Volume 37 - Article 40 | Pages 1327–1338  

On the pace of fertility decline in sub-Saharan Africa

By David Shapiro, Andrew Hinde

Response Letters

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24 January 2018 | Response Letter

Response to “Comparisons to Limited Regions and Without Controls Make Africa Look Slower Than It Is”

by David Shapiro

We thank Lyman Stone for his comments on our paper and offer the following thoughts in reply.

Our paper (Shapiro and Hinde 2017) is descriptive and focused purely on comparing the pace of the fertility declines that emerged in the second half of the twentieth century in major regions of the developing world. The paper shows that, when looking at aggregate fertility in each of four regions, fertility decline from peak fertility in sub-Saharan Africa (SSA) has been distinctly slower than in the other three regions that we examine. Indeed, the last graph in Stone’s ‘Another look at long-run fertility and how it compares globally’ (Stone 2017) shows that compared to Latin America and the Middle East and North Africa, decline in SSA has been distinctly slower.

Stone argues that it is desirable to broaden the scope of analysis, and to this end, he presents data for the United States (US), beginning with the onset of the nineteenth century. That data shows slower decline early on in the US than in recent and contemporary SSA. Adding this historical perspective is an interesting contribution, but if we were to follow that route we should also want to include historical Europe, which would reveal additional, quite complex, trajectories. However, this goes well beyond our more limited focus.

The other part of Stone’s discussion emphasizes that our failure to control for various factors that are likely to influence the pace of fertility decline makes fertility decline in SSA look slower than it is. This contention is somewhat puzzling. Our paper simply takes the fertility declines in the four regions we studied at face value. And, taken at face value, the fertility decline in SSA is substantially slower than that in the other three regions. This is an important point in its own right, as it has profound implications for the future of the world’s population, and for the future development prospects of SSA. 

There is a good deal of literature indicating that socioeconomic development, including urbanization, women’s education, and infant and child mortality, is important as an influence on the pace of fertility decline (on women’s education, see Shapiro 2012). And this literature suggests that a slower pace of development characterizes much of SSA and thereby contributes to its slower pace of fertility decline among developing-country regions (Bongaarts 2008). It would be great to do a piece of research to examine this suggestion, but it would be a much more ambitious undertaking than the simpler exercise we did in our paper. There is also evidence that fertility decline in SSA has been robust in urban places and comparatively weak in rural areas (Shapiro and Tenikue 2017). This suggests a possible explanation for slower fertility decline in the early nineteenth century US compared to late twentieth century SSA: lower rates of urbanization in the US.

We could also hypothesise that there is something different about fertility behavior in SSA compared with the other regions (for example the relationship between contraceptive prevalence and fertility), such that the relationship between development and fertility is different there. However, a recent paper by John Bongaarts has cast doubt on this (Bongaarts 2017).

To summarise, our focus is on the gross differences among regions in the pace of fertility decline. Gross values are important, especially for fertility, as it is gross values that determine the number of babies born, which in turn affects population growth. When Stone argues that we should control for relevant factors, he is essentially suggesting that we should instead look at net differences. But that is a more extended piece of analytical research, and goes well beyond our descriptive focus.   

David Shapiro and Andrew Hinde


Bongaarts, J. (2008). Fertility transition in developing countries: progress or stagnation? Studies in Family Planning 39: 105‒110.

Bongaarts, J. (2017). The effect of contraception on fertility: is sub-Saharan Africa different? Demographic Research 37(6): 129‒146.

Shapiro, D. (2012). Women’s education and fertility transition in sub-Saharan Africa. Vienna Yearbook of Population Research 10, Education and the Fertility Transition (Vienna, Austrian Academy of Sciences Press): 9‒30.

Shapiro, D. and Hinde, A. (2017). On the pace of fertility decline in sub-Saharan Africa. Demographic Research 37(40): 1327‒1338. 

Shapiro, D. and Tenikue, M. (2017). Women’s education, infant and child mortality, and fertility decline in urban and rural sub-Saharan Africa. Demographic Research 37(21): 669‒708.

Stone, L. (2017). Another look at long-run fertility and how it compares globally, https://medium.com/migration-issues/another-look-at-long-run-fertility-f6e63358e242 [accessed 19 January 2018].

03 January 2018 | Response Letter

Comparisons to limited regions and without controls make Africa look slower than it is

by Lyman Stone

The decline in African fertility can be considered in several ways. First, it can be considered in a raw, absolute sense, as this article does. But if it is simply to be considered without any controls, such as for rurality or income, if we want to know unconditional fertility, then restricting the window of comparison to North Africa, Asia, or Latin America is incomplete. We should also consider the fertility transitions in other parts of the world, such as the United States during the 19th century. Long-term estimates of fertility decline in the United States show African fertility falling faster than American fertility did. You can find a detailed discussion here: https://medium.com/migration-issues/another-look-at-long-run-fertility-f6e63358e242

The objection may be raised that comparisons to the 19th century are invalid because of technology changes, most notably re: contraception. But this concern itself would suggest that this Descriptive Finding may not correctly compare regions, since contraceptive access and use in Africa is fairly low, and US TFR fell below 3 well before widespread usage of modern contraceptives, that is, Africa's high-fertility countries today may indeed be quite analogous to 19th century fertility conditions in parts of the United States. Any objection to comparison with the 19th century American experience can easily be raised as well to suggest that comparison with other regions vs. SSA may be invalid for similar reasons.

To interpret these Descriptive Findings, then, one must keep in mind the differences in conditions between Sub-Saharan Africa and the regions Shapiro compares to.  One wonders whether urban TFRs and rural TFRs in Africa might show a more similar convergence path, though of course this would be confounded by challenges in similarly defining rurality across regions; the point, however, is that since rurality relates to fertility, an apples-to-apples comparison of regions requires a control for rurality to fully understand the finding.

Alternatively, rather than looking at transition over time, another measure of transition might be income. It may be presumed that the authors do not assert that the numbering on a year has a causal impact reducing fertility; the implication in the use of a time variable is that time proxies for something else, some underlying process, which we might call "development." But the degree to which time proxies for development may, indeed probably does, vary across contexts. It would therefore be prudent to model development directly; assess fertility vs. consumption per capita, or an income estimate, or HDI, etc. This might still show a sluggish African transition, or it might not. Authors understandably did not conduct this work in a short descriptive finding, but it is difficult to know the proper interpretation of this finding without considering fertility measures under different conditions, such as income levels, educational attainment, or rurality. If African fertility turns out to be very close to where we would expect given its level of income or development, then one would think that sluggish transition narratives would be worth reformulating: if delayed fertility is simply due to delayed urbanization, less education, or lower incomes, then fertility-targeting policies may have modest effects, and indeed it may be more proper to speak of African fertility transition as conditionally equivalent to other regions of similar traits. Determining such would require additional work not envisioned in this paper, but would seem important to determining the conditional validity of the thesis offered. And indeed even on an unconditional basis the comparison to US transition suggests African fertility transition may not be as relatively slow as presented.

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