Below are the first 10 and last 10 pages of uncorrected machine-read text (when available) of this chapter, followed by the top 30 algorithmically extracted key phrases from the chapter as a whole.
Intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text on the opening pages of each chapter.
Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.
Do not use for reproduction, copying, pasting, or reading; exclusively for search engines.
OCR for page 31
31
mere should be a weak positive relationship between socioeconomic
status and later fertility in traditional settings. This hypothesis
derives from the positive health effects implied by relatively advantaged
social positions. Husband characteristics may prove vital in measuring
family well-being (B11 16, B12,16 > 0), especially nutritional levels and
overall health. Healthy women are more fecund. AFB may also reflect
social standing (63,16 < 0), as argued earlier. However, there is no
basis for positing a curvilinear relationship between AFB and LF in
traditional societies; hence in these settings, we would set 816,16 = 0.
Because of their correlations with health and fecundity, respondent char-
acteristics should also affect LF (~l,16, 82,16, 89,16, 610,16 > 0).
Each individual relationship should be weak both because there are so
many, and because they imperfectly approximate the underlying, unmeasured
variables.
1 .4 REDUCED AND SE==DUCED FOR IMPLICATIONS OF THE MODEL
His section discusses some implications of the model, first explaining
why its complexity needs to be reduced. Next, certain implications of
the model for three familiar variables--children ever born, contraceptive
use, and infant and child mortality--are traced. This leads to develop-
ment of implied and actual semireduced form equations for these
variables, followed by a discussion of inferences that can be drawn about
the coefficient signs in these equations.
The Need for Reduction
As shown above, the threefold distinction between onset, early fertility,
and later fertility permits development of an intricate and comprehensive
micro model embodying a number of untested hypotheses. This micro model
is not the total model, which would also incorporate macro variables to
explain coefficient variability across settings. We intend to continue
the theoretical development of the model begun in this paper elsewhere.
Our present focus is on testing the implications of the micro model. As
a starting point, Table 1.2 presented the predicted signs of the
structural coefficients in traditional and transitional settings implied
by the micro model.
How is the model to be tested? Its estimation for a single country
would permit one kind of test. In particular, where we have hypothesized
that a coefficient should have a positive sign in all settings, the
hypothesis could be rejected empirically if the sign were found to be in
the opposite direction. However, this would be a weak test. Among other
things, it applies only to those coefficients for which a single sign was
hypothesized. How can hypotheses be tested which relate to coefficients
for which sign variation across settings is possible? There will be
variation not only in the sign, but also in the magnitudes of the
coefficients. His variability is theoretically admissible and is
implicitly assumed to exist in the above discussion, since for a
coefficient to Travels from negative to positive, it must take on a
OCR for page 32
32
range of values. More strongly, the magnitudes of the coefficients
should increase or decrease as a function of the "distance. from various
ideal-typic anchor points of the traditional/transitional continuum.
Because the model postulates contextual variability in a large
proportion of the micro structural coefficients, its testing must involve
estimation of its micro and macro components. If the empirical reali-
zation of the model is precisely as summarized in the preceding sections,
there w~11 be 99 micro structural coefficients. Of these, some 60 are
hypothesized to vary in sign as well as magnitude. Although others can
vary similarly, we cannot specify the nature of their variability as a
function of traditional/transitional setting differences. Hence, at the
macro level there is a set of at least 60 potential structural equations,
one for each micro coefficient of interest. Suppose that this set is
estimable (i.e. Of does not encounter the problem of negative degrees of
freedom), as will be the case if the micro-macro model is envisioned as
consisting of a set of equations that includes micro regressors and macro
regressors, and interactions between them. We then have the practical
problem of data exploration which accompanies theory development for each
of the 60 macro equations. Of course, equations will not be conceptually
independent since they involve the same underlying hypotheses. Neverthe-
less, a great deal of complexity must be entertained, especially during
the data exploration stage. It would be helpful if this complexity could
be reduced, even if that reduction were unnecessary for testing the model
To do this we examine the model to determine if it contains implica-
tions that can be tested directly in a simple way. Although the results
of this examination, described below, will be mixed, the process itself
proves enlightening.
Connections With and Between Familiar Variables
Some of the implications explored below relate to equations for children
ever born (CEB) and infant and child mortality (CM). m ese two variables
are commonly used in analyses of survey data and have broad theoretical
appeal because they are appropriate "counts variables for cohorts whose
fertility is complete. Although they do not appear explicitly in the
structure' equations of the micro model, they are present implicitly,
since CEB = EF + LF and CM = ECM + LCM; thus equations (1.4) and (1.16)
for fertility, and (1.3) and (1.14) for child mortality, sum to equations
for CEB and CM, respectively.
m ese summed equations are not structural because there is literally
no structure for which they are meaningful, given that equations (1.1) to
(1.16) state the causal ordering of the variables in the micro model.
However, there is no reason why we cannot consider whether the model
allows determinate predictions about the signs of their coefficients. If
so, a degree of simplification will have been achieved, and at the same
time, we will have related the model to CEB and CM. It will then be
meaningful to treat CEB and CM as response variables that depend on
variables actually In the model. This simplification would be lost if
the model did not allow determinate predictions since there would then be
no good theoretical reason to expect either positive or negative
OCR for page 33
33
relationships between CEB and CM and the variables actually in the model.
In spite of this simplification, however, still further reduction
would be desirable. A number of predetermined variables are clearly
secondary, for example, NMAR, DUR, and FEC. Of much greater interest,
for practical as well as theoretical reasons, are the socioeconomic
variables. It is primarily, but not exclusively, through these variables
that changes in the social system are transmitted. Moreover, these
variables define social positions. It is of some interest to describe
how a process is endogenously related to itself, as in the connection
between early and later fertility; however, only two of the structural
equations for reproductive process variables--those of boy and girl
Buff iciency--exclude socioeconomic predictors. In addition, we have
hypothesized that when the fertility process variables interact with
other variables in the determination of later fertility outcomes, these
interactions are always with socioeconomic variables. Examination of the
relationships between the socioeconomic and reproductive process variables
that follows below, requires reduction of the structural equations to a
simpler form. Children ever born (CEB) and child mortality (CM) are not,
of course, the only endogenous variables of interest. The variable for
contraceptive use patterns (LCU) is also crucial. The following
subsection formulates a model for examining hypotheses about the
relationships between socioeconomic position and CEB, CM, and LCU.
Implied and Actual semireduced Form Equations
To study the implications of the micro model for the relationships
between socioeconomic position and CEB, CM, and LCU, we obtain actual and
implied semireduced form equations from the structural equations by a
process of substitution to remove endogenous variables from the lists of
predictors. These semireduced form equations are something between
structural and reduced-form equations. Those of interest here exclude as
predictors all but the socioeconomic variables, some of which are endog-
enous in the total structural equations model. We term the semireduced
form equations for CEB and CM n implied" semireduced form equations. To
obtain this for CEB, we carry out the usual substitution process for EF
and LF, stopping whenever the variable involved is socioeconomic. mis
yields two actual semireduced form equations, one for EF and one for OF,
whose sum is the implied semireduced form equation for CEB. A similar
process yields the implied semireduced form equation for CM. The
semireduced form equation for LCU is obtained by substitution, but for
this variable there is no need to sum across equations; direct substitu-
tion into a single equation suffices. For this reason, we label the
expression that relates LCU to the socioeconomic variables the "actual"
semireduced form equation.
m e caution noted earlier for the sums of structural equations
applies here. The implied semireduced form equations are not part of the
equation system. m eir relevance Is simply that, given the model, they
permit consideration of the semireduced form implications of the
socioeconomic variables for CEB and CM. The three semireduced form
equations are as follows:
OCR for page 34
34
11.17) CM a0,17 + al,l7RESC + a2,1tWED + as ltWBM
+ ad 17RES + ~5,1}WSM + ~6,l7HED + ~7,17HOCC.
) LCU a0,18 + a1,18RESC + ~2,1§wED + ~3 1§WBM + Ad 1§RES
+ as, 1~SM + a6,1~ED + a7,1dHOCC + ~8,18(RESC)
~ a9 16RESC*WED + ~1o~l8(WED) + all,l8WED WBM
+ a12'l8REsC HOCC ~ a:3,l§WED*HOCC + a14,1§WBM*HOCC.
( ) CEB ~0,19 + al,lgREsc + ~2,1}WED + ~3 19WBM + ~4 l9RES
+ as 1§WSM + a6 lgHED + a7,l9HOCC + a8,19(RESC)
+ As 1gRESC*WED + alo~lgtWED) + all,l9WED WBM
+ a12,1,RESC*HOCC ~ a13,1~WED*HOCC + al4,l}WBM*HOCC.
It is immediately clear that although the equation for CM is linear
and additive, those for LCU and CEB are not. Equations ~1.18) and ~1.19)
contain quadratic terms in the two ultimate exogenous variables (RESC and
WED), as well as a number of product terms. These terms occur because of
several hypotheses associated with the structural equations: 1) an
extreme age at first birth (young or old) dampens contraceptive use and
increases later fertility among older cohorts of women; 2) the positive
effect of high early fertility on later contraceptive use, and the
negative effect of high early fertility on later fertility, are both
enhanced by greater than average respondent education; 3) the positive
effect of high early fertility on later contraceptive use, and the
corresponding negative effect of high early fertility on later fertility,
are both enhanced by the degree of modernity of husband's occupation; and
4) the effects of boy sufficiency on subsequent fertility and contra-
ceptive use may vary with socioeconomic status.
Because of the nonlinearities and interactions in equations (1. 18)
and (1. 19), the actual and implied semireduced form effects of RESC, WED,
WBM, and HOCC cannot be read directly from the equations. Instead, first
partial derivatives must be evaluated. These partials have the same form
for the LOU and CEB equations, and we present them below only for LCU.
In so doing, we assume that RESC is continuous; as we defined it
operationally, it is not, although conceptually there is every reason to
treat it so:
aLCU/aRESC = ~: :8 + 2a~,~RESC + OWED + a,2,:8HOCC
LCU/ WED a2,~8 + OWED + ~9,~8RESC + a::,~8WBM + am :8HOCC
aLCO/aWBM ~ ~3,18 + ~11,18WE~
aLCU/aHOCC = ~7~18 + al2,18RESC + al3,1gWED + al4,l8wBM
OCR for page 35
35
As these derivatives show, the effects of RESC, WED, WBM, and HOCC depend
on each other to different degrees .
Thus far, we have discussed functional form without mention of a
country's location on the traditional/transitional continuum, which has
implications for the functional forms of the LOU and CEB equations. For
the LOU equation, there should be no semireduced form socioeconomic
effects in ideal-typic traditional settings. In ideal-typic transitional
settings, on the other hand, all of the effects hypothesized should be
found. For the CEB equation, there should be no interactions and no
nonlinearities in a traditional setting. In transitional settings, all
hypothesized interactions and nonlinearities should be present. The
basis of these expectations will be made explicit in the next subsection.
Since ideal-typ~c societies cannot be observed, data for a given
country can always deviate somewhat from expectations without necessarily
disconfirming an underlying hypothesis. This might be summarized as
follows: where interactions have been posited, the likelihood that those
interactions actually exist should increase as the degree of transition-
ality increases, and decrease later as all socioeconomic groups come to
participate in the fertility decline.
The derivation of equations (1.17), {1.18), and (l.l9) provides the
initial implications of the model, which concern functional form. First,
the child mortality equation should be a linear and additive function of
the designated socioeconomic variables. In the modeling of child
mortality as a function of designated socioeconomic variables, replicated
demonstration of nonlinearities (in the sense of sign reversals over the
range of a predetermined variable) and interactions would constitute
evidence against the model. The second implication is that the functional
forms for the contraceptive use and children ever born equations involve
specific nonlinearities (in the sense of sign reversals over the range of
a predetermined variable) and interactions, depending on a society's
position on the traditional/transitional continuum and other macro
variables. Empirical failure to detect these interactions as a function
of context and other macro influences would constitute evidence against
the model. The anticipated departures from linearity and additivity are
unusual and would probably not be hypothesized and similarly justified in
direct, single-equation modeling of the effects of the socioeconomic
variables. Chidambar~m and Mastropoalo {1982), for example, specify a
linear and additive single-equation model of contraceptive use. The work
of Cochrane (1979), to take another example, includes the hypothesis of a
nonlinear effect of education on fertility, but for reasons which differ
considerably from ours. Moreover, Cochrane's model does not imply the
existence of interactions between respondent's education and other
socioeconomic characteristics.
Expectations of variability in functional form by setting are bound
up with those for the structural coefficients summarized in Table 1.2, as
well as those about the linear combinations of these coefficients that
comprise the actual and implied semireduced form coefficients of equations
(1.17), (1.18), and (1.19~. In the next subsection, these anticipations
are discussed in summary form. This will clarify hypotheses about the
variability of functional form by context, and it will also indicate
whether it is possible to derive implications about the directions of
OCR for page 36
36
coeff icients. Put another way, the discussion of functional form involves
hypotheses about which coefficients are zero, and the discussion of
d irection of association is contingent on knowing which coeff icients will
be assumed nonzero. It is thus convenient to discuss both aspects of
coef f icient variability together.
Inferences About Coeff iciest Signs
A number of additional assumptions or hypotheses are necessary if
inferences about the signs of the coefficients in the implied and actual
semireduced form equations are to be made. This Is clear from structural
equations (1.11) to (1.16), which include coefficients whose signs, as
suggested, will vary across populations in a way that is essentially
orthogonal to the traditional/transitional continuum. In addition,
derivation of coefficient signs in the implied and actual semireduced
form equations requires assumptions about the intercepts for structural
equations (~.1) and (1.3) to (1.6~. These were not discussed earlier for
the sake of simplicity in exposition of the structural equations model.
To facilitate the development of inferences about reduced-form coefficient
signs, the discussion below reviews hypotheses about structural equation
intercepts, and then the complex issue of variability in the structural
coefficients orthogonal to the traditional/transitional continuum.
The intercepts for equations (1.1) and (1.3) to (1.6) are constitu-
ents of some of the semireduced form coefficients. For equations (1.1),
(1.3), and (1.4), we hypothesize positive intercepts. In fact, if the
empirical analysis yields negative intercept estimates after AFB is
transformed by subtracting its minimum, the specification of these
equations will be in question because the response variables (AFB, EF,
and ECM) are nonnegative and because zero values for the predetermined
variables are meaningful. We expect the intercepts of equations (1.5)
and (1.6) to be zero; no births and no child deaths should correspond to
zero values on the boy and girl sufficiency variables.
On the issue of coefficient variability (unrelated to the
trad~tional/transitional continuum) , and considering equation (1.13)
first, we will assume that AFB is inversely related to self-reported
fecundability (FEC). As noted earlier, this coefficient could also be
positive or zero. The assumption made here is a best guess about the
most likely effect of AFB on EEC.
The coefficients of equations (1.11) and (1.12) are more problematic.
There are reasons for positive, negative, or no SES effects on exposure
between age 30 and the time of the survey, likewise for the effect of
AFB. Moreover, as already suggested, there is no reason why this
variability should be associated with the traditional/transitional
continuum. We have therefore made an educated guess about the SES and
AFB effects. In particular, the results presented below are derived
under the assumption that the SES variables are positively related to
marital stability (81,11, 62,11, 64,11, 0~,
and that.marital stability does not depend on AFB (03,11 = 83,12 = 0)
The reasons for this choice of assumptions are not important. Having
derived the semireduced form implications of the model with any g iven set
OCR for page 37
37
of assumptions, it is then possible to return to the exercise using
different assumptions. When we in fact did this, the alternative
assumptions used did not meaningfully change the conclusions reported
below.
We consider next the impact of boy and girl sufficiency on later
child mortality, contraceptive use patterns, and later fertility, taking
the coefficients one equation at a time, with the following assumptions:
Child Mortality
a) 67,14 = 88,14 = 0;
b) 87,14 < 0; 68,14 < 0;
c) 67,14 > 0; 08,14 > 0
Assumption a) states that there is no effect of boy or girl sufficiency
on later child mortality, assumption b) states that the effect is
negative, and assumption c) states that it is positive. Clearly, any of
these alternatives is possible, and it is uncertain whether one outcome
is more likely than the others. Originally, we expected positive boy and
girl sufficiency effects on child mortality. However, there are routes
by which the opposite conclusion can be reached. Actually, it turns out
not to matter which assumption is used because they all lead to basically
the same inferences
This point almost, but not quite, holds for the contraceptive use
pattern and later fertility equations. Since these two equations are so
similar, we will treat them as a pair, making the following alternative
assumptions:
LCU
d) 67~15 = 0; 08,15 = 0; 619,15 = 0; t320,15 = 0;
e) 67,15 > 0; 68J15 ~ 0; 019rl5 = 0; 620115 0;
f) 67,15 > 0; f38~15 > 0; 8~15 > 0; 820~15 > 0;
g) 67,15 > 0; 638,15 > 0; 6319,15 < 0; 6320Ji5 < 0;
CEB
h)
i)
i)
k)
67,16 = 0; 68,16 = 0; 619,16 = 0; 620,16 = 0;
67,16 ~ 0; 68,16 < 0; 619,16 = 0; 620,16 = 0;
87,16 < 0; 88,16 < 0; 819,16 < 0; 020,16 < 0;
67,16 0, 820,16 ~ 0.
OCR for page 38
38
Assumptions d) and h) state that there are no boy or girl sufficiency
effects on contraceptive use pattern and children ever born. Assumptions
e) and i) state that the effects are additive, and that sufficiency
results in an increased likelihood of contracepting, as well as lower
later fertility. Although opposite assumptions could be made, they would
be implausible given the manifest content of the SCG and SCB variables.
Assumptions f) and j) assume interactive effects of SCG and SCB with
socioeconomic factors. We expect the impact of boy and girl sufficiency
to be stronger for higher- than for lower-status families. Finally,
assumptions g) and k) assume the presence of interactions that work in
the opposite way: increasing status diminishes the effects of boy and
girl sufficiency. We think the counteracting interactions to be
empirically unlikely and have included them for the sake of complete-
ness. All of these alternatives hold only for transitional settings.
The alternative assumptions for the LCU and CEB equations can be
considered independently from each other and from the CM equation. To
again state the conclusion before discussing the results in detail,
assumptions d), e), f), h), i), and j) lead to the same conclusions about
the semireduced form LOU and CEB equations. Assumptions g) and k), which
include the unlikely interactions, lead to different conclusions for
those equations.
All of our conclusions about the implied and actual semireduced form
effects of the socioeconomic variables on child mortality, contraceptive
use, and children ever born are summarized in Table 1.3. The remaining
discussion in this section explains how the conclusions reported in Table
1.3 have been reached.
To make inferences about the coefficients of equations (1.17) to
(1.19), it is necessary to examine the product strings of structural
coefficients that comprise each semireduced form coefficient. These
product strings are not presented here, since they are very long. To
reach the tentative conclusions summarized in Table 1.3, we determined
the likely sign of each semireduced form coefficient by inspecting the
pattern of signs in the product strings of structural coefficients that
comprise the semireduced form coefficient. This determination inevitably
involves expectations about the relative magnitudes of terms in a string
when not all terms have the same sign. Since an actual numerical outcome
will not be known until the full model has been estimated or simulated,
we have assumed for present purposes that if the great majority of terms
comprising a semireduced form coefficient have the same sign, that
coefficient is likely to have that sign, especially if the terms in the
minority are mostly those due to adjustment effects (e.g., those
associated with FEC, NMAR, and OUR). If, however, the signs of the terms
are about equally distributed, we have assumed that no inference about
the sign of the semireduced form coefficient is justified. A simple
illustration may help to clarify this process.
The implied semireduced form equation for CEB is the sum of the
actual semireduced form equations for EF and LF. The procedure described
above can be illustrated through examination of the actual semireduced
form equation for EF. To obtain this equation, we substitute structural
equation (1.1) into structural equation (1.4), yielding the following:
OCR for page 39
39
TABLE 1.3 Derived Signs of Implied and Actual Semi-Reduced Form
Socioeconomic Effects on Child Mortality, Contraceptive Use Pattern and
Children Ever Born, by Settinga
Contraceptive Children
Child Mortality Use Pattern Ever Born
Socioeconomic
Variables Trad. Trans. Trad. Trans. Trad. Trans.
Part A. Derived Signs Based on Assumptions a,b,d,e,f,h,i,j~
RESC ?
WED ?
WBM
RES
WSM
RED
HOCC
Part B. Derived Signs Based on Assumptions c,g,kb
RESC ? ?
WED
WBM
RES
WSM
HED
HOCC
? ?
Effects whose signs can be deduced are indicated by the symbol denoting implication.
Effects whose signs are inferred are indicated by the absence of this symbol. Effects
whose signs cannot be inferred are denoted by a question mark. Effects which are
necessarily zero because the variables are undefined for a particular setting are
indicated by an axe.
Alternative assumptions about the effects of sex preference are labeled as
follows:
CM
a.
b.
c.
LOU
¢7,14 = 0; ¢8,14 = 0
¢7,14 < 0; h8,14 < 0
h7,14 ~ 0; h8,14 > 0
d ¢7,15 = 0; ¢8,15 = 0; ¢19,15 = 0; 820,15 0
e. b7,15 ~ 0; ¢8,15 > 0; d19,15 = 0; 620,15 = 0
f ¢7,15 > 0; ¢8,15 > 0; ¢19,15 > 0; ¢20 15 ~ 0
g b7,15 > 0; ¢8,15 > 0; Petals < 0; 620 15 < 0
CEB
h ¢7,16 = 0; b8,16 = 0; ¢19,26 = 0; ¢2G,16 = 0
¢7,16~< 0; ¢8,16 < 0; ¢19,26 = 0; 020,16 = 0
~ t7,16 < 0; b8,16 < 0; b1g~l6 < 0; 620,16 < 0
k ~7,16 < 0; 68,16 < 0; b19,16 ~ 0; 520,16 ~ 0
OCR for page 40
40
EF = (80,4 + 63,400,1) + (81,4 + 03,481,1)RESC
+ (82,4 + 63,482,1)WED + 64,4WBM
= aO,4 + al,4RESC + CX2,4WED + a3~4WBM.
Next, consider the semireduced form coefficient for RESC, which is
l 4 = 51~4 ~ 63,461,1. ~0r~ng few the hypothesized signs in Table
1.], we would expect a sign pattern of (+, +) in an ideal-typic
traditional setting (since ~l'4 > 0 and 63~481,1 > 0) and a sign pattern
of (+, -) in an ideal-typic transitional setting (since 61,4 > 0 and
63,401 1 < 0~. Thus, given the structural equation hypotheses, the
semiretuced form sign of RESC is implied to be positive in traditional
settings, while there is no sign implication for transitional settings.
Moreover, it would be useless even to make an inference about the sign in
transitional settings, since we hypothesize that 61~4 > 0 and 63,401,1
< 0. Of course, we could hypothesize relative magnitudes of these
two constituents to resolve the ambiguity. Although we will do so on
occasion, such hypotheses must be used sparingly if the overall exercise
of sign inference is to be of general interest.
Given this procedure for making inferences about the likely signs of
the socioeconomic variables, the following discussion focuses on Table
1.3. me three equations are considered separately, first for traditional
settings, and then for transitional settings.
Child Mortali by tCM)
Considering first the equation for child mortality in traditional
settings, note first that there are no entries in Table 1.2 for WBM and
WSM because in ideal-typic traditional settings, these variables are not
defined. Observe next that the effects of current residence (RES) r
husband's education (HED), and husband's occupation (HOCC) are implied to
be negative. This implication holds because only a single structural
coefficient is involved in each instance. The implied semireduced form
effects of childhood residence (RESC) and respondent education (WED) are
ambiguous. The direct effects of RESC and WED on ECM and LCM are negative
(see Table 1.2), as are indirect effects through AFB, NMAR, and ECM.
These are offset by positive indirect effects through EF and FEC. It is
therefore uncertain whether the implied semireduced form effects of RESC
and WED will be positive, zero, or negative. This conclusion is not
sensitive to assumptions made about the effects of sex composition, as
can be seen in the comparison of panels A and B of Table 1.3. It results
from structuring the model to include intermediate outcomes, and probably
could not be reached otherwise.
The implied semireduced form coeff icients for child mortality in
transitional settings share certain similarities with those for tradi-
tional settings. In particular, the coefficients for RES, WSM, HED, and
HOCC are implied to be negative. This is so because only a single
structural coef f icient is involved in each instance.
OCR for page 41
41
The coefficients for RESC, WED, and WBM are ambiguous in transi-
tional settings. If sex sufficiency has no effect on LCM, or if the
effect is such that achieving a sufficiency of boys and girls decreases
LCM, then the coefficients are likely to be negative. Most terms in the
compounds that comprise the implied semireduced form coefficient. for
RESC, WED, and WHIM are negative. A few positive terms are present
because we hypothesize that RESOf WED, and WBM enhance FEC and EF (see
Table 1.2), and should thus have posit zve indirect effects on overall
child mortality. In addition, we hypothesize pQS\tiYO relationships
between AFB and RESC and WED, implying younger families later on and the
possibility of higher LCM. However, since these indirect effects are
likely to be minor, the effects of RESC, WED, and WBM will probably be
negative. If, on the other hand, a sufficiency of boys and girls
increases LCM, the expected signs of the implied semireduced form
coefficients for RESC, WED, and WBM are indeterminate; many of the
indirect effects of RESC, WED, and WBM on boy and girl sufficiency are
positive and translate into positive indirect effects on child mortality,
counterbalancing their negative effects via other routes. Panel B of
Table 1.3 displays the consequences of this alternative assumption for
semireduced form inferences. Without prior knowledge, it is uncertain
whether the semireduced form effects of RESC, WED, and WBM are positive,
zero, or negative in transitional settings.
To summarize the implied semireduced form effects of the socio-
economic variables on child mortality in traditional and transitional
contexts, out of twelve coefficients, seven have implied signs, two are
indeterminate as to sign regardless of sex sufficiency effects, and three
are determinate given prior knowledge of particular forms of those
effects. Although this may at first seem to be very little result for
the effort, the outcome is actually quite helpful. It shows that, given
our model, there is no theoretical basis for expecting interpretable
coefficient variability in the implied semireduced form socioeconomic
effects across the traditional/transitional continuum. In other words,
we conclude from this analysis that, since settings differ in their
levels of child mortality, it is important to analyze variability in
intercepts. For RES, BED, and HOCC, we have deduced that the effects
should be negative at both extremes of the traditional/transitiona'
continuum. The effect of WSM must also be negative where this negative
is defined. AS for RESC and WED, we cannot deduce or even infer that
their effects will "travel" from positive to negative as we move across
the traditional/transitional continuum. A similar point holds for WBM,
although it is not defined at the extreme of the traditional end of the
continuum. It appears that the implied semireduced form equations will
not differ meaningfully in their structural coefficients, but rather in
their intercepts; this is consistent with an additive rather than an
interactive analysis-of-covariance model with countries as the basis of
classification and the socioeconomic variables as covar~ates. This is
the fourth major implication in the present reduction exercise.
OCR for page 42
42
ontracePtive Use (LCU)
For those variables defined in traditional settings, the semireduced form
socioeconomic effects on LCU are all zero. mis follows from the
hypothesized zeros for the structural coefficients of equation (1.15~.
The inferences concerning transitional settings are more complex.
Equation (~l 5} contains hypothesized interactions and a nonlinearity;
the result is a semireduced form equation also containing interactions
and nonlinearities, different from those in the structural equation.
There is further complexity here because the inferred sign of some product
strings depends on assumptions about the effect of the interaction between
boy Buff iciency (SCB) and HOCC and WED in the structural equation. As
mentioned earlier, four scenarios can be constructed from reasonable
alternative assumptions about the direct and interactive effects of sex
composition (assumptions d) to gig. Three yield similar conclusions,
shown in Table 1.3, Part A. The fourth, based on the assumption that SCB
in combination with high socioeconomic status dampens contraceptive use
and increases later fertility, weakens considerably the conclusions drawn
about semireduced form effects of RESC, WED, and WBM, as shown in Table
1.3, Part B. This latter scenario seems the least likely of the four to
occur empirically. me three scenarios that lead to the conclusions
summarized in Table 1.3, Part A are as follows: sex composition is a
matter of indifference; boy and girl sufficiency have positive additive
effects on LCU and negative additive effects on LF; and the interaction
of SCB and SES enhances LCU and reduces LF. Considering first those
variables which do not interact in the semireduced form equation, the
semireduced form effects of RES, WSM, and HED are unambiguously positive
in transitional settings under these three sets of assumptions. Among
those var tables whose semireduced form effects are interactive, the ef feet
of WBM is also unambiguously positive. The effects of the remaining
interactive variables (RESC, WED, and HOCC) in the semireduced form are
not directly deducible, but are probably positive. In the unlikely event
that the fourth scenario prevails, the semireduced form effects of RESC,
WED, IBM, and HOCC become ambiguous , although conclusions about HED, WSM,
and RES are unchanged.
In general, the structural hypotheses summarized in Table 1.3 lead
to the expectation that the effects of socioeconomic variables on LCU are
positive in most cultures, and become larger In value the higher the
socioeconomic status. m e principal sources of ambiguity in the analysis
of signs of product strings are that AFB contributes expected negative
values to various components of the strings as well as the culture-
specific effect of sex composition. Late onset decreases the probability
of subsequent contraceptive use both directly, because of the nature of
the hypothesized curvilinear relationship between AFB and LCU, and
indirectly, by decreasing early fertility and thereby reducing the
incentive to contracept. It is expected that, as societies move toward
the transitional end of the traditional/transitional continuum, these
negative effects should become attenuated relative to the socioeconomic
effects. This expectation provides the basis for the inference (but not
the deduction) that the partials for RESC, WED, and HOCC will be positive
in most transitional settings.
OCR for page 43
43
Combining these results, the semireduced form effects of socioeco-
nomic position on LCU should be zero in traditional settings and should
be positive, either by deduction, reasonable assumption, or plausible
inference, in transitional settings. An additional result is that in
transitional settings, the semireduced form effects of some of the socio-
economic variables are interactive, with those interactions reinforcing
the positive socioeconomic effects in most cases. Because the progression
is from zero to positive c~effzeients with movement from the traditional
to the transitional end of the continuum, we conclude that with actual
data, there should be stronger positive socioeconomic effects the more
transitional the context; this is the fifth major conclusion of the
reduction exercise.
Children Ever Born (CEB)
The implied semireduced form equation for CEB in traditional settings
turns out to be much simpler than indicated by equation (1.19}, which
states the equation without respect to context. Because the structural
equation for later fertility (equation (1.16)) contains no hypothesized
nonlinearities or interactions in traditional settings, it follows that
the implied semireduced form equation for CEB contains none as well.
This equation is thus additive, with all of its effects implied to be
positive, if present.
The implied semireduced form equation for CEB in transitional
settings contains interactions and nonlinearities, as shown above. The
three socioeconomic variables not involved in these interactions and
nonlinearities (RES, WSM, and HED) have necessarily negative effects,
given their hypothesized structural effects. For no other variables are
the signs of the coefficients deducible. The effects of sex preference
under one set of assumptions preclude inferences about the semireduced
form effects of the remaining socioeconomic variables (Table 1.3, Part
B). However, inferences can be derived under any one of the other three
sets of assumptions tTable 1.3, Part A). The direct effects of RESC,
WED, WBM, and HOCC have all been hypothesized to be negative. Although
the effects of onset work in the opposite direction, the logic applied at
a corresponding point in the discussion of LCU has equal force here: as
the use of contraception becomes more widespread in a society, the effects
of AFB should lessen. If this view is correct, the implied semireduced
form effects of RESC, WED, WBM, and HOCC in most cultures should become
larger in the negative direction as location on the traditional/
transitional continuum shifts toward increased contraception.
The results for CEB thus lead to the following implications and
inferences concerning the semireduced form model: 1) there should be an
inverse relationship between so~zoeconomic effects and degree of transi-
tionality such that in most cultures' a shift from traditional to
transitional setting is associated with weakening positive and growing
negative effects; 2) the more this shift involves the differential
participation of social groups, the more likely there are to be non-
linearities and interactions in the semireduced form socioeconomic
effect; 3) in the unlikely event that intrasocietal cultural differences
OCR for page 44
44
are such that the interactive effects of boy sufficiency and socioeconomic
status are negative for DCU and positive for LF, unambiguous sign expecta-
tions for four of seven socioeconomic variables in the semireduced form
model cannot be derived. These points comprise the sixth major conclusion
of our reduction exercise.
Discussion
The conclusions we have reached here about the implied and actual
semireduced form coefficients depend on certain assumptions, especially
those involving the effects of sex preference. Expectations about the
signs of many of the semireduced form coefficients depend on the effects
of sex preference, especially in transitional settings. It therefore
appears that these preferences are crucial to understanding the effects
of soazoecenomic variables on CM, LCU, and CEB. m us, if SOB in inter-
action with socioeconomic status is expected to decrease LCU and increase
OF, there Is no point in regressing LCU and LF on the socioeconomic
variables because we could not interpret the effects. On the other hand,
if we think alternative assumptions about sex preference are appropriate,
we can reach conclusions of varying firmness about the socioeconomic
effects. ffl ese conclusions concern functional form, as well as expecta-
tions about the nature of covariabilty between implied and actual
semireduced form socioeconomic effects and the degree of transitionality.
This exercise offers several payoffs. First, we have been able to
show what expectations about socioeconomic effects depend on. Second, we
have shown that given key assumptions, it is possible to derive expecta-
tions for socioeconomic effects that not only are quite specific, but
also differ from usual expectations not explicitly based on a structural
model such as ours. Third, we have pinpointed areas within the model
which deserve highest priority, in particular the boy and girl sufficiency
variables. If the effects of these variables turn out to be minimal or
follow the patterns leading to the expectations delineated in Table 1.3,
Part A, there will be grounds for using the estimation of LCU and CEB
based on insights developed in this section to motivate our empirical
analyses. Finally, we have shown that contextual differences in the
semireduced form model of CM will be concentrated in intercept differ-
ences, rather than in variation in socioeconomic effects.
1.5 CONCLUSION
We have proposed, justif led, and explored a model that organizes and
synthesizes hypotheses about the determinants of fertility and related
behaviors . m is model is designed for use with cross-sectional survey
data sets, especially those collected by the World Fertility Survey.
Although the discussion has focused primarily on the assumptions and
hypotheses embodied in the model, the major operational issues have
received attention as well. In developing the model, we have concentrated
on two main problems: the establishment of a set of micro-level struc-
tural equations and the formulation of hypotheses about structural
Representative terms from entire chapter:
implied semireduced
