Brit. J. soc. Med.
(1952),
6,226-244
COHORT ANALYSIS OF FERTILITY IN ENGLAND
AND WALES, BY
1939-50
WALLIS TAYLOR o...
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Brit. J. soc. Med.
(1952),
6,226-244
COHORT ANALYSIS OF FERTILITY IN ENGLAND
AND WALES, BY
1939-50
WALLIS TAYLOR of Medical
Department
Statistics,
and Central
of Birmingham,
University
Is the elimination
(1) Introduction The
to social
relevance
... in the changes little amplifica
of
medicine
as
to interpret a view rate with
of hospital
and on
depends
the
Though in
e.g.
ancillary current the is of
issue
for
demand
the
to
relevance
special
if we reflect upon services
welfare Since mean
of
the National
before,
and
during,
a falling rate birth a decline in primiparae
interpret
medical costing steadiness the
of
rates
accurate
made
services.
the
under
different
Dispute
was
the
and
the
assumptions then about
1939-45
effect
of
war,
This
than
in
about method. Since 1939, the rapid fluctuation of the rates (Fig. 1) has made prognostication without
fruitless
recourse
The need for new methods paper
out
sets
one
such,
to more
refined
cohort
new
in this context although previously employed in medical research (vide infra). This method is then used to analyse recent fertility in England and Wales
and
In one
to estimate of
the very
its significance few
recent
for replacement. analyses
applicable to England and Wales, asks the following questions:
of
Hajnal
be
current
of of
reversal
immediate
the
to demon
adequate
falling fertility and its immediate
age-composition
the population.
the pre-war
post-war work earlier
trend during has en years on the social
rates
to a reason in part adumbrated of composite The credentials
is due remarks.
of fertility
indices
analysis.
method,
idea
earlier
tion
is imperative; and this the
may
the idea that couraged determine has little relevance which fertility agencies to present that forecasts and conditions, suggested of events the inter-war during period by the course are invalid.
arithmetic. rather
the
temporary the war and
reproduction of future births
assumptions
on
A
net
forecasting a matter
rates
fertility
were
demographers
strate consistently
is to be a basis for
Before gross
"full
viz.: What relevance persons, scene have the demographic in the inter-war when period,
contemporary undertaken
other
and
does
and size of family if the outcome
the such
themethods exploited by R. Kuczynski, Enid Charles,
Service,
not necessarily of all parities (which to it is essential occupy beds), hospital a changing rate in terms birth of parities
mainly
of
imply a doubt widely
questions
well-informed
studies
birth.
after
Is
do?
can reveal
development
HajnaFs
and child
the cost of maternity
to marriage
due can
explanation, to rates are due fertility . . . etc.? allowances",
increased
smooth
among to the
spheres, it has
services, Health
of the complications
demographic analysis to resort to "sociological"
expected.
maternities.
in other
importance educational
of Birmingham
that
stage that the
and
the
number
City
no regularity under rates as large as in fertility it would those which have recently occurred, very provide discussion of population trends. little basis for a reasoned assumes that a reasonably For all such discussion orderly
recent changes rapid to appropriate provision the need for which services,
seeks
Office,
employment", "family If demographic analysis fluctuations lying irregular
"old be commonplace. entitled viously age" would is so low in the middle Since mortality age ranges, on of end communication focuses the other this in the birth
all
next
of a community needs age-structure A communication tion. 1951) previous (Taylor, demonstrated of adequate the importance provision to a level pre for a community in which survival
life and
Statistical
such
rapidly-changing
as the gross and net reproduc in a static situation;
a relatively
presume
situation
the picture they disclose
For misleading. highly incentive and imposed powerful rise of in a sudden result may may
be
followed which
by a spectacular
fertility*
does
not
instance, to earlier such
rates
a newly marriage shortly
fall during a period
materially
in
change.
* the term "fertility" is used, as this communication Throughout all demographers use it, to indicate the current rate of producing progeny. Biologists use the term with emphasis on the ability to produce progeny, a concept for which demographers use the term "fecundity".
fertility
(1947) 226
COHORT ANALYSIS OF FERTILITY IN ENGLAND AND WALES, 1939-50 r22-5
227
A
i
\ MARRIAGES
V. ^ q .^-"^ Ui
^""T^"""?***^
/
*
rr
^*T *'"
V
aSJ.I3 15 -j
1-4.
f
i
-.
\
H-
\
,-.
\ 5
30-
\
I
??
13-''
ill 1875
70
Fig. It
is the writer's
aim
i 90
*85
\\\
to
1.?Fertility
show
that
i '05
and marriage
smooth
and
are
Contrary past, we
apparent more to many see
shall
in England
to analytical methods by recourse intricate than previously required. in the recent opinions expressed that
and Wales,
replacement and that
is not a
happening further decline
in fertility is indicated. Such is the cohort method.* The earliest publications illustrating cohort analysis seem
to
McKinlay
be
those
of
Kermack,
(1934) on mortality
McKendrick,
i 'IO
i '15
and
rates, and of Barclay
* This is, of course, analogous to a Family Census, and en passant it is perhaps advisable to detail the reasons for not using the Family on Population. Census conducted by the Royal Commission The the birth boom. first is that the Census took place in 1946?before It is not possible to continue the analysis. The second is that the published volume (1950) has tables for Great Britain not split for age and parity. It is impossible to understand the situation without a complete analysis. The third is that the marriage populations used seem to be erroneous. Fourthly, the Census (a sample census) was voluntary, and of course excluded all data for mothers who had died before the Census date.
are of
the
background then available. was
Registrar-General of births down of application not available. prepared uses but index
on
(1937-8)
contributions
against material
of
first
by maternal the cohort Karmel
material it
l '35
| *30
l *40
l *45
l I95C
fertility;
but
these
1868-1951.
and Kermack pioneer
i '.
\
i 1925
i '20
rates, England and Wales,
trends
did exist in the disturbed period from 1939 to 1949, necessarily
\N-f-^\A
'. ! ,-/ W/\ \
i 1900
i '95
/V
J!
\
YEAR AVERAGE
'80
A REPRODUCTION RATES /
\ GROSS
O-SJ
\
YEARLYFIGURES
ii
YEAR
.
l-O-,-r^r-,-r^M-r
5
20.-FIVE
\
13'
to
current
In the U.S.A.
the
more
creditable
of source inadequacies Until when the 1939, a break to publish able
age, method
for data requisite were to fertility
has (1949) for a suitable an
develop marriage a monograph
since apparently cohort analysis, annual measure?the
fertility
in Australia.
by P. K. Whelpton
has
apparently substantially advanced the analysis of American fertility by cohort methods. Although the work is as yet unpublished, a review by Kiser (1952) describes
a novel
approach,
of less refined data
overcoming
than are available
the
defects
in Great
228 WALLIS TAYLOR Britain
use
the
by
of
"actual"
and
"hypothetical"
period. relevant
cohorts.
(2) The Cohort Method In the domain of mortality or morbidity,
as to the cohort referred procedure is comparatively both in conception simple a breakdown execution. Given of deaths
statistical method and
in
by age over to assemble i.e.
year, and
of
and
rates
at each
are
statistics it is thus marizes
referable.
same
what
would
age The
remained
initial
life of persons in terms of
handicaps, of birth,
time
constant
the
picture precise it is evidently
of
than
laborious
straightforward. cohort life-table of of
for only plete calendar current
the
changing
limited
utility,
cohorts
already and will,
that
of
at each
generation. life-table
is
the alternative,
a much gives hazards of it can
since
extinguished
referable the
utility
in relation
period
of fertile
married
life, especially a small fraction
is quite conditions, its application On the other hand, from the fact that difficulties apart by maternal
age
or
duration
under
more health, be com
is not
as
yet
for
obtainable
the
modern
a generation. involves special a breakdown of of marriage
is
countries.
to know of fertility we need and both calendar year at birth.
analysis age,
by
marriage
births, marriages and duration
tion
in connection
indeed
to
with
when morbidity from arises available
of
cohort,
i.e.
termination
of
the
reproductive
are
current
trends in the
unextinguished over
fertility
has achieved
By segmenting obvious that
already
have
a
for
in,
fertility three
children, which families, of a proportion
small
a further
added
importance of this knowledge the
be
having of such
proportion be only
cohort,
births.
however, stimulated
have
a high themselves
In
fertility
cohort
families
to measure
period,
in the change as a propor
events
external
a short
substantial
any investigated, a small effect measured
rate may have tion of all the previous into it may, parities,
birth.
The
if we wish
is obvious
relative
and reaction of efficacy to fertility. of to the the application the cohort method our problem reason of fertility, is for a further stimulus
study less simple
than
those
the
experience,
which
our
When
of
year
in
arise
concern
of
study
mortality a constituent indi
of
birth
the
is with
vidual is a sufficient criterion for the identification of
the
cohort.
our
When
we to have experience, same in one and the at
different
to
special
trend fertility and successively and
delay
of
fertility
and
at
marriage
the
fertility
a
calendar particular to different age The
reader to make
necessary
may this
year, groups here ask distinc
the same criterion by identifying define
of in
birth. this
obscured
our The
fertility answer
context by
promoting procreation.
for
cohorts
the
if we
year
concern
age
year. be of
i.e.
type, the mother's
individuals
year
Since
referable
tion if we adopted constitution
fertility that fact
the
it will thus be necessary of births, not merely of all the history
all marriages in the one calendar it would
is with
with
calendar
total
i.e. spacing pattern, to follow separately referable marriages
either
concern
reckon
ages.
both
influences
the are
the fact that procreation as is death, a unique event. is not, To marriages in one and the same year there may and will commonly be more before the extinction than one birth of the fertility
can
labour,
to peculiar to draw
subject if we
about
as yet
investigate
durations
whether
in contradistinc fertility the data requisite
conclusions cohorts
but
A special difficulty besetting the use of the cohort method
if we
the
marry
cohort
are primiparae is also essential
it
the cohort
mortality.
we need of mortality, to know analysis and deaths calendar births and year age only by at death, to relate deaths at age x in calendar in order ? x. to birth For cohort ym back ym year year
For
and
segmented
of
most
we
defined.
may
available only in recent British statistics (since 1939) and
that
but
example, so that
is of much greater approach to our present theme the because
cohort
i.e.
stated,
external
at
one
how the propor analysis, exhibiting births is changing first, etc., second, pari with the changing size of the completed family. is useful refinement for the reason already
hazards,
at
be most year, therefore, our concern when is with trends only to a much earlier date. From this point of
instructive
births
a
by
for
of
Thus, to
our
confine
tabulated
of marriage by duration are available, calendar year but with considerable additional
sense
embodies
of death
throughout a cohort such
if we
If figures
as
any legitimate on the basis of
subjected conditions
which
of assembly same cohort
the
even
laborious,
as well parity and the same
passu Such
age the
in contradistinction
life-table composite if current risks happen
more naturally is otherwise but
view,
of
life up to the to which
date
to total births.
tion
cohorts completed sum life-table which
a
duration
constitution
While
For
to make
possible the mean
at prevailing the customary
year of the latest
at
the cohort
by
more
the
make, a more refined
it is possible long period, born in a given calendar the same the death cohort,
one
somewhat
attention
also
a sufficiently for all persons
survival
attained
to the
the
of course, makes to one and referable
This, data
agencies both From
to
is
problems cohorts is that
of by our the
evaluate
simultaneously earlier marriage this
point
of
view,
COHORT ANALYSIS OF FERTILITY IN ENGLAND AND WALES, 1939-50 the fertility calendar
us
tells year age at marriage,
her
know
of a woman
experience
lar
in a particu do not
born
if we
little
very
the fertility
e.g.
of
experience
a woman
married
in
1940
at
the
age
of 30 will be different from that of a woman married same
in the
at
year
the
20.
of
age
on
rate
reproduction from
the
one
the
cohort
approach
hand, on
and
what
the
other,
is to liken the first to a snapshot of a procession the second
and
to a moving
If the procession
picture.
is orderly and uniform, the latter may give little information beyond that disclosed by the former, our
of
indices
acceptance as informative
health
is consistent
with
and
is not
community calamities. such
If we
great
the
life-table
customary measures of
or some
of
the
inadequacies will be actuary
the
ingly ; but the effect is operative for each completed during by
cordingly Consequently
one
year
the
prevailing there is no
ac is diluted and only in previous risks years. of the secular distortion
trends except in so far as the risk of death depends on
the year by the cohort during in which is our concern situation an epidemic situation is essentially this investigation more in which for diverse, though comparable, reasons the snapshot is wholly misleading. approach
of
the
reached
age
The
epidemic.
We have to deal with a period inwhich two variables distort
the of
tions
There
picture.
in
nuptiality
have
been
fluctua large which have
circumstances
of both hastened and delayed the assumption the responsibilities of parenthood. The essential difference between the snapshot and the moving picture is felt in more than one medical situation. Since it would be true to say that hospital reports still publish figures of duration of
stay
based
on
averages,
current-year
it
is not
trivial to remark that only two indices of duration are
We
meaningful.
might a census
approach
by
applying
the conventional
interpret
taking
its meaning
adopt on a
the given
snapshot date and
life-table method
as an overall
patients of
picture
the
base
in
practice,
liable
a
to we
therefore,
figures
and
discharged, to referable same
the
are
an appropriate procedure, for duration of stay
any
already duration
for
available
figures
small,
being In
calendar
to
therefore not
admissions In
year.
all
short,
circumstances force us to adopt what is in principle the cohort method; but we then do so less because hospital populations are subject to violent fluctuation than because the snapshot approach would be inconvenient and the disadvantages of the cohort vis a
approach referable
to
situations.*
the
in view, are
end
i.e. a
regard to duration
that may say and exaggerates
the
statement in most
trivial
conditions,
With
one
hospital
vis
current
of stay in
snapshot approach the disadvantages
all
of crude birth and death rates.
the evident. snapshot rates of an epidemic, death In the year prevailing a wide the so of age groups, and rise over range i.e. mean duration of life, called mean expectation on the basis of current falls accord calculated rates, cohort
on
day, error.
in choosing
must
figures
the
when
to major epidemics of the occurrence
imagine
catastrophe, of approach
large sampling have no option i.e. we
because
question census
duplicates
community
experience
subject
to one
any
necessarily
to bring into focus the A helpful metaphor differences between indices such as the expectancy of life in the customary life-table and the gross emerges
conditions; but the usefulness of this procedure, not as yet applied to the writer's knowledge, is open
experience
of a woman born in 1900, up to the end of her reproductive life (say 1945) will be different if she is married in 1930 from what it will be if she is not married until 1940. Similarly, the fertility
229
of current
to
It may
to clarify
help
for a new
the need
approach
to an evaluation of current trends of fertility if we contrast in which situations the schematically of marriages and alter without may
incidence taneously,
births, any
singly concurrent
or
simul change
in fertility as exhibited in Tables I - III below. Table I exhibits the fertility experience of a hypothetical static population with fixed size of the completed family throughout the period covered, the only variable to the total number of births being a temporary
rise
compensatory stable level
temporary to which it
illustrative
we purposes, 2-child families
the returns.
of
significance
For
all marriages the same way,
there is evidently no difficulty
Here the
occurring second birth
a
eventually assume that
by a former
followed
below
in spaced in the second year of marriage in the fifth of marriage. year
produce a first birth and
rate
in the marriage fall
the
relevant
in recognizing
situation.
Table II exhibits a hypothetical static population with fixed nuptiality. As before, fertility is also constant
over
the
and
covered
period
at
level the spacing of the family being in Table
I.
Here,
we
however,
same
the
initially as a
interpolate
tem
porary phase during which the second birth follows more rapidly after the first, the second birth then occurring
in
the
may distinguish last,
all
second
third
year
three periods. births
will
be
of marriage.
Thus
we
In the first and in the referable
to one
cohort
but during the middle period they will be referable to different cohorts. Again it is not difficult to see what has really happened.
*Mental hospitals constitute a special case since clearance for most other types of hospital cases does not involve a delay of more than 18months if we base our figures on discharge dates.
230 WALLIS TAYLOR Table I OF MARRIAGE
IN INCIDENCE
CHANGE
BEING
(BIRTHS
CONSTANT)
Births Marriages
First Second
Year Number
100
PhaseNumber
?
1y
y +1001
50
100 100 100
Corresponding date of marriage of cohort
{stable)
200 j/ + 7
{temporary rise)
y + 8 3 50 + 9 .y
{secondary fall)
12 4 13 14
j>+ y + >>+
62 200 y + 100 200
?
j
OF
ZZ
200 >>+ 7 50 j>+ y + 9 y + 10
+
200
1
100 .y
+
200
2
50 >>+ll 100 ^ + 12 100 y + 13 ^+14 j>+ 15
Table BIRTHS
300+ 4 150 + 5 250 6 250 7
100 y 100 j> 200 j> + 200j +
8
50j> y50 + 50 ^ 150 50 ^+11 100y
Total
?? ?? ??
y200100 100 j>
j + 5 6 +3300 + 100 ^
15 100 y +100 100 100y +16
IN INCIDENCE
Z Z y y +?2 j; + 3 y + 4
50 50y +10 50 50 j +11
0ta6/>///year /eve/)
CHANGE
?
100 100 y + 2 100 y+\ 100 y + 3 100 100 j 100 +4 100 j> 100 +5
Corresponding date of marriage of cohort
Number
100 +
8 9 150 + 10
150
200 + 12
II BEING
(MARRIAGES
CONSTANT)
Births Marriages-" First Year
Number 100 100 100 100 100 100
j>1? y + 1 y + 2 y + 3 y + 4 y + 5
100
y + 6
2 100 100 y +7 100 8y+ 100
3 y + 9 100 + ^ j+11 100 100 + y
common fixed
namely
period,
this
can
vary,
discloses we
can
Evidently a much
j>+ y + y + y+11 y + >>+ y + y +
8 ? 9 10 ? 12 13 14 15
in Table
III,
discern
with
to one
a
blurred
the
a view
the
calendar
stable
the year.
true only
100
and y +? 5 ? 100 ? ? 100 ? ? j>+ 9 200? j>+ 10 ?200 y + 11 200 ? y + 12 200
situation so highly simplified for heuristic purposes,
+ +
300 300 200
? ? ? 200 200
6 7 8
we are of any real situation be true a fortiori will not be to encounter, since a real population with of any major and the effect change or total to spacing, family respect nuptiality, it must
fertility will be confused by minor fluctuations, especially in communities where family limitation has
become
a
progressively
more
common.
The nature of the cohort method of exhibiting current trends of fertility and the reason why it is essential
change if we
of marriages fertility If this is true of
100 J 100 y ? ? ? ? ? ?
+
Total
likely static
From picture. in of changes
significance to disclosing the to have occurred,
1
? ? .y+ 2 ?200 ? j + 3 200 and 100 y j>+ 4
100 100 100 100
both
pre-existing
>>+
? ? ?? ? ? ? ?
100 100 100
I ?
the record of total births
more
suspected evaluate separately
referable
as to
returning
level of both.
birthrate, in fertility
+ 5 y100 j; + 6 y + 7
rate and the spacing of the family for a
nuptiality
now
?
__ ? ?
__
? ? y100 100
to the two foregoing situations, a static we and population,
fertility
simultaneously
brief
100 10100 100 12 100 100 100 y +13 100 100 y +14 100 100 y +15 100 100 y +16
Corresponding date Corresponding date of marriage of marriage Number of cohort of cohort
? ?
the framework of the same highly schematic
Within assumptions may
Number
? ? ? y y + 1 v+ 2 y + 3 + 4 ^ 100
100 100 100 100
-,-1 100
Corresponding of marriage of cohort
Number
Phase
Second date
to adopt
such
a method
in present
circum
stances has thus been briefly indicated. It will suffice if we relegate to the Technical Appendix (p. 242) details of assembling the requisite data from the available official statistics. Here, for illustrative
COHORT ANALYSIS OF FERTILITY IN ENGLAND AND WALES, 1939-50 COINCIDENT
Table III IN INCIDENCE OF MARRIAGE
CHANGES
AND
SECOND
231
BIRTHS
j Births Marriages Number
|
Year
100 100 100 100 100 100 200 200 50 50 50 50 100 100 100 100 100
First Second Corresponding date of marriage of cohort
Number
y ^+1 y+ >>+ y + y+ y+ y + y + y+ y+ j>+ y + y+ y + >>+ y +
_ 100 100 100 100 100 100 200 200 50 50 50 50 100 100 100 100
2 3 4 5 6 l 8 9 10 11 12 13 14 15 16
Number
j + 10 y+n >>+ 12 j>+ 13 y + j>+ 15 I
the
purposes,
values
for
1939
the
one,
are
cohort,
given (Appendix Table A, p. 243). Picture (3) Contemporary The foregoing sections have briefly indicated the nature of the problem with which this communica tion
and
deals,
suggested
which us
force
the experience
by
refined
methods
sufficed for basing an intelligent
data
upon events
prognosis recent Do
for more
the need
than have hitherto
us
provoke
to
ask:
to
conclusions repudiate of the inter-war years
?
What immediately follows states briefly what is essentially new about the fertility experience of the decade evaluation In
of
the
we
to
propose
outlined
in Section
employ
2 to an
decades
data
available
1919-39,
with regard to Britain as a whole point to the size of the completed family interpreted within the framework
of
decreasing the mean
without
married in
cohort major
were
likewise
in Britain.
fluctuation
in
conscription
1938
enter
rates undergo Nuptiality annual total births within wise.
Though,
for
the
proportion same level and to no major
the
the introduction on
a
new
of
stated,
we
in the
sense
on
based also
that
any
appropriate
index
civilian
Such
population.
is the
the experience of situation which
the
inter-war
we
can
expect
Such years. to clarify
only by the approach outlined in Sections 1 and 2. We shall first attempt (in Section 4 below) to bring into perspective the significance of the dis putable immediate post-war birth boom. We shall then attempt (in Section 5) to evaluate current (i.e. 1939-50) fertility in terms of replacement by an to
referable
employ
the
cohort the
throughout
we
which
procedure
It
sections.
succeeding
will then be appropriate in Section 6 to use the cohort method to disclose what is the size of the completed family referable to different ages at in
Finally,
7, we
Section
an issue first raised by Kuczynski possible marriage seemingly
consequences under the
of
review of
encouragement
Nazi
regime, level of age
lower
sustained
shall
in relation to the early whether
i.e.
at marriage
(4) EVALUATIONOF THE POST-WAR BlRTH BOOM The first duty of a summarizing index is to
no
comprehensive numerical data before the Population Statistics Act (1938), we have very good reason for believing that the fertility pattern was also unstable,
the
will suffice to restore fertility to replacement level.
period.
have
500 y + 6 + l y350 100 + 8
then is the situation which has understandably provoked scepticism with reference to forecasts
drastic fluctuations and the next decade do like
reasons
of
age-composition
marriage. of
the
subject
From we
as steadily Meanwhile
approach fluctuations.
of marriage and age both at much remained case
any
the
Z~~ Z
difficulties disclosed by the heuristic approach leading up to Table III coexist with the concomitant difficulties arising from the fact that war itself entails temporary but considerable changes in the
index
situation.
two
the
how
and
1939-49,
the cohort method
? ?__ ? ?? ? ? ? ? ? ?? ? ? ?200 y ?200 ? y+ 1 ? ? 2 200 y+ ?300 ? y+ 3 and 200 y+ 4 and 200 y + 5 ? I 50 y 50 ? ? 50 ? ? j + 9 150 ? y + 10 ?150 ? ? j>+ 11 150 ? ?200 j>+ 12 y
? ?y+l y+2 100 y +3 4 100 y+ 100 + y 5 6 100 y+ + l100 8 y +?100 y ?+ 9 ?? ? ?? 50 50 14 50 100 I
y
-Total
Corresponding date Corresponding date of marriage Number of marriage of cohort of cohort
of
spacing of births would also have disclosed abrupt changes. Thus we have a situation in which all the
as
they situation.
A The
crude
live
birth,
marriage,
rates are valuable indices in so far information
condense second
is to disclose situation.
sense
In this
summarize.
and reproduction
and
not
underlying obvious
solution
relevant subsidiary
trends
to
a
stable
requirement
in a changing
of averaging
by
one
232 WALLIS TAYLOR or
method
another
situation
has
the fact
as early
is
rarely it is
changed, as possible,
If
satisfactory. desirable
to
a
fluctuating
period.
in fertility rates is to be expected, which
the 1947 birth boom was hailed as a Though substantial change in fertility habits, we shall now see
the change
that
in family
accounts
building
for
the
years,
argument
ever
has fallen fertility we shall now seek
since.
a
and
important,
the
crude
become
the necessarily
delayed
"damp
disappear. will thus
produce incidence rate more
live birth
since first births,
marriage, the arithmetical
which
may parities of marriage
higher variation
in both
the during variation
after
rapidly
ing" of oscillations
was
than
Any affect
previously
true.
is
Such
follow
increasingly
great part of the boom. Despite the fact that the 1947 cohort is of somewhat higher fertility than in recent
and marriage indices that occurred a falling With size more family
fertility
average yet a short-term are rapidly in a period when indices and a long-term is unrevealing. average
is ephemeral
1 (p. 227) shows the great variations
Fig.
know
To
to substantiate.
exhibit
in annual
the fluctuations
fertility,
2.200-1 LIVE-BIRTH RATE DURING CC* YEAR OF MARRIAGE .
E
^?
!X
.?^~
VALUE-, j ! SAME,APPROXIMATE
9
1,800
'
? eke 5i,2oo
5i,ooo -
?-6oo.i
5:i
-j
4 ,
r ., :? -.
.jj.?-i???r
.;
pn
i31
I l..j ! 2
!
3
2
i_ir?-??L-J_-.___?i
2oo-
rf-s
ch3
i-5-i
8oo-
400-
rvJ.
\~\
L6-,
. ,
\2 \
3 i
|2??r
1-l.___J-1-1-1-1-1-1-1-1-1-1?_J-1-L?J-1-1-1-1-1-1-1 0J
YEAR
1939
1940
1941 ,
Fig. 2.?Cohort
1942
1600
1,400
r?
_l-1 " ;
;
! 10 }
L !
r?i
\-A ^
Cjlj//,
>/?KCEk i<j im
i_i
1943
1944
,-?"i
-I
.
<
;/
?
X-Ul?
LL
i hr
!4
Lik
'"rh-^K-LLi
^
r_u
~l
r
1/1r~?b?I_ 2
2 2 iLL^k?^:?L-? 2 2.
l2
A?k\._,
m'/EVrfKffih--D?3 \?V A?K sk^-k rrK-r?
k?
-k?
k..i_
rh-h
2
2
111
i_M???.?.?
1945
1946
?? i i
live birth rates by duration of marriage,
1,800 r.-jr-j ?n '
V-i
To"
f
L'.J 'To"!60Oi
?.?k?
I-1?--\'-'"\
N
I oc
x Hot" L"~ T^?H ^._
1947
1948
1949
1950
arranged by calendar year.
I LIVE-BIRTH RATE DURINGX,H i
VEAR OF MARRIACE
value
SAME> approx|mate
\"~~IHL-":PR"':PP---i?i
LZl ~H- "Lju-ffi.iT-r"TZl
mipooj uj
> goo
6 ! 5: h??L_L --h??'?"' l_i-"'\T\ 5 ^ r ~\T\ I* I L_L-H?!'" 5 I rr\.rr"S-[_-""!?' I A?.?4
?L
g 200
Ll
H-r^^L
U---H'
3
3
2
2
I
I
5
4
_ f5 " -L? 4 4 \-""\?I I
-h-h???,?i
2
Ll --r?.?r""?f 2 2
l_l...._U.Q.?.Q....J_J.U..._-.U--....l_J.U--.._LJ.I_l.lJ 1 o
1940 Fig.
_
>
?h-?.[?\--\?.?.\T\\?.?1
COHORT 1939
N
,.A-.-_!
1941 3.?Cohort
1942
1943
1944
1945
live birth rates by duration of marriage,
1946
1947
arranged by cohort.
1948
IT I """I I 1949
1950
COHORT ANALYSIS OF FERTILITY IN ENGLAND AND WALES, 1939-50 Table
IV
IN COHORT FERTILITY (Mothers aged 21-25 years at marriage)
YEARLY
RATES
CHANGE
PERCENTAGE
233
Cohort Year 1939
1940
First Parity 1-13? 1940 1941 -51+4? 1942 -14-32+14 1943 -27-29-38+21 - 32 - 33 1944 - 40 - 29 1945 1946 0 +37 - 37 34 1947 - 58 - 53 1948 - 43 ? 1949 ? ? 1950
1941
1942
?
? ? ?
- 33 - 40 +34 - 30 - 57 - 50 - 30
Second Parity ? 1941 + 97 1942 +10+155? 1943 -3+14+188 1944 +12+23+47+221 1945 -36-20-14+7+177 1946 -+43+29+24+22+30+221 22 14 1947 - 40 1948 36 ? 29 1949 ? ? 1950
42 44 +19 - 20 - 59 - 44 - 33
-
? ? ? ?
? ? ?
-
32 29 19
? ? ? ? ?
we have related fertility rates to the year in which (Fig. 2). Thus due to different
they occurred rates contains
each
vertical
cohorts,
but
column represents
the fertility rates of any one calendar year (each vertical box refers to rates produced by different rates for the 3, where years are vertically imposed, The appearance. rapid regular
cohorts). successive more
Fig.
same
cohort
shows
in
a much
is already standardized for fluctuation
in marriage reasonable
numbers,
It is now marriage, Gt. Britain
virtually
but
also
and
disappear, possible.* not affect
Whereas fertility. is committal in the sense
marriage it cannot that
the intervention than once without legally occur more of a protracted in one the births interval, produced occurrences of a like do indeed affect future year nature speak
in
same
the
We may, therefore, family. or as of births postponed
meaningfully
expedited. Thus Fig. 2 shows that the high values of 1947 fell rapidly in 1948?a change which should be fairly equally distributed over all cohorts (Fig. 3). Table IV classifies the changes in cohort habits by year
of occurrence
for
the most
important
age
group
by exhibiting the percentage fall or rise of succeeding years
relative
Algebraically
to the
the values
immediately tabulated
year.
preceding are:
( Specific Fertility Rate of _ Specific Fertility Rate of J Cohort xDuration (ai+ 1) Cohort x Duration n I Specific Fertility Rate of Cohort xDuration n
^ I X 100 J
* In Fig. 2 approximate values referring to complete cohorts for marriages before 1939 have been inserted. They are not relevant to Fig. 3 and do not appear there.
? ? ? ? ? ? ? ?? ? ?? -
? ?
?
? ? ? ? ?
? ? ?
?
?
17 58 44
? -
? ?? ? ? ? ? ?
?
?18 56
-
? ? ? ? ?
14
? ? ? ?
? ??
+222 13 0 15
a therefore, will appear
1949
?
+136 4
calendrical
? +100 ?
all
affecting
change
as a horizontal
change.
Clearly
a change occurred in all parities and all cohorts in the 1946-48 period. In 1946 many values are in sign,
reversed smaller
than
and
customary. this after
but
1947,
are much values the negative are positive Some values all
date
tive.f
It is clear, therefore,
showed
a reversal
in all cohorts. and
only in
+10 20
Here, cohorts
in of
fluctuations
Fig. 2, which
becomes prognostication events clear that external
?? ?
-0+10+15+29+271 18 14 15 15 31 26
25 26 21
?? ? ? ? ? ? ? ?
? ?
1948
1947
? ? ? ? ? ?? ? ? +32 - 62 - 45 - 41
? ? ? ? ? ? +24 - 45 - 53 - 43 - 39
0 44 27 54 41 38
-
1946
1945
? ? ? ? ?
? ? ? ? +18 - 56 - 15 9 - 58 - 41 - 40
-
?
1944
1943
By
normal
now
compare
We
Tables V and VI classified In
these
of
are
this
the
rates 'the and
shown actual
show
how
are
nega
1947
of marriage
1948 this effect has disappeared situation
prevails.
(overleaf)
yearly far
of any fertility rates the yearly
show live birth rates and
of marriage for values
on the appear the cumulative
same
(VI). advance
cohort
year. duration
same
the
line.
horizontal
rates
rates in
of fertility.
effects
the cumulative
by duration the Tables cohort
each
First
at all durations
of trends
a more
one
except
that 1946 and
The or
and
(V)
after
cumulative in
arrears
is
at any cohort time, particular the changes in which show years
which led to this situation took place. Thus Table V will show the effect and Table VI the incidence of changes in fertility. Two we may between we
may cohorts.
are admissible. First of comparison types a norm the difference and measure postulate and this norm. cohort each Alternatively measure between different the differences To
represent
the
norm
we
take
a
simple
t The final horizontal value on each line is the percentage change in the second year of marriage and, being heavily affected by its proximity tomarriage, should be ignored in this argument.
234 WALLIS TAYLOR Table V FERTILITY RATES
CUMULATIVE Duration
(TOTAL BIRTHS)
Cohort
Marriage Age Group 16-20
5 6 7 8 9 10 Age Group 21-25
6 7 8 9 10 Age Group 26-30
8 9 10 Age Group 31-35
9 10
of-Average 1941 1942
1939
1940
1 465 7482 9783 4 1,187 1,368 1,547 1,691 1,873 2,027 2,145
324 602 843 1,046 1,242 1,400 1,620 1,816 1,954 2,066
256 521 728 919 1,073 1,279 1,484 1,626 1,735 1,826
255 525 744 924 1,146 1,382 1,550 1,681 1,792
2321 464 2 6303 7974 9485 1,100 1,217 1,362 1,484 1,569
189 406 600 771 937 1,067 1,241 1,392 1,497 1,579 1,488
177 396 574 743 874 1,050 1,215 1,330 1,415
182 419 612 761 947 1,137 1,271 1,382 1,471
1801 380 2 5173 6644 802 5 9386 7 1,044 1,166 1,266 1,335
155 337 510 666 813 930 1,077 1,199 1,284 1,346
160 355 521 674 795 945 1,080 1,175 1,243 1,298
1 174 3502 473 3 5914 7005 799 6 8727 9388 986 1,014
147 313 446 568 683 768 851 914 953 976
157 337 479 607 707 809 891 946 976 995
1943
1944
275 299 572 579 779 810 998 1,057 1,247 1,260 1,433 1,428 1,596 1,568 1,720 ? ? _________ 203 463 635 818 1,019 1,167 1,299 1,400 ________
1945
1946
1947
1948
284 577 853 1,077 1,269 1,429 _______
295 645 911 1,139 1,334 _____
400 763 1,051 1,287 ?
416 777 1,042 ? ?
? ? ?
?
?
1,414 1,585 _______ 1,743 ? ? ?
1949
1950
430 760
410
? ? ? ?
342 643 874 1,070 1,242
?
1,877
2,012
237 497 713 928 1,090 1,230 1,344 _______
216 505 747 934 1,093 1,229 _______
235 575 803 996 1,162 ?
? ? ?
296 585 795
266 530
? ? ? ?
246
233 496 695 865 1,009 1,140
220
207 442 622 774 900
? ? ? ? ?
1,264
1,373
1,467 _________
1,545
164 374 552 689 853 1,005 1,118 1,206 1,269
185 ' 220 189 224 421 461 455 535 581 657 670 743 831 754 844 916 922 968 990 1,060 _____ 1,048 1,106 1,079 ? ? 1,160 1,195 _______ 1,238 1,197 ________ 1,265 _________ 1,326
157 348 493 609 727 825 894 940 967 _________
172 378 516 653 773 861 926 966 _______
191 394 564 705 806 884 937 ______
313 617 845 ?1,037 ?
?
178 417 585 716 818 896
? ?
_ 941
?
283 559 760 924
? ?
?1,007
192 454 622 755 861
256 521 710
? ? ?
?
222 450 600 719
? ? ? ?
? ? ?
228 467
? ? ? ?
?
209 422 560
? ? ? ? ?
?
190 390
? ? ? ? ? ?
1,112
181 387 534 658 759 835 895
188
_
970 995
Italics ?= < Average.
over
average
the period.
If,
in fact,
the
1947
cohort
represents a new level of fertility likely to be followed successive the norm will not be meaning cohorts, seen this is unlikely. ful, but as we have For comparison of the alternative type, we assume we more that a cohort for which have data has
by
a more
reached
stable
the
compare should
be
durations
1939
that
noted here
We therefore, shall, position. with It other cohort cohorts.
necessarily
the
of lower the averages refer to larger numbers.
Perhaps the most striking features of Tables V and VI are the high fertility and distinctive character of the 1939 sub-cohort of women married in the age group 16-20. It is different both from later cohorts at
married in
same
the
same
the year
at
from age and different ages.
fertility in the first year of marriage cient
to
keep
this
cohort
higher
those The
married very
high
has been suffi
than
the
average
the whole
throughout about the
reason
for
We may period.* only speculate it may this. For have instance,
been due to the 1938 political situation, possibly to in 1938 of the 21-year-old male age conscription to
group, incidence
in "peace seems
actually
of the quarter for occurrences mother.
from
relaxation
and to belief
but year, in months it was
Certainly
the
war
1938
scare,
in our time". The highest to have no or not
in
been
are
returns quarters to due
the
by the
third
available of age outbreak
of war which occurred far too late in 1939 to have any
effect
upon
the
fertility
of
that
year.
It is also noticeable that in the 21-25 age group the first year of the 1939 cohort showed an extremely high rate of fertility. The same is not true of the older cohorts. It is interesting to see that the 1939 * If the averages are re-calculated after the 1946-48 cohorts have experienced ten years of marriage this may not necessarily be true.
COHORT ANALYSIS OF FERTILITY IN ENGLAND AND WALES, 1939-50 VI Table FERTILITY RATES
YEARLY
235
(TOTAL BIRTHS)
Cohort
Duration ofMarriage Age Group 16-20
10 Age Group 21-25
9 10 Age Group 26-30
9 10 Age Group 31-35
7 8 10
1942
1943
1944
1945
1946
1947
1948
255 270 219 180 222 236 168 131
275 297 207 219 249 186 163 124 ?
299 280 231 247 203 168 140
284 293 276 224 192 160 ?
400 363 288 236 ? ? ?
416 361 265 ? ? ? ?
?
?
295 350 266 228 195 ? ? _______ ?
?
?
203 182 260 237 172 193 183 149 201 186 148 190 132 134 111 101 ________ 89 ________
237 260 216 215 162 140 114
216 289 242 187 159 136
235 340 228 193 166 ? _____
313 304 228 192 ? ?
296 289 210 ? ? ?
164 210 178 137 164 152 113 88 63 _________
185 236 160 173 168 126 112 78 ________
220 235 202 187 146 116 89
157 191 145 116 118 98 69 46 27 _________
172 206 138 137 120 88 65 40
1939
1940
1941
465 1 2 283 3 230 209 4 1815 6 179 7 144 8 182 154 9 118
324 278 241 203 196 158 220 196 138 112
256 265 207 191 154 206 205 142 109 HI 91
________
232 1 2 232 166 3 4 767 5 151 6 152 7 117 8 145 122 85
189 217 194 171 166 130 174 151 105 82
177 219 178 169 131 176 165 115 85 73
1 180 2 200 3 137 4 147 5 138 6 136 7 106 8 122 100 69
155 182 173 156 147 117 147 122 85 62
160 195 166 153 121 150 135 95 68 55
1 174 2 176 3 123 4 118 5 109 99 6 73 66 48 9 28
147 166 133 122 115 85 83 63 39 23
157 180 142 128 100 102 82 55 30 19
|
_ 125
______
224 311 208 173 144 ?
189 272 209 161 137 HI
1949
______
283 276 201 164 ? ? ______ _ 101
Average
430 330 ? ? ? ? ? 155 ?
410 ? ? ? ? ? ? _ ? _
342 306 243 215 199 185 173
266 264 ? ? ? ? 139
246 ? ? ? ? ? _
233 265 203 181 165 153
_
100 80
220 ? ? ? ? ?
205 238 182 161 146 130
228 239 ? ? ? ?
256 265 189 ? ? ? 117
1950
128 107
79 62 191 203 170 141 101 78 53 _______
178 239 168 131 102 78 ______
192 262 168 133 106 ?
________
222 228 150 119 ? ?
209 213 138 ? ? ?
190 200 ? ? ? ?
188 ? ? ? ? ?
181 206 141 127 109 90 71 54
36 23
Italics = < Average.
cohort
ahead keeps that it may the period.
in
several thus age groups, a maxi represent ultimately For the 26-30 age example,
suggesting mum for
group of the 1941 sub-cohort, which than
twice
1939,
reached
a
higher
the very
recent
cohorts
value
the
during
only
and
in several
cases
earlier
years
the most
recent
values
are similar to those of 1939. It is now of interest to separate the cumulative values to see in which years cohorts differed from the average for the whole period covered and from the marriages of 1939. Table VI now shows with the
same
by
age
construction at
marriage,
yearly duration
total of
sui generis,
live
birth
marriage,
rates, and
from the 1939 cohort, which
the cohorts (i) pre-1946, (ii) 1946 and
to
of marriage, particularly for the higher age groups. It is clear, however, that in general 1947 represents a peak,
case
started lower
be surpassed by the 1939 cohort. It is true that the 1939 cohort is quite often less fertile in comparison with
cohort year. Apart
For
all
start when
fall again
into
two
is a
types:
after.
the pre-1946 cohorts the they are below
have average
a period at the for duration,
followed by a period, usually of 2 years, when they are higher, which is followed by another low period which always includes 1949 and often 1948. The 1946 and later cohorts are with one exception always higher than the average. This fact again clearly demonstrates the experience of 1946 and 1947 as a are 4
temporary
All
phase.
and affected, duration years'
all
recorded
without exception more than having a low value show for
cohorts
cohorts
In addition many show at succeeding fertility. least one year of preceding fertility lower than 1939.
236 WALLIS TAYLOR In
the
discussing
cumulative
we
rates,
saw
that
fertility;
as we
yet,
have
in fact all cumulative duration
the final
seen,
of
at
married
1946, of
evidence
and
that
they little
subsequently trend. We have
new
any
The
seems
to
be
a peak
All
subsequent fertility, though high, falls pro portionately from the 1946 and 1947 level.
and
For
two
a Cohort
reasons
it
accurately in the period dealt
fertility
statistics originated for
only
with.
tenth the
First,
year relevant
cohort
of
Secondly,
data
published
the
of
age
on
16-20
graphs
same
for the
is plotted for prepared
each
pattern.
to fit a single curve to the entire in that
unsuccessful inconsistent
with
they
either or
(a) above,
known
end
satisfied
for
Although
half
for a longer
are data
the Similar
10 years,
9, and
determine
in 1939 (the first full year)?so
the earliest
available.
period
to
possible the beyond
at
in
and
graphically,
to each cohort
pattern. fertility However, each group taking by age at marriage separately, a quadratic to the average fitted of the parabola of all cohorts values at durations cumulative of 7, 8,
Index
is not
the
shown
best
figures were a maximum
distorted
Fertility
Cohort
Replacement
rates
marriage that
the
of
Extrapolation Rates
the
to two
regard
referable
attempts
10-year showed
plateau,
and
(5)
is
married group the same graph. show age group
evidence
a new
not
and
result
4 fertility
Fig.
from which to estimate the future fertility of the later cohorts (1946 and after), but they show less tendency to be abnormally high after 1947. Thus 1947
to extrapolate criteria:
attempt
due
covered.
no
show
shall
with
of
loses
than
in
grouped
have its maximum at the end (a) the fitted curve must the reproductive 45 years of age); period (approx. relevant informa (b) the fitted curve must incorporate tion with to fertility reference in the period experience
the
different way, for durations of less than 9 years. place For the ninth it is actually above We year average. a thus the post-war had boom may say that only on effect all cohorts of earlier date temporary age and
we
Accordingly, known values
than the
values are, higher
The 1939 cohort averages. 21-25 in a somewhat behaves
are
10 years
quinquennia.
is, and
value
over
of marriage
durations
for the 1939 cohort married at the age of 16-20, the high initial year is followed by 6 years of low
of
the
first
that
this
conditions.
married
10 years' covers by
part of fertile married
less
young
life is complete
their fecund married
it is clear
for
both
those
of
duration far
the most
than
by the
marriage, substantial
life. For those married
older
3.400-I
280oJ
MEAN AGE OF COHORT / 19 20 21 22 23 24
18
25
26
8
9
2,600-j 240oJ
sesss^-'
.^-^*
3,000-1 27 28 .-^
29
30
31
.'-^33
34
35
36
37
39
40
41
-1-1-121 22
23
24
38
43
44
45
46
-1-1-1 25 26
27
28
29
42
/^
?2.200-
/^
^2000-
/
S*
IO ,,BOO| /0^^ 1.600-1 //^y/
a:1'400' Jy4 /
5
I ///jVs^ ^Jsw 800j 600-|//J/
200-J
OF MARRIAGE DURATION
O-l-.-.-.-.-.-.-1-,-,-,-,-,-,-r--1-16 4 5 I 3 2
7
Fig. 4.?Cumulative
IO
II
12
13
14
15
16
17
fertility rates for all cohorts married
-.-118
19 20
at the age of 16-20 years.
COHORT ANALYSIS OF FERTILITY IN ENGLAND AND WALES, 1939-50 more
is even
this
to smaller
an
index
influence
The
of
is now
of changing fertility and nuptiality. the
at
married
percentage
trend.
each
con
will
tempo the
during
period by the extrapolated number of live births which each age group will produce by the end of its fertile life we have a weighted Index of Marital Fertility (Table VII). This index is independent of shifts in numbers married, since it is based on It is strictly applicable only to the proportions. exten under but the subsequent discussion, period as more sion of the cohorts, will data are available, a revaluation at of the trend of permit fertility intervals.
yearly
Table VII INDEX OF MARITAL
COHORT Age at Marriage
16-20 3-309 2-259 1-605 1-006 0-450 0-075
21-25 26-30 31-35 36-40 41-45
the
Whilst polation of the
not
does mean
so
rate
replacement
derived
does
of replacement i.e. the experience analysis, a reversal of fertility register of
1-02
female
children
if all women replacement to compensate sufficient for
above
women
to marry,
completed
the
in
the
cited figure die before
who
trends.
The be
It
failure
just is not some
of
to
referable
the for
compensates the
reaching
the average
in fertility,
but
of total fertility from the peak is
marriage cohorts.
in
There
general are,
steeper therefore,
the yearly
end
decrease
in the first year of than
for
three
admissible
earlier
years later
will
be
initial values of more
compensated
by
a
recent
decrease
is higher than in most for
compensates
seemingly
if the present themselves.
necessary to replace
the
cohort
durations live births
of
the
of
generation
Size
we can rates, extract, in of marriage, the size of family of current marriages, i.e. without fertility
by a previous
to children
Whilst
marriage.
interest, it also makes of
progress
possible an
and
cohort
each
years of
duration
at
1939-50, marriage
age
range
successive
(21-25) of the
stages the
throughout
each entry exhibits size
common
the most
during
the
even have
decennium;
of families of
the proportions
a to a particular after cohort of marriage. 5 per cent, of families that only 10 years of marriage) duration (e.g. after and than three that approxi children,
referable
at high more
mately children
20 per cent, have at this duration
Whilst
as
in
years.
(?) that their total fertility will eventually be higher, although the gradient at later durations
yet
we
have
many in fact note
the mean
none,
1-5. parity
cent, infertile per marriages a live-born and we should child, produce of that the very much smaller proportion of
the
that do
20
in the
tile marriages
of
number
being approximately no break-down by
(vide supra), it is unlikely
for the extrapolation
smaller
infer cohort
married
earlier
here
(16-20 not shown here) is in great part due to the large these
conclusions:
(0 that the higher
experienced the rate
duration specified It is noticeable
of fecund life. Fig. 4 shows that the 1947 and later cohorts are above
are
analysis
given
1939-50
would
been Further,
in marriages of* higher duration, a more than proportionate causing seem It would that active therefore fall.
are
married
The
married.
being
extra
steadiness
of
never
has
period.
continued possibly
subsequent measures
an
1 025 an
values,
estimation of the present birth situation in terms of completed fertility. Table VIII (overleaf) exhibits the history of cohorts
fertility of all women married at existing
rates, women
mortality married
although
be
thus
given terms of
gross an not present but substantiates
picture
figure
to
this is of ulterior
on
based
(1947^9)
cohort
the initial high level. The tendency since 1947 has been one of falling fertility; and this ismost likely
reference
the relative data, is a measure of its value.
cohorts
encouraging the previous
is at present
index
and
cohorts,
for 105-2694 30-9765
index =
the earlier
(6) Family
211-2569
Replacement
of
of decrease at low durations previous
From
the known
of
by our third assumption in the history of the
Product
100 0 Total Sex ratio = 0-4852
that
be above
REPLACEMENT
19-7 65-1873 46-6 19-3 7-7 7-7462 4-2 1-8900 01875 2-5
durations.
with regard to both height and gradient. A reason for favouring conclusion (ii) is that such a projected average as the high fertility prescribed
mothers
Marriages at Given Age (per cent, for period)
Total Births (from extrapolation)
those
(iii) that fertility of the later cohorts
By multiplying age
at
years
to
possible the current
to
appropriate
may not differ from that of the earlier cohort
tendencies
this
accelerate
Index.?It
Replacement struct
true. size may
family
237
proportion
marriages children after of
centage
of pre-nuptial Indeed, conceptions. an average of 2-0 have produced 10 year's The mean per marriage.
infertile
at
marriages
durations
selected
for the group aged 21-25 is as follows: Duration
of Marriage
Percentage
(years)
Infertile
2
4
6
8
10
1 54
35
27
23
21
I
238 WALLIS TAYLOR
Cohorts Duration of Marriage (yrs)
Table VIII SIZE OF FAMILY (LIVE BIRTHS) compared at Same Durations of Marriage (Mothers aged 21-25 at marriage)
Number of Live Births by Present Marriage
Duration
Cohort-,-of 0 1939 1940 1941 1942 1943 1944 1945 1946 1947 1948 1949 1950
1
2
3
4
1
77-3 81 -5 82-6 821 801 76-8 78-9 770 69-3 71 -2 741 75-6
2
, i ! I
22-4 18-3 17-3 17-8 19-7 230 20-9 ! 22-8 t 30-4 j 28-4 25-5 241
3
0-3 0-2 01 01 0-2 0-2 0-2 0-2 0-3 0-4 0-4 0-3
I i i
? ? ? ? ? ? ? ? ? ? ? ! ? _i_ ? ? ? ? ? ? ? ? ? ? ? _
1939 1940 1941 1942 1943 1944 1945 1946 1947 1948 1949
57-6 62-3 62-7 60-5 56-5 53-5 52-8 46-7 43-7 47-5 51 -8
1939 1940 1941 1942 1943 1944 1945 1946 1947 1948
47-9 49-2 50-4 480 46-2 40-5 38-5 35-3 32-9 370
42-6 42-8 42-9 43-9 45-3 | 49-2 j 500 510 51-7 48-5
8-8 7-5 6-4 7-7 80 9-7 10-7 12-9 14 3 13-2
0-7 0-5 0-3 0-4 0-5 0-6 0-8 0-8 10 1-3
? ? ? ? ? ? ? ? 01 ?
1939 1940 1941 1942 1943 1944 1945 1946 1947
39-6 39-9 421 410 37-4 310 31 -8 290 26-8
44-2 45-7 440 44-4 46-2 48-8 , 46-9 470 i 47-6
141 12-8 12-5 131 14-6 17-9 18 6 ! 20-9 21 -8 j
20 1-5 1-3 1-4 1-7 21 2-5 2-8 3-5
01 01 01 01 01-l 0-2 0-2 0-3 0-3
i ; j I
390 35 3 35-5 37-5 410 43-9 44-6 49-9 51-5 47-4 43-7
3-2 2-3 1-8 20 2-3 2-5 2-5 3-3 4-7 4-9 4-3
._!_?
0-2 01 ? ? 01 01 01 01 01 # 0-2 0-2
l
Marriage (yrs)
4
? ? ? ? ? ? ? ? ? ? ? ?
is changing
very
recent
and
previously discussed. It is quite clear that the 1947 cohort has relatively high fertility. It is also clear that the 1948, 1949, and 1950 cohorts have succes sively fallen from this level. The latest information of
the
riage,
1947
1950. Here of
is at
cohort to
referable
4 years' in
fertility
of mar
duration calendar
the
year
the cohort has the lowest proportion
infertile
26-8
marriages:
cent,
per
against
42 1 per cent, at this duration for the lowest cohort, 1941.
The
1947 cohort
is, however,
only
2
2 per
cent,
lower than the 1946 cohort. The 1947 cohort has also the highest percentage of 2- and 3-child families at this duration.
The
are
proportion,
a very
small
3-child
families viz.,
3-5
at this duration against
2-5
per
5
5
43-8 441 42-8 44-8 45-1 44-7 42-2 41-9
18-6 18-7 17-1 191 21-2 23-6 24-2 26-4
3-7 3-2 2-7 30 3-9 4-5 4-9 5-4
0-4 0-4 0-3 0-4 0-4 0-6 0-6 10
? ? ? ? ? ? 01 ?
6
1939 1940 1941 1942 1943 1944 1945
29-4 29-8 30-4 261 260 240 25-7
40-6 41-6 41-8 42-7 410 401 37-7
230 22-8 22-3 24-9 25-7 27-7 27-6
5-9 4-9 4-7 5-3 6-2 6-8 7-4
10 0-8 0-7 0-9 10 1-3 1-3
01 01 01 01 01 01 0-3
? ? ? ? ? ? ?
1939 1940 1941 1942 1943 1944
26-5 24-6 25-7 23-4 240 22-4
38-8 38-7 38-8 38-9 36-6 36-4
24-9 27-9 26-9 28-3 28-8 29-9
7-8 7-1 7-0 7-6 8-5 8-8
1-6 1-4 1-3 1-5 1-7 21
0-3 0-3 0-3 0-3 0-4 0-4
01 ? ? ? ? ?
1939 1940 1941 1942 1943
23-6 21-3 23-7 21 -9 22-8
350 350 35-6 35-6 33-4
28-3 31 -6 29-2 29-9 30-3
100 9-4 90 9-8 10-2
2-3 2-2 1-9 21 2-5
0-6 0-4 0-6 0-7 0-8
0-2 01 ? ? ?
1939 1940 1941 1942
21-7 19-9 22-7 20-9
31-7 31-9 32-9 32-8
30-3 33-3 30-6 311
120 111 10-4 11 -3
31 2-9 2-5 2-8
0-9 0-7 0-9 11
0-3 0-2 ? ?
1939 1940 1941
20-8 , 191 220
29-5 29-5 30-6
30-9 341 31-4
13-2 12-5 11-6
3-9 3-5 31
1-2 0-9 1-3
0-5 0-4 ?
j i i
j I
12
over ~ ? ? ? ? ? _ ?
j
situation
disordered
4
33-5 33-6 37-1 32-7 29-4 26-6 280 25-3
8
slowly.
extremely
3
1939 1940 1941 1942 1943 1844 1945 1946
I
The form of Table VIII is useful to shed light on the
0
7
It is clear that by the end of 10 years the per centage
of Live Births by Present Marriage
Number Cohort '-? 6 and
! j
9
10
i
_l >_I_I_L_J_
cent, for 1945 and 2-8 per cent for 1946; but the percentage of 2-child families is high, although not
again
i.e.
cohort,
than
greater appreciably 21-8 20-9 against
for
per
cent.;
1946
the and
for
1-child families it is 47-6 against 47-0 per cent. It
is here
that
the
cohort
demonstrates system in fertility research. For
to prominence
its claim
is clear that the high rates of into
many
claiming
a
it
1947 which misled in
reversal
the
of
trend
fertility were largely due to a change in the incidence of
births
increase
within marriages in quantity. In
without so
far
as
substantial any the 1947 cohort
is at present of slightly higher fertility than the others, this This
is due
to an
tendency
in 2- and
increase
less
is, however,
3-child
outstanding
families. in
1950
than
previously. For cohorts
successively
1948, less
1949,
knowledge;
and but
we have 1950, each later cohort
COHORT ANALYSIS OF FERTILITY IN ENGLAND AND WALES, 1939-50 has successively lower fertility at each duration. At duration 3, the 1948 cohort is lower than the 1947 cohort for the two significant sizes (1- and 2-child families). At duration 2, the 1949 cohort has fewer 1-child
than
families the
However,
cohort
any previous cohort has
1949
a
since
1943. more
few
very
2-child families than other cohorts before 1947. It seems that there is a slight tendency for the 2-child family to be more popular, but this is not sufficient this
an
se
per
to of
average
achieve over
two
since
replacement, children per
for
completed
is necessary.
marriage
The 1950 cohort is well below its immediate predecessors and very little above the 1939 cohort, which, as we shall see later, is itself well below If we now replacement level at later durations. score
values
these
duration
to
according
size
relative
in each
(Table IX) it is clear that some of the war some
years
have
still
they
have
been
less
lost ground successful
to make
Registrar-General's
available, RELATIVE
these
the crude
The first
suggest.
figures
1941 cohort will are
values
parity
serve to pinpoint
almost
For
cohorts.
the
the
they exceed the 1939 and
calendar year 1946, when 1940
Its
this. until
least
always
second
one
it gains
parity
place (over 1939) in 1947, but is not here pre eminent. For the third parity it is always lowest. The same
can be seen pattern are aged 31-35 the cohorts
a further Fig. 5 sizes for the effect This
in the
1942
cohort.
10 years
after
Since
of marriage
increase in fertility is still possible. shows the proportions of different family one cohort (1939). We see clearly that of later age at marriage is to lower fertility. between
relationship
age
MARRIED 16-20
4?|
at
and
marriage
in the next section.
fertility is discussed
MARRIED21-25
up
later
years
are
iIl.
O I 2 OtLIVE NUMH*
3
illi
4 5 O OfI ?l?Ttrt 6 3 MKHI NUMiM llVt 2
4
5
6
MARRIED 31-35
MARRIED26-30
501
IX Table POSITION OF COHORTS (TABLE VIII VALUES) (Constant 12-point grading) Duration
of Marriage
(years)
OI234 MUMMR OfLevi
7 6 9
8 4 5 8 3 4 1125 1 6 10 4 10 12 10. 12 ? ? 12 ? ? ? ? ? ? ? ? ? ? ? ? ?
7 7 2 ? ? ? ? ? ? ?
9 9 10 10 12 12 12 12 11 10 8 8 8 6 5 3 5 4 3 1 4 3 1 ? ? 2 1 ? ? ? 1 ? ___
12 8 1
9 9 1
8-6 8-4 6-5 5-6 7-4 60 70 5-2 1-2 3-7 4-5 40
12 12 1 1 8 6 5 ? ? ?
9-6 6-8 10-3 7-4 5-9 4-0 4-4 2-8 1.3 1-5 3.0
12 ? ? ? ? ? ? ? ?
? ? ? ? ? ? ? ? ?
?
?
? ?
_ ?
1? 9 8 6 12 12 12 6 5? ? 1 ? ? ? ? ? ? ? ? ? ? _ _ ? ? _ __
4-5 8-8 120 8-4 5-3 40 3 0 2-3 1-5 i-o
III.
5 60I234 NUMlIt
(ItTHt
MARRIED36-40
1001
Parity ? 5 7 8 10 8 12 12 ? 91111 9 10 8 1 ? 12 12 12 12 12 10 9 ? 11 10 9 7 6 5 6 ?9 8 665 34 ? 7 6 5 4 1 1___ ? ? 7 4 5 3 3 ? ? 4 3 3 l______ ? 2 1 1 ___-_ ? ? ? ? ? 1 2 ? _ 3___________ ?667654 ? 9 ? 12 ? 11 ? 9 ? 7 ? 4 4 ? 2 ? l ?
-1L_
10
6789
First Parity 9 12 11 7 1939 8 12 11 10 1940 11 10 12 12 1941 1110 1942 893 7 6 8 9 1943 5 1 5 5 1944 3 8 4 5 1945 4 2 2 1946 6 1 1 1 2 1947 2 3 6 ? 1948 ? ? 6 3 1949 ? ? ? 1950 4
Third Parity 1939 ? 1940 ? 1941 ? 1942 ? 1943 ? 1944 ? 1945 ? 1946 __ 1947 ? 1948 ?
than
it may well be seen that the fall in the
Cohort-Average 12345
Second 1939 1940 1941 1942 1943 1944 1945 1946 1947 1948 1949
for
fertility of the 1951 and 1952 cohorts is even greater
Further
up.
in making
parities than first parity births. Thus the relatively high number of births in 1951 and 1952 may be due in part to postponed higher parities. When the Reviews
239
MARRIED41-45
OI234S6
OI23456 Fig. 5.?Family
size at end of 10 years' marriage, for 1939 cohorts.
(7) Age
In
56
OfUVC tlMTHI
at
the
1930s
demographers
who
Marriage
and
disagreement claimed
that
by age at marriage,
Fertility
existed
between
a partial
reversal
of the falling birth rate could be achieved by persuad women to marry ing enough of age claimed that a change
necessarily
and earlier, at marriage
change fertility habits.
those would
who not
The protagonist
240 WALLIS TAYLOR Table
X
LIVE BIRTH RATES CUMULATIVE (TOTAL BIRTHS) Older Age Groups compared with 16-20 Age Group at Marriage 1940
1939
Cohort. ..
..
Age Group
1 2 3 4 5 6 7 8 9 10
Duration of Marriage (yrs)
21-25
16-20 100 100 100 100 100 100 100 100 100 100
|
26-30
21-25
26-30
16-20
100 100 100 100 100 100 100 100 100 100
58-3 67-4 71-2 73-7 75-4 76-2 76-6 76-6 76-6 76-4
47-8 560 60-5 63-7 65-5 66-4 66-5 660 65-7 65-2
100 | 73-8 100 809 100 81-5 100 820 100 81 -7 100 81-4 100 81-4 ______ ? ? ; ? ? i
38-7 50-8 52-9 55-9 58-6 60-6 61 -7 62-2 62-4 62-2
49-9 620 64-4 67 1 69-3 71 1 720 72-7 73-2 73-1
19431945
16-20
\ 21-25
26-30
16-20
| 21-25
26-30
67-3 73-6 74-6 75-6 73-9 73-1 72-7
? ?
100 100 100 100 100
761 87-5 87-6 86-7 86-1 ? ?
66-5 79-9 78-5 77-2 76-3 ? ?
? ?
? ?
? ?
? ?
_ of
the first
was
part
the Registrar-General
(Statistics
AGE
for 1938, publ. 1944) and that of the second part Kuczynski (1942). The
issue
immediate with
a
has
which
a greater
induced younger
1939,
spinster marriage
at
to marry people common the most age
23.
It fell rapidly during
21.
This
means
a substan
that
are marrying at of women number tially greater This is of the age of 16-20. age group special is highest interest because married among fertility women and with to it. Ceteris paribus, assignable shift
downward an
involving married of
unchanged.
Similar those
group,
Per cent. of 16-20
Number
16-20 21-25 26-30 31-35 36-40 41-45
100 74-8 63-7 47-3 20-7 3-9
I 3-309 2-259 1-605 1006 0-436 0082
100 68-3 48-5 30-4 13-2 2-5
aged
fall
consistent to
relative
X
Table
increased.
the
21-25
the
there
fertility older age
now
compare at different
from fertility a they have therefore
those
compare
of
fertility is made
extrapolation. only
to expect groups greater because
expect if only
might
younger, married
life.
We
shall for
standardized
when
exact
ends, similar
possible by using XI and both Table
in toto but
of
of
fertility
knowledge A of marriage. at marriage by age
As
of
shall do this first at the
We
fertility is consistently not
One
fertility
length of marriage.
marriage
ages. married fecund
longer
our where point 10 years' duration
total
the
for the Fig.
viz.,
after
compari completed previous 6 show,
lower with higher marriage per
year
of fecund
marriage.
100 82 74 63 42 18
of
Views
Demographic
7 has in Section raised implica controversy and demo which call for comment. Biologists in the same do not use the term "fertility" graphers
judgment social agencies
states.
off
expresses to born age or
speaks ovum
in
the the
legitimate
of
fertility,
low
carries
know
a physiologist
When
he
is less, or that ovum fertilized
means
normal
of ages
the chances are
lower
that
specifically of for
the
within It
of the
is less frequent, that fertilizability
particular the other On incidence
of
merely children
that we
implication
circumstances.
to
different
or processes that fertility
accordingly.
in what
ovulation of
declines
groups
it no
with
physiological asserts
demographer in successive
quinquennia the statement (15^4-5), period of number the fact that the mean women a fixed number of married steadily
reproductive
these
and
the
When
falls
why
is
confusion Hence footnote). involves matters if interpretation relative the importance concerning
(see p. 226, unavoidable
almost
age groups the argu
led us
0114 0094 0084 0072 0048 0020
29 24 19 14 9 4
The
a
been
Per cent. Fer tility
Fertility
size has
has
in the younger whereas groups,
of
had the Registrar-General to remain situation unchanged.
married
age,
that
of
We
son
shows
and
(8) Biological
sense,
to the next youngest apply at marriage. This is next
remarks
2-106 1-574 1-341 0-995 0-436 0082
Fertility per Year
tions
groups remaining an increased total
in fertility and its proportionate
highest
ments
the result
should
of marriage age of 16-20 age group in the relationship
the other with group also It would signify
16-20
fertility.
in
increase
women
the
the mean
of
Length of
Marriage Number
due regard to the prevailing high level of nuptiality, a
Total Fertility Fecund
FERTILITY
at-Marriage in Per cent. Years of 16-20
of
was
is now
and
period circumstances
of
Live Births after 10 years' Duration of Marriage
Cohort Age Group
and
the
During external
deals,
proportion In
ages.
the war,
years.
post-war this study
the war
to
relevance
special
Table XI AND RELATIVE
AT MARRIAGE
survival reasons
in utero inherent
or attributable cycle reproductive as nutrition. such external agencies, to the referable any hand, figures live in
births a
to
community
married which
women practises
of
COHORT ANALYSIS OF FERTILITY IN ENGLAND AND WALES, 1939-50
241
100*4
J |
|
FERTILITY AT lOYEARS' OF MARRIAGE DURATION ESTIMATED TOTALFERTILITY
^^^M
68-3?/o
2o j
^^m
1'?-
I
I
r?
I L^JlI
oJ
L^Ll
16-20
L^lJ
Lz^J
26-30
21-25
LMsJfal
L^lI
31-35
36-40
41-45
AGE AT MARRIAGE Fig. 6.?Live are
limitation
to
open
family a different level. quite mores If the community prescribe it is evident level of family size, marry than which
births, by age at marriage. on
interpretation a certain
target who
that
women
will the attain younger target women Hence later. who marry duration do not take into account
level
earlier
no
figures
have
any incidence
of marriage the whether
on
bearing
presumptive of live births
women
married
among
at
to social pressures different ages is attributable or to the various mechanisms with which biologists customarily In the
associate two
extreme
life, it is plausible differences
the
term
to assume sense
in the broadest
ing differences are of no mean able
to delimit
able
to make
with
respect
importance; any age a definite
to but
the
genetic we are
about range of assertion
includ
term,
make-up, not in fact
which this
we sort.
are The
of any such assumption on
the
likelihood
has
a small
that
at marriage will have a uniquely to the without due consequence predictable regard in a community social in which pressures operative some measure of birth control is universal. social
Such
are
pressures
of
evidently
different
kinds at different social levels. Thus it is highly in the social groups likely that early marriages from which the professions largely recruit themselves will
encourage delay
smaller
reproductive
that physiological of
whatsoever bearing shift in the mean age
when
fertility. of groups
age
intrinsic plausibility no
vocation. pressures among outside to assume
as
motherhood of
marriage to a woman's
a whole-time
would
career a
accommodate
continuance in another family It is equally that different social obvious in the wage-earning operate community, women the home some
who when
customarily their older
responsibility
It is indeed safe to presume
work
undertake children
for care
of
are
able
the younger.
that the net effect of
242 WALLIS TAYLOR social pressures in different groups is different with respect both to the direction in which it affects fertility in the demographic sense of the term and to
the
to which
extent
a very have
that would means us
of
knowledge
the size of the completed
determining to
express or raising
any
about
opinion
of lowering two or three years by level in Britain.
the mean above
or
the agencies
family entitles
the
consequences age of marriage its present below
the
in view
has
in mean
increase
in
(5) The proportions
the
Nevertheless
the Registrar-General
by
not
been size
family 1938.
in the period are
recent
associated anticipated
of families of different sizes
are estimated 10 years of marriage to age at marriage for women married
after
Acknowledgments Professor Lancelot criticism.
indices computed
are misleading if the end of fertility under unstable
with
and Wales
Summary
(1) Fertility
to age of marriage. in age at marriage
related decrease
unlikely
of marriage it is by no
age
consequences,
our
that
is not
It
the mean
shift of big foreseeable
admissible
so.
it does
(4) Fertility, expressed as total fertility or as fertility per year of fecund married life, is inversely
according in England
1939-50. due
to Dr.
Enid
F.R.S.,
Hogben,
for
Charles
and
advice
and
from annual data is the
assessment
REFERENCES Barclay, R. S., and Kermack, W. O. (1937-8). Proc. roy. Soc. Edinb., 58,55. an alternative based method describes munication Charles, E. (1935). "Effect of Present Trends in Fertility and Mort women on sets of married and forth its cohorts ality." London and Cambridge Economic Series, Special Memo. No. 40, London. advantages. (1936). Proc. roy. Soc. Edinburgh, 56, 6. (1938-39). Trans, roy. Soc. Edinburgh, 59, 371 and 673. to is used show that the The method high (2) (1948). "The Changing Size of the Family in Canada." Census No. 1. Dominion Bureau of Statistics, Ottawa. Monograph were a to of rates of 1946-48 due birth complex Hajnal, J. (1947). Population Studies, 1, 137. to any causes in substantial increase unrelated Karmel, P. H. (1949). Economic Record, 25, Dec, No. 49, p. 83. Kermack, W. O., McKendrick, A. G., and McKinlay, P. L. (1934). fertility, and that fertility has indeed fallen annually Lancet., 1, 698. Kiser, C. V. (1952). /. Amer. statist. Ass., 47, 25. since that period. Kuczynski, R. R. (1942). "The New Population Statistics", National Institute of Economic and Social Research, Occasional Papers (3) An estimate of completed fertility is made No. 1, p. 25. Univ. Press, Cambridge. a new Royal Commission on Population (1950). Papers, vol. 2. "Reports is computed. index of fertility from which and Selected Papers of the Statistics Committee". H.M.S.O., The use of this index makes it possible to show that London. of England and Wales "Statistical Review (1944). Registrar-General in England and Wales fertility is now below replace for 1938", Tables, Part II Civil, p. 157. H.M.S.O., London. but Taylor, W. (1951). British Journal of Social Medicine, 5, 162. is not yet stable, ment level. Moreover fertility in the Whelpton, P. K. "Cohort Fertility: Native White Women is still falling. United States" (reviewed by Kiser, 1952). conditions.
This
com
Appendix
Technical Calculation
of Cohort
Legitimate
Age-Specific for
England
and Wales,
for the rates here All the material Annual in the Registrar-General's vols Civil Tables, 1938-50, are given in the form in which
is available computed Statistical Review, to tables and all reference they are therein designated.
for the rates comprises (1) The population at such a date that they are of the married the calendar stated year during marriage were If maternities tabulated the cohort. at present and not, as exclusively marriage,
spinsters of duration to attached by date of in England
since marriage, durations and Wales, 12-monthly by determined be unequivocally would these populations census of data In the absence duration. for each of marriage for all women age and duration recording can be derived from the appropriate only population the
record
solutions
of have
Several marriages. empirical previous been proposed by the Registrar-General
and new
Live
Birth
Rates
by Parity
1939-50 It can
others.
graphical incorrect and
however
technique a more exact
be shown that previous solution has
of a by means are formulae been found.
are from taken Tables Maternities (2) Legitimate and "II", adjustment "OO", "SS", being made "QQ", 1940 are tabulated for the fact that 1939 and by date of registration but not of occurrence. was made for incomplete data. For (3) Adjustment for 98 -6 per is complete the worst year, 1940, information for only 0-28 per cent. cent, and entirely absent (4) The ... 26-31, of married were clearly aged
21-25
21-25, 16-20, aged the first year during As such they cohorts. defined annually since, e.g. those by duration, in 1939 in the first year of marriage 1) (duration
groups, quinquennial to 46-50, at maternity life were used as basic
COHORT ANALYSIS OF FERTILITY IN ENGLAND AND WALES, 1939-50 LIVE
BIRTH
Table Appendix A RATES PER 1,000 MARRIED (1939 Cohort)
Duration Age Average in Cohort of Total 0 12 1939 Mar-. Age Accum. riage Yearly Yearly Accum.
16-20
21-25
26-30
31-35
36-40
WOMEN
Parity
Accum.
Yearly ? 2 12 34 47 53 49 53 49 36
Accum.
Yearly ? ? 0 3 9 18 19 25 28 25
?
1 2 3 4 5 6 7 8 9 10 11 12
465 283 230 209 181 179 144 182 154 118 115 105
465 748 978 1,187 1,368 1,547 1,691 1,873 2,027 2,145 2,260 2,365
458 | 458 660 202 88 748 56 804 36 840 25 865 19 884 20 904 10 914 6 920 __________!__ ____________
3 78 129 116 88 80 50 70 49 27
3 81 210 326 414 494 544 614 663 690
24 25 26 27 28 29 30 31 32 33 34
1 2 3 4 5 6 7 8 9 10 11 12
23 232 232 166 167 151 152 117 145 122 85 71 60
232 464 630 797 948 1,100 1,217 1,362 1,484 1,569 1,640 1,700
227 227 197 424 97 521 83 604 61 665 41 706 735 29 29 764 19 783 9 792 ____________ ____________
3 31 61 67 65 73 47 67 52 31
3 34 95 162 227 300 347 414 466 497
_______ 2 5 14 20 29 28 33 32 25
2 7 21 41 70 98 131 163 188
30 31 32 33 34 35 36 37 38 39
1 2 3 4 5 6 7 8 9 10 11 12
180 29 200 137 147 138 136 106 122 100 69 45 40
180 380 517 664 802 938 1,044 1,166 1,266 1,335 1,380 1,420
173 173 177 350 83 433 76 509 60 569 44 613 28 641 28 669 18 687 9 696 ____________ ____________
3 19 48 57 58 63 50 55 42 27
3 22 70 127 185 248 298 353 395 422
_______ 1 4 10 14 21 21 26 25 19
!______ 5 15 29 50 71 97 122 141
34 35 36 37 38 39 40 41 42 43 44
1 2 3 4 5 6 7 8 9 10 11 12
33 174 176 123 118 109 99 73 66 48 28 14 ?
174 350 473 591 700 799 872 938 986 1,014 1,028 1,028
163 163 150 313 71 384 52 436 42 478 28 506 18 524 15 539 10 549 4 553 ____________ ____'________
3 19 43 51 47 43 30 28 19 9
3 22 65 116 163 206 236 264 283 292
_______ 1 5 10 15 19 15 14 12 7
38 39 40 41 42 43 44 45 46 47
1 2 3 4 5 6 7 8 9 10
124 100 70 59 38 23 17 10 6 3
124 224 294 353 391 414 431 441 447 450
3 12 25 27 16 8 6 3 1 1
3 15 40 67 83 91 97 100 101 102
?
43 44 45 46
1 43 2 23 3 12 4 5 547 2 6 2 49 1 7 8 0
1 4 60 70 81 9 90 9_
?
41-45 48 50
113 82 39 24 13 6 5 3 1 0
113 195 234 258 271 277 282 285 286 286
43 38 66 17 78 9 83 2 085 87 0 88 0 88?66? 51 90 88?66? 0 52 10 88?66?
38 55 64 66 66 66 66
Separation
4
3 Yearly
18 19 20 21 22 23 24 25 26 27 28 29
28
243
9? 2 9_ 2
1 3 2 1 1 1 0
2 14 48 95 148 197 250 299 335
_
? ?
? 0 1 3 7 9 11 12 13
0 1 4 11 20 31 43 56
0 1 3 5 5 8 9 9
0 1 4 9 14 22 31 40
1 6 16 31 50 65 79 91 98
_____ 1 2 3 6 6 6 5 4
1 3 6 12 18 24 29 33
i 4 10 17 23 26 28 29 30
? _____ 1 1 1 2 2 1 0 1
? ? ?
5
Accum. ? ? ? ? 1 3 8 18 31 45
? ? ? 0 1 3 4 4 5
0 10 4 8 12 17
Yearly ? ? ? ? ? 0 1 2 4 6
? ? ? >?
Accum. ? ? ? ? ? 0 1 3 7 13
? ? ? ? 0 1 2 3 5
1 1 1 2
? ?
? ? 0 11 1 3 3 3
0
? ? ?
? ? ? 0 0 1 1 1
2 5 8 11
0 0 1 2 3
_
?
?
0
Yearly ? ? ? ? 1 2 5 10 13 14
_
1 3 6 7 6 3 2 1 I 1
?
Accum. J ? ? 0 3 12 30 49 74 102 127
______ !______ !______ !______ ? 2 2_ ? 2 ? 2
_ ? ?
? ? 1 2 3 5 7 9
1 1 1 2 2 2
?
? ? ? ? ?
? ? ? ? 1 1 1
?
?
?
^~
? ?
? ?
? ? ?
? ? ?
_ 1 2 3 5 7 8 8 9
? ? ? ? ? ?
1 2 2 3
?
1 0 1 0 0
? ? ? ? ? ?
into parities cannot be accurately made after 10 years' duration of marriage.
1 1 2 2 2 2
? ? ? ? ? ?
?
? ? ? ? ? ?
0 0 0 0
0 0 0 0 0
? ? ? ? ? ?
244 WALLIS TAYLOR became
22-26 in 1940 in the second year of marriage less easily are, as we have seen, (duration 2). They 21 and Those described in terms of marriage. aged of marriage less than 22 in 1939 in the first year's duration were married at the age of 20 or 21 in either 1938 or 1939. of the correct population this reason, the estimation For of num the estimation for each cohort made necessary To of the year. bers married by age for each quarter ? 1 term n < n the Registrar-General's aid typography ? n is herein duration 1, so that the first designated 0 < of married life year 1) is (Registrar-General's to as Year referred one were advanced Thus of marriage. aged
16-20,
17-21,
1. Each successive in age and one
year one
cohort
18-22,
19-23,
year year
in subsequent etc. 20-24,
the cohorts in duration years was
to the condensed form of the Registrar (5) Owing to compute it is not at present possible General's Tables, 10 years. the first after for durations accurate values
two earlier the for values therefore, Whilst, higher are are shown estimated in Fig. cohorts 4; the values not used in the analysis. to live rates were reduced (6) The maternity finally birth rates. The results for one cohort, 1939, are given in Appendix Table A. is in these involved labour (7) The computations to the condensed form of the Registrar related 10 years of If durations of over Tables. were and separate tabulated by single years, marriage parities given by single years of age, the value of the Tables of the enhanced. It is a measure would be immensely mores Tables of that the Registrar-General's English of Mortality the Tables 36 pages, whereas occupy Fertility is more the community about 300. Presumably occupy are dying of Inter to learn that fewer females interested
directly General's
national whether
List Classification the community
than to know 162 ("Old Age") itself. is or is not replacing
