Fertility Desires and the Course of Fertility Decline in sub‐Saharan Africa

This research examines the demand for children in sub-Saharan Africa and how this demand bears on prospects for fertility decline. Fertility levels on average are high in the region. At issue is whether, and how, fertility decline will occur in the near or medium term. In sub-Saharan Africa fertility desires too are generally high, as we have documented elsewhere (Bongaarts and Casterline 2013; Casterline and Agyei-Mensah 2014). The backdrop for this research, then, is high fertility evidently sustained by high demand for children. We confine our analysis to the quantity of children, setting aside desires to space births. Caldwell et al. (Caldwell, Orubuloye, and Caldwell 1992; Caldwell and Caldwell 2002) stress the prominence of birth spacing in sub-Saharan African reproductive regimes, inferring from this that increased birth spacing will play a larger role in African fertility declines than has been the case in other regions. More recently, on the basis of analysis of Demographic and Health Survey (DHS) data Moultrie, Sayi, and Timæus (2012) conclude that “birth postponement” has made a large contribution to African fertility declines to date. Consistent with this argument, Casterline and Odden (2016) document that inter-birth intervals have lengthened during the early stages of fertility decline in Africa. By no means do we seek to dismiss the importance of birth spacing in African reproductive regimes. Rather, to set some reasonable bounds on the present research, our attention is limited to the desired quantity of children, as revealed by survey data on the ideal number of children and the parity-specific preference to have no more children. While it may be the case that intentional birth spacing reduces fertility to a greater extent in Africa societies than in other regions, it is highly unlikely that fertility in African societies will fall below four births per woman, not to mention falling to replacement level, unless most women have just a few children. And this in turn seems very unlikely in the absence of widespread deliberate effort to limit the number of children. That is, the postponement behavior posited by Timæus and Moultrie (2008) by itself seems an inadequate mechanism for reducing fertility to less than four births per woman, given that sexual activity begins at relatively young ages on average. Moultrie, Sayi, and Timæus (2012), while arguing that postponement can exercise a powerful fertility-reducing impact, concede that attainment of low fertility requires adoption of deliberate and effective family-limitation practices. For this reason it is crucial to assess the existing demand for children, and from this assessment to draw some inferences about the prospects for widespread desire to limit family size, which presumably could result sooner or later in lower fertility rates. The social science and demographic literature on family-limitation desires and behaviors in sub-Saharan Africa is not as rich or well developed as the corresponding literature on birth spacing. Instead, over the years many scholars, drawing on a wide range of quantitative and qualitative materials, have concluded that African women's planning horizons for fertility are short and that explicit quantity-of-children targets are for the most part not formulated. This assertion is found not only in scholarship on African reproduction in the past (van de Walle 1992) but also in recent scholarship based on fieldwork in multiple sub-regions as well as analysis of DHS (Agadjanian 2005; Bledsoe 2002; Johnson-Hanks 2005, 2007). Our analysis does not directly challenge this fundamental assertion, because the survey data we analyze do not provide sufficient basis for a rigorous challenge. We do, however, present evidence which is inconsistent with this assertion, evidence which suggests the emergence of a family-limitation mentality in African societies. Our research takes as a given that fertility desires affect fertility; were this relationship weak or non-existent, the rationale for this research would be weakened. More specifically, we assume that declines in desired fertility sooner or later translate into a decline in fertility. We do not interrogate this crucial assumption, but there is abundant empirical research validating it—investigations of the association between fertility desires and fertility outcomes at both the aggregate level (e.g. Lee 1980; Westoff 1990; Morgan and Rackin 2010) and the individual level (e.g. Westoff and Ryder 1977; Schoen et al. 1999). An important conclusion from this large literature is that the association is variable; that is, the correspondence between fertility desires and reproductive behavior is far closer in some settings than in others. No doubt in part this reflects variation across settings in the meaning of responses to the attitudinal items that have been standard in demographic surveys during the past four decades (e.g. Demographic and Health Surveys). More fundamentally, fluctuating correspondence between fertility desires and fertility outcomes is due to variation in the extent to which desires are implemented in those behaviors that directly determine fertility: sexual activity, contraception, and induced abortion (Bongaarts 1978). That fertility desires are imperfectly implemented is explicitly recognized in the notion of “unmet need for contraception”—that is, lack of contraceptive practice among women who state a desire to avoid pregnancy (in the short term or indefinitely) (Casterline and Sinding 2000; Bradley and Casterline 2014). Implementation of preferences is a central concept in the second portion of the analysis presented here, although we do not analyze contraception per se (instead examining rates of unwanted fertility). All this argues for caution in drawing simple inferences about likely future trajectories of fertility in sub-Saharan Africa on the basis of fertility desires alone. The complications just noted, and others (including the dangers of inferring fertility desires from reproductive behavior), are cogently spelled out in Johnson-Hanks (2007). In short, this research has two main goals: (i) to examine fertility desires (number of children) in sub-Saharan Africa: levels as compared to other major regions, and recent trends; and (ii) to assess the extent to which fertility decline in sub-Saharan Africa is contingent on decline in fertility desires (singly, and in combination with other reproductive changes). The empirical analysis relies on information collected in national demographic surveys from 1975 to the present. These surveys were part of four international survey programs: World Fertility Surveys (WFS), Demographic and Health Surveys (DHS), Reproductive Health Surveys (RHS), and Pan-Arab Project for Family Health (PAPFAM).1 Recent data for sub-Saharan Africa are drawn entirely from DHS surveys, while African WFS surveys provide historical depth for some of the analysis. The non-DHS surveys greatly enlarge the coverage of other regions (especially in the pre-decline and early-decline stages), affording sounder comparison with sub-Saharan Africa. In the comparative analysis of historical trends, the sample is 84 countries and 303 surveys, of which 38 countries and 134 surveys are in sub-Saharan Africa.2 In the analysis of prospects for future fertility decline, the sample is limited to 32 sub-Saharan African countries with a survey conducted since 2000. Throughout, the analysis is attentive to differences between sub-regions and countries. In particular, we break Africa into three sub-regions: East Africa (12 countries), Southern Africa (5 countries), and Middle and West Africa (21 countries). This regional breakdown proves a meaningful distinction, as could be anticipated from Cleland, Ndugwa, and Zulu (2011). The remainder of the globe is classified into Latin America and Caribbean (19 countries), South and Southeast Asia (15 countries), and West Asia and North Africa (12 countries). This yields six regional/sub-regional groupings in total. For convenience we refer to these as regions, although strictly speaking the three sub-Saharan African categories are sub-regions. All calculations required for this analysis have been performed by the authors using the individual-level survey data files for the 303 surveys. These demographic surveys offer three measures of fertility desires: ideal number of children; preference for another child: whether another child is desired and, if so, the desired waiting time; and wantedness of recent births, as reported retrospectively. These measures permit construction of multiple indicators of fertility desires. We rely on two of the three items, namely the ideal number of children and the preference for another child. We depend more heavily on the latter because numerous methodological studies have demonstrated that the preference for another child is the most valid and reliable of the three measures listed above (Casterline and El-Zeini 2007). While the prospective preference item is not a direct question about the desired quantity of children, when the responses are tabulated on a parity-specific basis they are revealing of the desired number. For example, if a woman of parity three states that she does not want any further children, one may infer that three (or less) is her desired number. A qualification of this point is that parity and age are confounded: women of higher parity are older ceteris paribus, and to the extent that age independently affects the desire to terminate childbearing, parity-specific desires to stop may reflect considerations of age as well as desired number of children. The prospective preference item, in combination with the birth histories collected in all DHS surveys, provides a basis for calculating wanted and unwanted period fertility rates (TFR). The second portion of the analysis makes use of such rates. The ideal number of children has proven a less reliable, and arguably less valid, indicator of fertility desires than prospective preferences (Casterline and El-Zeini 2007). Test–retest reliability is low. Validity is compromised by an aversion to offering an ideal that is less than the already attained number of children (so-called rationalization) and by non-numeric responses (“up to God”). But the stated ideal number of children has the virtue of being a concise expression of the overall demand for children. We use it here to obtain a first look at fertility desires. To minimize the validity threat presented by rationalization, we limit the sample for analysis of the ideal number of children to women whose first union commenced within ten years of the survey interview. These are mainly younger women with a small or modest number of children ever born, and hence there is less risk of rationalization.3 Women supplying non-numeric responses are excluded. While non-numeric responses have become relatively rare in recent demographic surveys in sub-Saharan Africa and elsewhere (Frye and Bachan forthcoming), in a minority of the surveys in our research such a response is relatively prevalent: in about 20 percent of the surveys the proportion of women providing a non-numeric response exceeds 10 percent (among women within ten years of start of first union). As noted, this is one reason for favoring prospective preferences as an indicator of fertility desires. There is some variation among the survey programs in the questionnaire item that asks for the respondent's ideal number of children: WFS has the deviant wording. The additional clause in the DHS has been demonstrated to reduce slightly the reported ideal number of children, presumably by reducing the extent of rationalization. Hence the WFS item yields a higher ideal ceteris paribus, producing a slight exaggeration of the decline in the ideal in those countries where the first survey is WFS. As is the case with the ideal number of children, the fertility preference items in these survey programs are similar but not identical: Again the outlier is the WFS, which offers only the affirmative side and therefore is subject to acquiescence bias. To the extent such bias occurs, it will cause upward bias in WFS estimates of the desire for another child, leading to an exaggeration of the decline in the proportion of women wanting another child (because in countries with a WFS it is historically the first survey). Note that trends in the ideal number of children and prospective preferences are subject to bias in the same direction when the WFS is the earliest survey. Because the prospective preference item was administered only to currently-in-union women in some surveys (as against both never-in-union and currently-in-union women in other surveys), we confine the analysis of prospective preferences to currently-in-union women, to ensure that estimates of variation across countries and over time are not affected by differences in sample selection on union status. For the descriptive analysis of levels and trends—the first step in this research—estimates are generated survey-by-survey. These estimates are then pooled within region, and the remainder of the analysis relies on these survey-level estimates. With these survey-level estimates, trends are calculated country-by-country, and for summary purposes a regression line is estimated region-by-region with fixed effects for country. This fitted regression line can be viewed as a convenient average of the within-country trends. The regression specification has linear splines—connected straight lines with disjuncture at “knots” —to accommodate trends that are non-linear (i.e. more rapid or slower pace of change at different stages of fertility decline). The second step in this research is to assess the role of fertility demand as an obstacle to fertility decline in sub-Saharan Africa and, conversely, to consider how declines in desired fertility might facilitate decline. We conduct this assessment through a simulation exercise that employs a reproductive model containing fertility desires as an explicit element, thereby allowing for an examination of the responsiveness of fertility to hypothetical changes in desires. We adopt this approach to generate a balanced and numerical assessment of the potential effect on fertility rates in Africa of changes in fertility desires. The reproductive model is as follows: If the product rnpn is regarded as the nuptiality component—the proportion never married and the fertility rate among the never married4—equation 1 can be viewed as an expression for fertility with four essential elements: This equation establishes terms for the debate about the relative weight in determining fertility decline of fertility demand vs. implementation of this demand that differ from those that have been common in the scholarly literature to date, most notably as articulated in the highly influential article by Pritchett (1994). We develop this point in the final section. A distinctive feature of equation 1 is the two elements rw and ru. We term these conditional rates (wanted and unwanted, respectively), because the denominators for these two rates are restricted to woman-years during the reference period wanting or not wanting another child, respectively (among ever-in-union women). That is, these are rates conditional on fertility preferences. By contrast, conventional unconditional wanted and unwanted rates (e.g. as routinely calculated from DHS surveys) include all women in the denominator. The denominators for the conditional rates are obtained by assuming that parity-specific desires for another child at the time of the survey apply to the entire reference period. Because the conditional rates are restricted to ever-in-union women at risk of wanted or unwanted births, they are more appropriate than unconditional rates for examining the implementation of fertility preferences. They also provide more direct counterparts to demand satisfied, an increasingly popular refinement of unmet need for contraception (Bradley et al. 2012). Demand satisfied is contraceptive prevalence among women who want to postpone or stop childbearing; that is, its denominator is restricted to women who want to avoid pregnancy. Unmet need, by contrast, includes all women in the denominator (although typically only currently-in-union women) and therefore is an unconditional measure. nuptiality: more adult years spent never-in-union preference composition: more ever-in-union years spent not wanting another child (vs. wanting a child) wanted rates: decline in rate of childbearing among those wanting another child (conditional wanted rate) unwanted rates: decline in rate of childbearing among those not wanting another child (conditional unwanted rate) The second source reflects changes in the desired number of children. The third and fourth sources are matters of more effective birth control, which can be achieved via either contraception or induced abortion. (A decline in sexual activity would also depress these rates.) That is, the third and fourth sources connect this research to the central concepts “unmet need for contraception” and “satisfaction of demand.” On the basis of equation 1, one can perform simulations that generate hypothetical fertility change (change in TFR) when one or more of the elements of the equation are assigned different empirical values. Numerous simulations might be informative; the crucial decision is the choice of alternative values. We ask: based on this equation, how would present levels of fertility in sub-Saharan Africa change if there were an instantaneous shift to values of each element as observed in contemporary low-fertility populations in other regions? For the latter, we use data from seven national surveys that yield a TFR below 2.3 births per woman.5 Substitution of this set of alternative values element-by-element6 yields hypothetical age-specific fertility rates that are then summed to hypothetical TFRs.7 For this simulation exercise, the starting point is the most recent survey since 2000 in 32 sub-Saharan African countries in East, Middle, and West Africa, along with the average values from the seven low-fertility surveys (see endnote 5).8 We use a 36-month reference period for the fertility rates (months 1–36 preceding the survey). Wanted vs. unwanted fertility is calculated via the “aggregate prospective” method of Casterline and El-Zeini (2007). This method relies on the prospective fertility preference item, which as reported above is generally recognized as the most valid and reliable of the core fertility desires items used by the major survey programs. Typically the aggregate prospective method produces higher estimates of unwanted fertility than other available methods.9 We present the results in two sub-sections, corresponding to the two main steps in this research. This discussion lays out the empirical facts; we postpone most of our to the final section. To obtain an of levels of fertility desires and association with levels of with an on we consider the ideal number of children reported by women who are within ten years of the start of first The level of fertility is by the period fertility rate for 1–36 preceding the survey. The data for this analysis are in and trends for 84 as from 303 surveys, for each of the six regions. The trends are with and the fitted line for the is a Note that the is ideal number of children that to fertility decline. As fertility declines as ideal fertility there is no evidence of from this But the rate of decline across regions, and, of more conditional on ideal number of children the level of fertility across regions. conditional on level of the ideal number across regions. These are more in and in one the six regional fitted is most in this is the higher ideal number of children in the three sub-Saharan sub-regions as compared to the three other major regions. The ideal is high in Middle and West Africa. For more fitted at a selection of ideal number of children the data permit is, when the ideal between and TFR exceeds the ideal by a in sub-Saharan Africa than in Latin America and the Caribbean and in South and Southeast That is, there is closer correspondence between ideal and fertility in from a comparative the closer correspondence between ideal and fertility is a distinctive feature of the reproductive in sub-Saharan at the aggregate level ideal and fertility are more in in Africa than in other regions. This suggests less fertility in sub-Saharan Africa, a conclusion in more direct of unwanted fertility rates and 2014). of unwanted births is to with less to deliberate birth control, when the ideal number of children is A further from and documented in the closer correspondence between the rates of decline in ideal and fertility in the three sub-Saharan African regions as compared to the other three major regions. In these latter three regions, the are well in of more than a decline in TFR for each decline in the ideal number of children. That is, fertility more than ideal fertility. This is not in of the higher fertility in the regions at the of fertility in these regions, as compared to Africa, there was more for fertility decline to of of fertility. But this of in does not by the ideal number of children in the regions, fertility declines could have in the of is, near By the same the less than in East Africa and Middle and West Africa when the ideal is greater than that fertility in the early stages of fertility decline in these African regions. We drawing on past methodological research, that the ideal number of children is an as compared to the prospective preference for another child, and the latter a more of the of fertility desires as the reproductive In and we examine historical trends in the parity-specific desire to stop childbearing in African countries in East Africa and in Middle and West The countries are on the basis of and the of a of surveys. The of women a preference not to have another child is for women of parity and These for of both levels and historical trends. This is the only portion of our analysis that explicitly by historical consider in and reflects an with parity in the desire to An with parity is with a is, a desire to terminate childbearing a number of births have No with in contrast, would an absence of the family-limitation as is in research by Johnson-Hanks and Moultrie, Sayi, and Timæus In the the survey data that women are to a desire to childbearing and, that this desire with in the period since 2000. In East Africa the between women of parity and women of parity is on the of in the recent period. The is of in Middle and West Africa but on the of in most countries. This is the case in the with the of In short, Africa the desire to stop childbearing with a revealing of a about the reproductive that is with family-limitation these data we whether women have time horizons whether they to a relatively fixed number of children. But on these estimates the notion that birth is an concept in recent decades in the societies of sub-Saharan Africa. consider trends. The in and is In most countries there is at parity this that desires have not At higher parity there is an upward in most countries. In an upward at parity and is less in the countries of Middle and West the of countries there at parity parity of the countries. family in a at is itself more in East and Southern Africa than in Middle and West Africa. The assessment of trends in and is by of the association between the desire to stop childbearing and the fertility rate in and and and These and the same as the analysis of the ideal number of children in and and and The and are to parity which the important between women to stop at a small number of children and those who to to a or large number. is from and that the TFR declines as the desire to stop at parity The trends the fitted regional and some is East Africa and Latin America and but on the the of association is The fitted regional are and presented in and assessment suggests that the are in the three African regions. A means a larger decline in TFR for each point in the desire to The of the fitted lines presented in only this A more valid is that the can be regarded as among and both this The regional differences in and not conditional on fertility preferences (i.e. to stop childbearing at parity the TFR to be lower in sub-Saharan Africa than in the other regions. at high levels of fertility (e.g. the parity-specific desire to stop to be lower in sub-Saharan Africa and in Middle and West Africa. to this in the low TFR in South and Southeast Asia when the desire to stop is low (i.e. of fertility decline). the overall is for the TFR to be lower in Africa when one on the parity-specific desire to stop We this regional mainly reflects that average inter-birth intervals in many African societies (Casterline and Odden is, lower rates of childbearing among women who want more children in sub-Saharan Africa as compared to other regions. A look at also yields differences between the African regions that lower fertility conditional on preferences in Middle and West Africa as compared to East Africa lower desire to stop in Middle and West Africa than in East Africa at any given level of fertility). This is with all the results to this results from our analysis of the ideal number of children: a stated desire to limit family is far less in Middle and West Africa. the conclusion from and that the desire to stop at a number of children has increased during the past years in some African countries. from the fitted lines in if recent trends were to within a or the of women in East Africa will counterparts in Latin and North Africa in to limit childbearing to a small number of children than This is already the case in Southern Africa. The same be of Middle and West Africa, which has far more to to the with regions in the desire to