ε is given by
ε ¼
R
max ½VðbÞ; WdSðbÞY
ι
1=χ
for 0
Z
max ½VðbÞ; WdSðbÞYι:
As can be seen, a youngster will be more diligent about leaving home
when the gains from entering the singles market,
R
max ½VðbÞ; WdSðbÞ,
are high relative to the benefits of staying at home, Y. Now, consider
an increase in wages or a fall in prices. These will lead to reductions in
the number of young adults living at home, as long as the benefits of in-
dependent single life rise more than the benefits of a dependent one, that
is, as long as
R
max ½VðbÞ; WdSðbÞ=w > Y=w or
R
max ½VðbÞ;
WdSðbÞ=p < Y=p. The considerations ensuring this parallel those
outlined in Section V.
Note that problems (P1) and (P2) remain the same as before, since the
decision to leave home is irreversible and because a married couple real-
izes no utility from a child living at home. In a steady state the equation
specifying the type distribution for marriages will appear as
MðbÞ¼ð1 δÞ
ZZ
M½;b
dMð b
~
jb
1
ÞdMðb
1
Þ
þ½ð1 δÞs þð1 δÞεy þ δε
Z
M½;b
dSðb
~
Þ;
where the number of young adults living at home with their parents, y,is
given by
y ¼
δð1 εÞ
1 ð1 δÞð1 εÞ
;
and
Z
dMðbÞþs þ y ¼ 1
(cf. [5]). Therefore, a huge virtue of this setup is that it involves little mod-
ification to the original formulation.
Marriage and Divorce since World War II 261
2. An Example
Does the above setup have promise for extending the earlier analysis to
the preWorld War II period? To address this question, the models po-
tential will be demonstrated using a simple example. The example will
focus on three years, to wit, 1920, 1950, and 2000. For each year the models
steady state will be computed . The output from the model will then
be compared with the styl ized facts discussed in Sections VII.A and
B. It should be emphasized that given the simplicity of the setup, the
example is intended only as an illustration; it should not be viewed
as a serious datafitting exercise.
For the taste and technological parameters, take the values presented
in table 2 with two changes. Presumably the price for purchased house-
hold inputs fell faster earlier in the last century than later on. So allow
the price to fall at the constant rate γ
1920
prior to 1950. Additionally, the
fixed cost for household formation will be allowed to differ for this sub-
period as well. Denote this by c
1920
. The above setup changes the pool
of singles that are available on the marriage market. So, new matching
parameters will be selected. These values will apply for the whole
19202000 period. Something must be specified for the economic benefit
that a young adult derives from staying at home with his parents, Hðw; pÞ.
Simply suppose that each family has two kids and set Hðw; pÞ¼
Ið4; p; wÞ. That is, each period a young adult who stays at home realizes
the maximal l evel of momentary utility that would arise in a household
with four wage earners. (One could just as easily set Hðw; pÞ¼ϑIð4; p;
wÞ for some ϑ ð0; 1Þ. T he essential requirement is that the economic
benefit of l iving in a large hous ehold should decline over time relative
to a small one.) Given the primitive nature of the example, the param-
eter values are selected so that the models steady state s displ ay some
features of interest, discussed below. The parameter values selected are
presented in table 4.
In the model, 63.8% of single women work in 1920, the same number
as in the data for women between the ages of 18 and 64 (see table 5).
Table 4
New Parameter Values: Example
Household production c
1920
¼ 0:161, γ
1920
¼ 0:165
Shocks μ
s
¼3:75, σ
2
s
¼ 8
μ
m
¼ 0:145, σ
2
m
¼ 0:28, ρ ¼ 0:59
Utility of living at home Hðw; pÞ¼Ið4; p; wÞ
x ¼ 2:051
Utility cost of leaving home ι ¼ 115:27, χ ¼ 1:083
Greenwood and Guner262
Likewise, only 7.8% of married women work in 1920, again the same as
is observed in the data. By construction, the model still generates the
hoursworked predictions shown in figure 5 for the period 195090.
This transpires because the hoursworked decisions are functions solely
of the taste and technology parameters, and these have not been changed
for the 19502000 period. Table 6 presents the results for some vital sta-
tistics. The statistics for the U.S. data apply to women in the 1864 age
group (as in table 3). The numbers have also been adjusted for the shift
in U.S. age distribution, which was discussed earlier. First, as can be seen,
the model replicates quite nicely the stylized facts for the fraction of fe-
males who are married. In particular, the model duplicates the hump
shaped pattern displayed in the data. An improvement in fitting the
numbers for 2000 can be obtained at the sacrifice of a diminution in the
lefthand side of the hump. Second, it also does a reasonable job of pre-
dicting the decline in the proportion of single females who live at home
with their parents. Third, analogously, it mimics well the rise in the frac-
tion of single females who live alone. Fourth, the number of adults living
in a household declined monotonically over the course of the last century,
as ta ble 6 sh ows. This is true for the model as well. The model cannot
match the steepness of this decline. One reason might be that fertility de-
clined in the United States over this time period, and the population aged
significantly. The elderly are much more likely to live alone now, relative
to the past. The model, of course, assumes that each woman always gives
birth t o two children. All in all, it looks as though an extension of the
framework that models the decision of a young adult to leave home
Table 6
Household Living Arrangements
1920 1950 2000
Model Data Model Data Model Data
Married: m .796 .791 .819 .819 .680 .616
Single, living at home: y .185 .185 .125 .125 .109 .109
Single, living alone: s .019 .024 .056 .056 .212 .275
Household size: number of adults 2.40 2.55 2.15 2.14 1.81 1.65
Table 5
Participation Rates, 1920
Model Data
Married .078 .078
Single .638 .638
Marriage and Divorce since World War II 263
has promise for explaining the trends in vital statistics that are observed
in the U.S. data.
3.
Discussion
The proposed extension of the benchmark model is minimalist, to say
the least. It is easy to identify areas of the analysis that warrant further
work. At the heart of the above extension is a young adults decision to
leave home. Perhaps one could allow for a young adult to search for a
mate while at home. Three options would then arise: stay at home, leave
home married, and leave home single. Doing this will be important for
matching the rates of marriage that are observed in the data. In the earlier
part of the last century most females got engaged before they left home.
Therefore, the model cannot hope to match the observed rates of mar-
riage at early dates if marriageability is restricted to the small pool of
single females living alone. Additionally, should searching for a mate
while living i n your parents home be as efficient as searching f or one
when you live alone? Modeling the utility that a young adult receives while
at home is another area in which the framework could be improved. Do
transfers flow from young adults to parents or vice versa? The answer to
this will depend on how parents care about their kids, how children feel
about their parents, and their mode of interaction.
The economic forces that reduce the relative benefit of single versus
married life may also have affected other living arrangements, such
as the incentives of the elderly to live with their kids. Between 1970
and 1990 the fraction of widows living alone rose from 52.1% to 64.2%.
Bethenc ourt and RiosRull (2009) argue that the rise in the relative in-
come of elderly widows can account for a significant part of the rise in
the number of e lderly widows living alone between 1970 and 1990. In
a similar vein, Schoellman and Tertilt (2007) argue that a substantial pro-
portion of the decline in household size is due to an increased demand for
privacy, made possible by rising living standards.
VIII.
Some CrossCountry Evidence on Household Size
The above theory suggests that as the relative price of purchased house-
hold inputs declines, so should the number of adults living in a house-
hold. The relationship between household size and price is displayed in
the upper panel of figure 10 for a small sample of Western countries for
the year 2001. As can be seen, there is a positive association between these
two variables. Of course, other things may affect household size in a
Greenwood and Guner264
country. To take into account such factors, a linear regression of the fol-
lowing form is estimated:
SIZE ¼ CONSTANTþ β PRICEþγ CONTROLSþε;
with ε Nð0; σÞ, where CONTROLS represents a vector of control vari-
ables. A list of potential control variables might include GDP per cap-
ita, the gender gap, the extent of urbanization, the amount of product
market regulation, and the religiosity of a population. The empirical anal-
ysis is in the spirit of Cavalcanti and Tavares (2008) and Algan and Cahuc
(2007), who examined, using a panel of countries, the impact of appliance
prices on female labor supply and younger and o lder (nonprimeage)
wor kers, respectively. Theory suggests that β should be positive. The
size of this coefficient is also of interest because it indicates the power
of the relative price effect.
The results of the analysis are presented in table 7. They should be
interpreted with the utmost caution because the sample size is so small.
Focus attention on regression 5. All the variables are statistically signifi-
cant and enter in with the expected sign. The price effect in the regression
is highly significant. One would expect, as per capita GDP rises, that
Fig. 10. Crosscountry relationship between household size and the relative price of
appliances, 2001.
Marriage and Divorce since World War II 265
household sizethe number of adults between ages 18 and 64declines.
Females will be less inclined to marry and more inclined to divorce, the
higher their wage rate relative to males, since this makes it more likely
that they can live an independent life. Indeed, in the regression, house-
hold size is negatively related t o the gender gap, defined as the ratio
of female to male wages. Religious societies may frown on young adults
living by themselves or couples getting divorced. Household size is pos-
itively associated with religiosity, as measured by the fraction of the
population that view themselves as religious. Other v ariables such as
the fraction of the population that lives in urban areas (not shown), per-
haps a measure of less traditional attitudes, or the degree of product mar-
ket regulation, which increases the cost of living, have the expected signs
but are less significant (when GPD per capita and the gender gap are in-
cluded in the regression). Adding them changes only marginally the coef-
ficient on the price effect or its significance. A robustness check found that
controlling for the age structure of the population does not seem to mat-
ter much either. Additionally, the basic results continue to hold in a larger
sample that includes excommunist countries, such as Bulgaria, the Czech
Republic, Estonia, and so forth. The lower panel in figure 10 shows the
relationship between price and household size after controlling for the
factors included in regression 5.
What about the economic significance of the size of the coefficient on
price in the regression? To gauge this, compare Finland, which had the
Table 7
CrossCountry Regression Analysis
Regression
Independent Variable 1 2 3 4 5
Constant 1.907
***
1.699 .878 2.110
***
1.092
***
(.545) (.466) (.513) (.434) (.331)
Relative price .0263
***
.0275
***
.0212
***
.0267
***
.0244
***
(.0047) (.0043) (.0040) (.0037) (.0033)
GDP per capita .000015
***
.000013
**
(4.58e06) (4.13e0.6)
Gender gap .637
**
.404
**
(.233) (.135)
Product market regulation .102
*
(.049)
Religion .825
***
.867
***
.657
***
.759
***
.722
***
(.165) (.109) (.189) (.196) (.119)
Observations 14 14 14 14 13
Adjusted R
2
.700 .856 .781 .772 .897
Note: Standard errors reflect EickerWhite correction for heteroscedasticity.
*
Significant at 10%.
**
Significant at 5%.
***
Significant at 1%.
Greenwood and Guner266
lowest relative price level of 104.8, with Ireland, which had the highest
relative price level of 122.01. The relative price difference is associated
with about 0.44 member per household (about 100% of the obs erved
difference, from 1.424 for Finland to 1.879 for Ireland). This price effect
is quantitatively powerful. An increase in per capita GDP from $17,440
(Greece with a household size of 1.86) to $34,320 (the United States with
a household size of 1.65) leads to a drop in household size of 0.22 mem-
ber (again almost all of the difference between the two countries). By
comparison, the gender gap has a much weaker impact. Suppose that
the gender gap shrinks from 0.4 (Ireland, the widest) to 0.7 (Denmark,
the narrowest). Household size falls by 0.12 member, which represents
25% of the difference. Thus, the forces stressed in the paper appear to
have a strong impact on household size.
IX.
Conclusions
The fraction of adult females who are married has dropped by roughly
20 percentage points since World War II. Females now spend a much
smaller part of their adult life married than 50 years ago. Associated
with this has been a rise in the divorce rate and a decline in the rate of
marriage. At the same time, hours worked by married households rose
considerably. This was driven by a large increase in labor force participa-
tion by married females.
An explanation of these facts is offered here. The story told focuses
on technological progress in both the hou sehold and market sectors.
The idea is that investmentspecific technological progress in the house-
hold sector reduced the need to use labor at home. This simultaneously
allowed women to enter the labor force and eroded the economic incen-
tives for marriage. The analysis blends together a search model of mar-
riage and divorce with a model of household production. The economic
incentives for marriage derive from economies of scale in household pro-
duction. These are whittled away over time for two reasons. First, rising
wages make it easier to meet or exceed the fixed cost for household main-
tenance. This reduces the ne ed to marry to make ends meet. Second, a
falling price for laborsaving household inputs has a bigger impact on sin-
gle visàvis married households, since the former devote a larger share
of their spending to these products as a result of a high rate of diminish-
ing marginal utility for nonmarket consumption. Thes e two effects in-
crease the (relative) value of single life.
So, where can the analysis go from here? Technological progress in
thehomeandmarketmayaffectthepattern of matching in society.
Marriage and Divorce since World War II 267
There is some evidence that the degree of assortative mating in the United
States has increased since 1940.
9
Extensions of the model may be able to
capture this. Suppose that individuals differ in their labor market pro-
ductivities. Assume that married males devote all their time to market
work whereas married females split their time between market work
and household work. Now, when they choose a potential mate, their
earnings in the labor market will be a consideration. This will matter less
at early stages of economic development, since married women will do
little market work because of the large amount of time spent in household
production. As women start to work more in the market, owing to tech-
nological progress, it will begin to matter more. As an economy advances
and the benefits from economies of scale in household consumption dimin-
ish, earnings potential along with marital bliss will become more im-
portant criteria when choosing a mate. The degree of assortative mating
will increase. Additionally, such an analysis would likely imply that
the drop in t he marriage rate should be biggest for those individuals
in lowerincome groups, since the relative benefits from marriage will
fall the most for them. Indeed, there is some evidence suggesting that this
has been the case.
10
Appendix
A.
Proofs
As a prelude to the proofs of the lemmas and propositions, combine (7)
and (8) to obtain
d ¼
ð1 θÞp
θ
1=ðκ1Þ
h RðpÞh: ðA1Þ
Using this in (6) then gives
c c ¼ w

z
c
w
h
wpd ¼ w

z
c
w
h
wpRðpÞh: ðA2Þ
Finally, by substituting (A1) and (A2) into (8), a single equation can be
obtained in one unknown, namely h:
α½θRðpÞ
κ
þð1 θÞ
1ζ=κ
h
1ζ
¼ð1 αÞð1 θÞz
ϕζ

z
c
w
h pRðpÞh
:
ðA3Þ
Greenwood and Guner268
The solution is portrayed in figure A1. It is easy to deduce that the left
hand side of (A3) is increasing in h since ζ < 0. It is trivial to see that the
righthand side is decreasing in h.
Proof of proposition 1. On part i, observe that both RðpÞ ¼ f½ð1
θÞ=θpg
1=ðκ1Þ
and pRðpÞ are decreasing in p since 0 < κ < 1. Therefore,
the righthand side of (A3) falls with a drop in p,aspRðpÞ is increasing
in p. Thus, the RHS curve in figure A1 will shift down when p declines.
The lefthand side increases w ith a reduction in p because RðpÞ
κ
is de-
creasing in p. Hence, the LHS curve shifts up. As a consequence, h unam-
biguously drops. For parts ii and iii, note that w and c enter into (A3) only
in the form c=w. It is trivial to see that the righthand side of (A3) is de-
creasing in c=w, whereas the lefthand side is not a function of c=w. There-
fore, an increase in c=w wi ll cau se h to fall. The des ired results follow
immediately. QED
What is the relationship between the size of a household, on the one
hand, and the amount of time allocated to housework and spending on
goods, on the other hand? One would expect housework, h,torise
when size, z, increases because the total endowment of time has risen.
This is true. A more interesting question is whether or not housework
rises by a factor more or less than the proportionate increase in household
Fig. A1. Determination of h
Marriage and Divorce since World War II 269
size. On the one hand, given that the utility function for nonmarket goods
is more concave than the one for market goods, the household has a pref-
erence for diverting extra resources into market consumption. This sug-
gests that housework will increase le ss than proporti onately with size.
On the other hand, at higher levels of income the fixed cost for household
maintenance will matter less. This suggests that housework will rise
more than proportionately with size. While the result turns out to be am-
biguous, a useful upper bound on the response of housework to house-
hold size can be derived. This is presented in lemma 3, which is an
important step toward proving proposition 2. With this upper bound,
it can be shown that married households spend less than single house-
holds do on the inputs into household production, d and h, at least rela-
tive to market consumption, c c.
Lemma 3. A rise in z by a factor of λ > 1 leads to an increase in h by
a factor strictly less than ρ ¼ðλz c=wÞ=ðz c=wÞ.Whenζ ¼ 0 (ln utility
for nonmarket goods), a magnification in z by a factor of λ > 1willcauseh
to expand by exactly a factor of ρ.
Proof. Rewrite equation (A3) as
α½θRðpÞ
κ
þð1 θÞ
1ζ=κ
h
ζ
h þð1 αÞð1 θÞ½1 þ pRðpÞz
ϕζ
h ¼
ð1 αÞð1 θÞz
ϕζ
ðz c=wÞ:
If z increases by a factor λ > 1, then z c=w rises by the fact or ρ
ðλz c=wÞ=ðz c=wÞ > λ. Now, the righthand side rises by the factor
λ
ϕζ
ρ. Observe that if h rises by the factor ρ, then the lefthand side will
increase by more than the factor λ
ϕζ
ρ, because ρ
ζ
> λ
ϕζ
when ζ < 0
and 0 < ϕ < 1. Therefore, to restore equality between the lefthand and
righthand sides of the above equation, h must rise by less than the fac-
tor ρ. The first part of the lemma has been established. Finally, suppose
that ζ ¼ 0. In this case, (A3) reduces to
h ¼
ð1 αÞð1 θÞð z c=wÞ
α½θRðpÞ
κ
þð1 θÞ þ ð1 αÞð1 θÞ½ 1 þ pRðpÞ
: ðA4Þ
The second part of the lemma follows immediately. QED
In line with the intuition presented above on the relationship be-
tween household size and allocations, suppose that c ¼ 0. In this case,
ρ ¼ λ. Thus, larger households will devote proportionately less of their
time to hou sework than smaller ones, since an increase in household
size by a factor λ > 1 will lead to a rise in h by a factor less than ρ ¼ λ. Next,
suppose that ζ ¼ 0andc > 0, so that both market goods and nonmarket
Greenwood and Guner270
goods have ln utility. If z increases by a factor of λ,thenh will rise by exactly
the factor ðλz c=wÞ=ðz c=wÞ > λ. Now, larger households spend pro-
portionately more of their time on housework relative to smaller ones.
This lemma will now be used in the proof of lemma 1.
Proof of lemma 1. First, result iii is immediate from lemma 3. Second,
it is easy to see that result ii is implied by equation (A1) and result iii.
By using results ii and iii, in conjunction with equation (A2), one can
obtain result i. Finally, the situation for ζ ¼ 0 is readily handled by
using the closedform solution (A4). QED
Proof of corollary. From lemma 1, note that when ζ 0, it transpires
that ðc
m
cÞ 2ðc
s
cÞ, since ð2 c=wÞ=ð1 c=wÞ 2. Thus, ðc
m
cÞ=
2
ϕ
2
1ϕ
ðc
s
cÞ > c
s
c. Part ii of the corollary follows trivially. QED
B.
Data
Figure 1. The marital statu s of the population is reported in the U.S.
Census Bureau publications Marital S tatus and Living Arrangements
(March 1950 to March 1998) and Americas Families and Living Arrange-
ments (March 1999 to March 2000). The fraction of time spent married is
calculated as follows: First, data on life expectancy, e, and the fractions
of total life spent as never married, n, married, m, and divorced, d,are
collected from Schoen (1983) and Schoen and Standish (2001). These
data cover each year between 1950 and 1980 and the years 1983, 1988,
and 1995. Second, on the basis of these numbers, the figures presented
are then calculated as
e m
e n 18 þ e m þ e d
:
Figure 2. The divorce and marriage rat es are contain ed in Clarke
(1995a, 1995b). A caveat is in order. Whereas data are available on
the number of unmarried women by age group, they are not available
for marriages by age group. Hence, the marriage rate for a particular age
group is computed as the total number of marriages divided by the total
number of unmarried women in the given age group. Therefore, the mar-
riage rates are somewhat sensitive to the particular age group used as the
base for the calculations. Divorce and marriage statistics (which primar-
ily come from the National Center for Health Statistics) are not available
after 1996.
Figures 3 and 5. Simple tabulations are computed on the basis of U.S.
Census data extracted from IPUMSUSA (Integrated Public Use Micro-
data Series, Minnesota Population Center, University of Minnesota). To
Marriage and Divorce since World War II 271
calculate the fraction of time spent working in the United States for the
period 195090, assume that there are 112 nonsleeping hours in a week.
Following t he footsteps o f McGra ttan and Rogerson (1998), weekly
hours per married and single households can be calculated using U.S.
Census data. For each decennial year between 1950 and 1990, the census
provides hours per week in the following intervals: 114, 1529, 3034,
3539, 40, 4148, 4959, and more than 60 hours. Let E
i
denote the num-
ber of people who report hours in a particular interval i, E
R
represent
the total number of people reporting hours, E stand for the total num-
ber of people employed, and N be the total population. Then, the fraction
of total nonsleeping time allocated to the market is calculated as
ð7:5E
114
þ 22E
1529
þ 32E
3034
þ 37E
3539
þ 40E
40
þ 44:5E
4148
þ 42E
4959
þ 62:5E
60þ
Þ
1
E
R
E
N
1
112
:
This fraction is computed by marital status for all males and females be-
tween ages 24 and 54. The fractions of total household time allocated to
the market by married households, l
~
m
, and by single households, l
~
s
,are
then calculated as the averages across male and female hours. Thus, an
observation for l
~
m
t
and l
~
s
t
is obtained for each decade t between 1950 and
1990, inclusive.
Figure 4, wages. The series for disposable p ersonal income from t he
National Income and Product Accounts is taken and divided through
by hours worked by fulltime and parttime employees, both avail able
from the Bureau of Economic Analysis, U.S. Department of Commerce.
Figure 6. The fraction of females living with a male is defined to be
the fraction of females who are married plus the fraction of females
who are unmarried living with a male. The size of this latter group is
tabulated using the Census Bureaus posslq household variable
persons of the opposite sex sharing living quarters. This variable unfor-
tunately also includes people who are not partners. Still, it probably is a
good proxy for the number of cohabitations. Note that the number of
unmarried couples living together before 1960 would have been small
and can be safely ignored.
Figures 8 and 9. The facts displayed in these graphs are again based
on tabulations from Census data downloaded from IPUMSUSA. In fig-
ure 8 the adjustment for the shift in the age distribution is done using
the typical method employed by demographers. Let p denote the total
femal e population at a point in time. Suppose that this population is
made up of I age groups. Define p
i
to represent the number of women
Greenwood and Guner272
in the ith age group and allow m
i
to proxy for the number of these women
who are married. The fraction of married females in the total population
is then given by
f ¼
X
I
i¼1
m
i
p
i
p
i
p
:
Hence, f depends both on the age composition of the population (or the
p
i
=p terms) and on the fraction of each age group who are married (or the
m
i
=p
i
terms). Now, for any year t, define an ageadjusted measure by
f
^
t
¼
X
I
i1
m
i;t
p
i;t
p
i;2000
p
2000
:
Thus, f
^
t
calcu lates the fraction of women who would be married if t he
age composition of 2000 was in effect at time t. In figure 9 an independent
single female is defined to be a nevermarried woman who is either the
head of a household or the friend or partner of a householder. The curve
labeled single, on own graphs this group relative to all single females.
The curve marked married shows the number of married females rela-
tive to the number of married plus independent single ones. The plots in
figure 9 are restricted to women in the 1830 age group.
Table 5, l abor force participation rate for 1920. Prior to 1940 it is not
possible to obtain hoursworked data for married and single females.
Thus, for 1920 labor force participation rates are used instead. This is
done by heroically assuming that the workweek is fixed at 40 hours and
that there are 112 nonsleeping hours in a week. It is also assumed that all
males work a 40hour week. Denote the rates of participation for married
and single females by f
m
1920
and f
s
1920
.Then,forthemodel,f
m
1920
and f
s
1920
can
be obtained from hours worked, h
m
1920
and h
s
1920
, by using the formulas
2 h
m
1920
2
¼
40 þ 40 f
m
1920
2 112
and 1 h
s
1920
¼
40 þ 40 f
s
1920
2 112
:
Tab le 6. The numbers in the table for the U.S. data are derived as
follows: First, the counts for the fractions of females who are married,
m, are taken from the data displayed in figure 8. Second, in the model
only nevermarried females live at home. Suppose that this is true in the
data as well. The number of nevermarried females at home is given by
the formula for y. Third, s ¼ 1
R
dMðbÞy. All numbers in the table
refer to women in the 1864 age group and have been adjusted to con-
trol for shifts in the age distribution of the population (in the manner
discussed above). Four th, to calculate average household size for the
Marriage and Divorce since World War II 273
U.S. data, simply take the size of the 1864 population and divide it
through by t he number of independent households. The same thing
can be done for the model by using the formula 2=½2s þ
R
dMðbÞ.
Table 7. Household size is the population between the a ges of 18
and 64 per household. For the United States, the data come from the
2000 Census. For all other countries EUROSTAT data on population
and social conditions for the year 2001 are used. For the United States
the relative price of household appliances is defined to be the price index
for kitchen and other ho usehold appliances relative to the one for per-
sonal consumption expenditures (taken from the National Income and
Product Accounts). For the rest, EUROSTATs Harmonized Indices of
Consumer Prices (HICP) is used to calculate the price index for house-
hold appliances (cp053) relative to one for all itemsHICP (cp00).
GDP per capita (in purchasing power parity U.S. dollars) and the gender
gap are the 2001 values given in the Human Development Report (2003).
The product market regulation index, with higher values indicating
more regulation, is for the year 1998. The source is Conway, Janod, and
Nicoletti (2005). Religion represents the fraction of peo ple who classify
themselves as religious in the 2000 World Values Survey.
Endnotes
Daron Acemoglu, Alvaro Aguirre, Kei Muraki, Claudia Olivetti, and Juan Sanchez are
thanked for helpful comments. Financial support from the M inisterio de Educacion y
Ciencia (grant SEJ200765169) and the National Science Foundation is gratefully acknowl-
edged. Greenwood and Guner (2008) present additional material on the theory developed,
supplement the simulation with sensitivity analysis, and provide extra discussion of the
crosscountry evidence.
1. Data sources, and issues regarding the facts and matching them with the model to be
developed, are detailed in the appendix.
2. The impact of technological progress on household formation was addressed some
time ago in a classic and prescient book by Ogburn and Nimkoff (1955). The book ana-
lyzes the impact of technological progress on family size, marriage and divorce, and fe-
male labor force participation, among other things.
3. Ogburn and Nimkoff (1955, 4041) quote Godeys Ladys Book in 1831 as writing that
No sensible man ever thought a beautiful wife was worth as much as one that could
make good pudding or in 1832 as stating that Among our industrious forefathers it
was a fixed maxim that a young lady should never be permitted to marry until she had
spun for herself a set of body, bed and table linen. From this custom all unmarried women
are called spinsters in legal proceedings.
4. Note that when a single agent dies, he is replaced by another single agent. This ex-
plains why there is no term reflecting the probability of dying multiplying s
1
in the for-
mula for MðbÞ.
5. The proof of lemma 2 contained in Greenwood and Guner (2008) makes this clear.
6. The important parameter is the elasticity of substitution between goods and time in
production, 1=ð1 κÞ. Chang and Schorfheide (2003) also find that goods and time are
substitutes in the household production f unction. Their estimate is not far off from
McGrattan et al.s (1997).
Greenwood and Guner274
7. There are not any recent estimates for the duration of marriages. Schoen and Standish
(2001) estimate the duration of marriages to be about 24 years in 1995, whereas Espenshade
(1985) estimates it to be 22.5 years for white females and 14.6 for black females over the
period 197580. The steadystate duration of marriages in the model is given by
d
m
¼
1
1 π
mm
ð1 δÞ
;
where π
mm
is the probability of a married agent remaining married next period.
8. In line with the discussion surrounding lemma 2, the compensating differential
needed to make a single as well off as a married person falls only from 20.7% to
17.7%. This small decline is due to the fact that the fixed cost, c, is only a small fraction
of the value of a singles time endowment, w. Choo and Siow (2006) estimate a nontrans-
ferable utility model of the U.S. marriage market. Their estimates show that the gains to
marriage for young adults fell sharply between 1971 and 1981.
9. See Lam (1997) for some facts on the correlation of income levels across partners and
Schwartz and Mare (2005) for education.
10. Wallace (2000) finds that the decline in the marriage rate is inversely related to the
level of education.
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