Sources of error and bias in methods of fertility estimation contingent on the P/F ratio in a time of declining fertility and rising mortality

Almost all commonly used indirect fertility estimation methods rely on the P/F ratio. As originally conceived, the ratio compares cumulated cohort fertility with cumulated period fertility on the basis of three, fairly strong, assumptions. The intention of this paper is to interrogate what happens to the results produced by the P/F ratio method as each of these three assumptions is violated, first independently, and then concurrently. These investigations are important given the generally poor quality of census data collected in developing countries, particularly sub-Saharan Africa, and the radically altering demographic conditions associated with a generalised HIV/AIDS epidemic in the region.AIDS/HIV, developing countries, estimation, fertility, indirect techniques

Dispensing with marriage: Marital and partnership trends in rural KwaZulu-Natal, South Africa 2000-2006

This paper describes marriage and partnership patterns and trends in rural KwaZulu-Natal, South Africa from 2000-2006. The study is based on longitudinal, population-based data collected by the Africa Centre demographic surveillance system. We consider whether the high rates of non-marriage among Africans in South Africa reported in the 1980s were reversed following the political transformation underway by the 1990s. Our findings show that marriage has continued to decline with a small increase in cohabitation among unmarried couples, particularly in more urbanised areas. Comparing surveillance and census data, we highlight problems with the use of the ‘living together’ marital status category in a highly mobile population.cohabitation, demographic surveillance system, marriage, partnerships, South Africa, trends

Fertility and Living Arrangements in South Africa

This paper investigates fertility among African women in South Africa. Variation in fertility levels is influenced by such factors as rural or urban residence, and level of education and household income. Differential fertility between women of different language groups is accounted for largely by underlying socio-economic factors. A further factor investigated by this paper is the impact of household structure on fertility in South Africa using the 1993 South Africa Living Standards and Development Study. Household structure is examined from the perspective of women. We focus on whether women live with a husband, or with relatives of their parents' generation, or with relatives of their own generation. The analysis concentrates on women aged twenty or over who are already mothers. For these women, we hypothesise that living arrangements mediate between their socio-economic and cultural characteristics and the number of children that they have borne. Living with relatives from the previous generation is found to have a negligible net impact on the lifetime fertility of mothers. However, women who live with relatives from their own generation have borne about a fifth fewer children than other women of the same age after controlling for the impact of household income, the woman's schooling, regional differentials and urban-rural residence. Women from Nguni language groups have relatively large families. While this largely reflects economic and educational disadvantage, it is also conditional on their living arrangements. Unmarried and separated mothers have about a fifth fewer children than married mothers of the same age. It is within the domestic context that the influence of other characteristics is transmuted into differences in numbers of children. Women's living arrangements have become more diverse over the past thirty years in South Africa. They both modify and mediate the effects of other factors on fertility

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

Distinguishing the impact of postponement, spacing and stopping on birth intervals: evidence from a model with heterogeneous fecundity.

This paper investigates the impact on birth intervals of three distinct birth control strategies: stopping childbearing, spacing births and the postponement of further childbearing for reasons unrelated to women's family-building histories. A macro-simulation model of the family-building process is described that incorporates heterogeneity in fecundability. This model is used to demonstrate that the postponement of further childbearing has a distinctive impact on schedules of duration-specific fertility rates that differs from that of both family-size limitation and birth spacing. In particular, the simulation results, supplemented by an analytical exposition, show that reductions in fertility due to spacing are a function of interval duration and its log, while reductions due to postponement are a function of interval duration and its square. This provides a way to test statistically for the presence of, and distinguish between, differential postponement and spacing in regression analyses of birth history data

Teenage Childbearing and Educational Attainment in South Africa.

The relationship between teenage childbearing and school attainment is investigated using nationally representative longitudinal data drawn from South Africa's National Income Dynamics Study. The analysis focuses on the outcomes by 2010 of a panel of 673 young women who were aged 15-18 and childless in 2008. Controlling for other factors, girls who went on to give birth had twice the odds of dropping out of school by 2010 and nearly five times the odds of failing to matriculate. Few girls from households in the highest-income quintile gave birth. Girls who attended schools in higher-income areas and were behind at school were much more likely to give birth than those who were in the appropriate grade for their age or were in no-fee schools. New mothers were much more likely to have re-enrolled in school by 2010 if they were rural residents, they belonged to relatively well-off households, or their own mother had attended secondary school. These findings suggest that, in South Africa, interventions that address poor school attainment would also reduce teenage childbearing

COVID-19 and all-cause mortality in South Africa – the hidden deaths in the first four waves

Accurate statistics are essential for policy guidance and decisions. However, the reported number of cases and COVID-19 deaths are known to be biased due to under-ascertainment of SARS-CoV-2 and incomplete reporting of deaths. Making use of death data from the National Population Register has made it possible to track in near-real time the number of excess deaths experienced in South Africa. These data reveal considerable provincial differences in the impact of COVID-19, likely associated with differences in population age structure and density, patterns of social mixing, and differences in the prevalence of known comorbidities such as diabetes, hypertension, and obesity. As the waves unfolded, levels of natural immunity together with vaccination began to reduce levels of mortality. Mortality rates during the second (Beta) wave were much higher than mortality in the third (Delta) wave, which were higher than in either the first or the fourth (Omicron) waves. However, the cumulative death toll during the second (Beta) wave was of a similar order of magnitude as that during the third (Delta) wave due to the longer duration of the Delta wave. Near-real time monitoring of all-cause deaths should be refined to provide more granular-level information to enable district-level policy support. In the meanwhile, there is an urgent need to re-engineer the civil registration and vital statistics system to enable more timely access to cause of death information for public health actions.Significance:This study highlights that in South Africa there were about three times the number of excess deaths from natural causes during 2020 and 2021 than reported COVID-19 deaths. Although the cause of death remains unknown, the strong temporal correlation between excess deaths and reported COVID-19 deaths within each province indicates that the majority of excess deaths were associated with COVID-19. Many countries have found it difficult to estimate excess deaths, or to identify and report COVID-19 deaths accurately, demonstrating the value of near-real time monitoring of mortality through the use and demographic analysis of data obtained from the country’s National Population Register