Modelling period fertility: Schooling and intervals following a birth in Eastern Africa

Net benefit of smaller human populations to environmental integrity and individual health and wellbeing

Introduction

The global human population is still growing such that our collective enterprise is driving environmental catastrophe. Despite a decline in average population growth rate, we are still experiencing the highest annual increase of global human population size in the history of our species-averaging an additional 84 million people per year since 1990. No review to date has accumulated the available evidence describing the associations between increasing population and environmental decline, nor solutions for mitigating the problems arising.

Methods

We summarize the available evidence of the relationships between human population size and growth and environmental integrity, human prosperity and wellbeing, and climate change. We used PubMed, Google Scholar, and Web of Science to identify all relevant peer-reviewed and gray-literature sources examining the consequences of human population size and growth on the biosphere. We reviewed papers describing and quantifying the risks associated with population growth, especially relating to climate change.

Results

These risks are global in scale, such as greenhouse-gas emissions, climate disruption, pollution, loss of biodiversity, and spread of disease-all potentially catastrophic for human standards of living, health, and general wellbeing. The trends increasing the risks of global population growth are country development, demographics, maternal education, access to family planning, and child and maternal health.

Conclusion

Support for nations still going through a demographic transition is required to ensure progress occurs within planetary boundaries and promotes equity and human rights. Ensuring the wellbeing for all under this aim itself will lower population growth and further promote environmental sustainability.

Lower infant mortality, higher household size, and more access to contraception reduce fertility in low- and middle-income nations

Although average contraceptive use has increased globally in recent decades, an estimated 222 million (26%) of women of child-bearing age worldwide face an unmet need for family planning-defined as a discrepancy between fertility preferences and contraception practice, or failing to translate desires to avoid pregnancy into preventative behaviours and practices. While many studies have reported relationships between availability/quality of contraception and family planning, infant mortality, and fertility, these relationships have not been evaluated quantitatively across a broad range of low- and middle-income countries. Using publicly available data from 64 low- and middle-income countries, we collated test and control variables in six themes: (i) availability of family planning, (ii) quality of family planning, (iii) female education, (iv) religion, (v) mortality, and (vi) socio-economic conditions. We predicted that higher nation-level availability/quality of family-planning services and female education reduce average fertility, whereas higher infant mortality, greater household size (a proxy for population density), and religious adherence increase it. Given the sample size, we first constructed general linear models to test for relationships between fertility and the variables from each theme, from which we retained those with the highest explanatory power within a final general linear model set to determine the partial correlation of dominant test variables. We also applied boosted regression trees, generalised least-squares models, and generalised linear mixed-effects models to account for non-linearity and spatial autocorrelation. On average among all countries, we found the strongest associations between fertility and infant mortality, household size, and access to any form of contraception. Higher infant mortality and household size increased fertility, whereas greater access to any form of contraception decreased fertility. Female education, home visitations by health workers, quality of family planning, and religious adherence all had weak, if any, explanatory power. Our models suggest that decreasing infant mortality, ensuring sufficient housing to reduce household size, and increasing access to contraception will have the greatest effect on decreasing global fertility. We thus provide new evidence that progressing the United Nation's Sustainable Development Goals for reducing infant mortality can be accelerated by increasing access to family planning.

Pathways to Low Fertility: 50 Years of Limitation, Curtailment, and Postponement of Childbearing

This study applies survival analysis to the birth histories from 317 national surveys to model pathways to low fertility in 83 less-developed countries between 1965 and 2014. It presents period measures of parity progression, the length of birth intervals and total fertility that have been standardized fully for age, parity, and interval duration. It also examines parity-specific trends in the proportion of women who want no more children. Outside sub-Saharan Africa, fertility transition was dominated by parity-specific family size limitation. As the transition progressed, women also began to postpone their next birth for lengthy periods in many countries. During the first half of the fertility transition in much of sub-Saharan Africa and in some other countries, however, women stopped childbearing without targeting particular family sizes. Moreover, birth intervals in sub-Saharan Africa have been lengthening since the onset of the transition. Birth control is not restricted to a dichotomy between limitation and spacing. Other reasons for curtailing childbearing and postponing having another birth also shape countries’ pathways through fertility transition.

Patterns and determinants of short and long birth intervals among women in selected sub-Saharan African countries

Optimal birth spacing (defined as a birth spacing of 24-59 months) is incontrovertibly linked to better health outcomes for both mothers and babies. Using the most recent available Demographic and Health Survey data, we examined the patterns and determinants of short and long birth intervals among women in selected sub-Saharan African (SSA) countries.Reproductive health and sociodemographic data of 98,934 women from 8 SSA countries were analyzed. Unadjusted and adjusted multinomial logistic regression models were used to examine the net relationship between all the independent variables and short and long birth intervals.Overall, the majority of women in all the countries optimally spaced births. However, a significant proportion of women had short birth intervals in Chad (30.2%) and the Democratic Republic of Congo (Congo DRC) (27.1%). Long birth spacing was more common in Eastern and Southern African countries, with Zimbabwe having the highest rate of long term birth interval (27.0%). Women who were aged 35 years and above in Uganda (RRR = 0.72, CI = 0.60-0.87), Tanzania (RRR = 0.62, CI = 0.49-0.77), Zimbabwe (RRR = 0.52, CI = 0.31-0.85), Nigeria (RRR = 0.82, CI = 0.72-0.94) and Togo (RRR = 0.67, CI = 0.46-0.96) had significantly lower odds of having short birth intervals compared to women aged 15-24 years. Older women (above 34 years) had increased odds for long birth intervals in all countries studied (Chad (RRR = 1.44, CI = 1.18-1.76), Congo DRC (RRR = 1.73, CI = 1.33-2.15), Malawi (RRR = 1.54, CI = 1.23-1.94) Zimbabwe (RRR = 1.95, CI = 1.26-3.02), Nigeria (RRR = 1.85 CI = 1.56-2.20), Togo (RRR = 2.12, CI = 1.46-3.07), Uganda (RRR = 1.48, CI = 1.15-1.91), Tanzania RRR = 2.12, CI = 1.53-2.93).The analysis suggested that the determinants of long and birth intervals differ and varies from country to country. The pattern of birth spacing found in this study appears to mirror the contraceptive use and fertility rate in the selected SSA countries. Birth intervals intervention addressing short birth intervals should target younger women in SSA, especially in Chad and Congo DRC, while intervention for long birth spacing should prioritize older, educated and wealthy women.

Positive psychology as a strategy for promoting sustainable population policies

Demographic stability constitutes a paramount global environmental objective. Yet, decades of efforts, highlighting the perils of overpopulation, have failed to slow the rapid global population growth. In considering an alternative strategy, insights from the field of positive psychology are explored for their potential to inform future demographic policies. After briefly reviewing sustainable advocacy efforts, different theories behind individual fertility decisions are presented. Following, key components of prominent successful family planning interventions are analysed using a 'positive psychology' perspective. Three 'positive psychology' strategies are explored for their potential to inform sustainable population: a "direct" approach that emphasizes individual benefits rather than indirect gains through mitigation of damages; an emphasis on the convergence between the collective and individual benefits of two--child families; and application of behavioral change theories in demographic policies to better facilitate sustainable individual fertility decisions. The paper posits that a positive psychology conceptualization offers a promising way to re-think the design of demographic policies and frame sustainable population interventions.

Regional variations in the rural-urban fertility gradient in the global South

The study of regional trends in the rural-urban fertility gradient helps us to understand the pace of completion of the fertility transition and the geography of urban growth in the global South. We question whether the hypothesized inverted U-shaped evolution in rural excess fertility is confirmed in four developing regions, and investigate the underlying fertility dynamics by place of residence. Using multiple surveys for 60 developing countries, we analyze long-term rural and urban trends in cohort fertility. The regional comparison is controlled for the international heterogeneity in the stages attained in the fertility transition and the context of urbanization. We found a clearly inverted U-shaped trend in the rural-urban fertility gradient in Latin America, the Middle East and Northern Africa. In Asia, rural excess fertility remained limited. In sub-Saharan Africa it increased monotonically until the most recent cohorts. These differences stem from variations in the urban-to-rural diffusion of the onset of fertility transition and, in sub-Saharan Africa, from a slower pace of decline in rural areas.

Educational differentials in the realisation of fertility intentions: Is sub-Saharan Africa different?

Background

The gap between fertility outcomes and fertility ideals is notably higher in sub-Saharan Africa (SSA) than elsewhere, relating to both under- and overachievement of fertility ideals. We consider the extent to which the relationship between fertility ideals and fertility outcomes is related to educational achievement. Further, we consider if these educational differentials are the same or different in SSA, and thereby consider the extent to which increasing levels of education in SSA may decrease fertility.

Data and methods

We use 227 Demographic and Health Surveys (DHSs) from 58 countries worldwide to look at population- level measures of the mismatch between fertility ideals and fertility outcomes. Population level measures are used to assess whether the correspondence between fertility intentions and achievements differ by level of education. We then look at the individual-level determinants of both under- and overachieving fertility intentions. Data from the most recent DHS in 54 of the original countries is used for the individual level analysis, with five countries excluded due to the most recent available survey being out of date.

Results

An average of 40% of women in SSA underachieve their stated fertility intentions compared to 26% in non-SSA countries. Furthermore, compared to other LMICs, higher levels of education are not related to better correspondence between fertility intentions and outcomes in SSA. In Middle/Western Africa countries, on average, 48% of women with secondary or higher education have fewer children than their ideal, compared to just 24% who have more children than their ideal.

Conclusion

We argue that the phenomenon of underachieving fertility ideals (or unrealized fertility) may be of particular importance for the ongoing fertility transition throughout SSA, especially as more highly educated groups do not appear to be following the patterns observed elsewhere.