published_or_final_version / Geography and Geology / Master / Master of Arts

Includes bibliographical references (leaves 71-74). / This study estimates the mortality of the South African oldest old age population (in five year age groups from age 75 up to the open age interval 100 and above) and in the process re-estimates the numbers of people in the population at these ages at the time of the 1996 and 2001 censuses, and the 2007 Community Survey. In countries where the data on the old age population have been verified, it has been observed that the data are marred by errors in the form of age exaggeration, age digit preference, relative under/over count of the population and under-registration of deaths. These errors have been observed to have the net effect of underestimating mortality of the oldest old age groups. The current research applies the method of extinct generations to estimate indirectly the population numbers at the oldest old age groups (75 up to 100 and above) using data on reported deaths alone. Age heaping and year of birth preference in the reported deaths are assessed using ratios of the probability of death estimated from the data. Age exaggeration in the data on reported deaths is assessed using ratios of deaths compared with same ratios from a standard population. Age heaping and year of birth preference in the census/survey population is assessed using the modified Whipple's Index of age accuracy. The Generalized Growth Balance (GGB) and Synthetic Extinct Generations (SEG+delta) methods are applied to adjust for under reporting of deaths and to assess patterns of age exaggeration in the census/survey population. The difference between the estimates of the completeness of reporting of deaths from the two methods is small (less than 1 per cent) and has been observed to have little impact on the mortality estimates. Final estimates of the completeness of reporting of deaths used are those derived using the SEG+delta method. After re-estimating the population numbers and adjusting for completeness of reporting of deaths, mortality rates were then estimated. Results obtained from the method of extinct generations suggest that there is no systematic difference between the census/ survey population and the population numbers estimated from deaths except at ages 95 and above. Measures of age accuracy show that there are patterns of preferring 1910, 1914, 1918, 1920 and 1930 as the years of birth in the census/survey population and these patterns are also found in the registered deaths. The impact of these errors was investigated and the results show that preference of certain years of birth cause fluctuations in the mortality rates. Patterns observed after applying the SEG+delta method suggest that the completeness of reporting of deaths falls with age at the advanced ages (from age 90 and above) and as a result, the estimated mortality rates above this age are lower than those estimated from the United Nations Population Division (UNPD) and US Census Bureau (USCB) population projections, and Dorrington, Moultrie and Timaeus (2004). Conclusions reached are that the mortality rates for the age groups 75 to 89 derived after re-estimating the population numbers and after allowing for the fall in the completeness of reporting of deaths are lower but not significantly different from those inferred from the UNPD and USCB population projections, and estimates derived by Dorrington, Moultrie and Timaeus (2004). The research recommends mortality estimates from the UNPD since they are the closest to the estimates derived using the published census population numbers for the whole period between the nights of 9-10 October 1996 and 9-10 October 2001. However, the research produced better estimates of the oldest old age population numbers relative to the census/survey numbers.

Includes bibliographical references. / Environmental health hazards are pathogens and chemicals in the environment, which can cause health problems. The importance of such environmental factors in child health and survival are acknowledged in the literature. However, empirical researches on the effect of environmental health hazards on child health and survival are rare in sub- Saharan Africa. This study assesses the effect of household environmental health hazards on under-five mortality in sub-Saharan Africa. The study has used DHS data sets of the following 12 countries in the region: Burkina Faso, Burundi, Cameroon, Cote d’Ivoire, Ethiopia, Gabon, Guinea, Malawi, Niger, Rwanda, Senegal and Zimbabwe. These countries constitute roughly 26 per cent of the region’s population. The study has employed principal component method to construct an index of the level of household environmental health hazards using the following indicators: water source, type of toilet facility, flooring material, type of wall, type of roof, type of cooking fuel and location of water source. I have used a multilevel discrete-time hazard model to assess the relationship between the environmental index and under-five mortality after controlling for the effects of a number of socioeconomic, biodemographic and community-level characteristics.

International migration is the movement of people across national boundaries, and it is an important mechanism for globalisation and economic development. However, in third world countries, it means a large proportion of the population leaving. It is hard to come by statistics on emigration due to the unavailability of sound administrative data systems that record the number of departures from the country. This research seeks to estimate the net number of Zimbabwean migrants for the period 1992 to 2012, by using census data from Zimbabwe and census data from the major receiving countries of Zimbabwean migrants (South Africa and the UK) and data from the Department of Economic and Social Affairs (United Nations 2017e) for other receiving countries. The research also explores alternative estimates of the net number of Zimbabwean migrants implied by other data sources and how they compare to the estimates derived by this research. This research found that the number of Zimbabweans that left the country during the period 1992 to 2012, is between 761,682 and 1,462,620. Furthermore, the results of this research suggest that Zimbabwe is a net emigration country and the net number of Zimbabwean decreased in the second intercensal period compared to the first intercensal period. In addition, the estimates derived in this research show that migration is concentrated in the economically active age groups. Also, a notable increase in the number of female migrants is observed. A comparison of estimates derived in this study to estimates by other data sources indicated that our estimates for the net number of Zimbabwean migrants for the two intercensal periods are plausible.

Includes bibliographical references (p. 196-206). / Focusing on four shantytowns in the northern Namibian town of Oshakati, this study analyses the coping strategies of the poorest sections of such populations. I ask what it is that enables some people living in oppressed and poor urban shantytowns to strive to go on with their lives or improve their situation, while others living in the same context and under the same conditions seem trapped in chronic poverty and apparently give up making much of their lives? The study is based on fieldwork conducted intermittently from 1991 to 2001, using qualitative anthropological methods supplemented by quantitative measures of material poverty. It combines theories of political, economic and cultural structuration, and of the material and cultural basis for social relations of inclusion and exclusion as practise.

This study examines the trends and socio-demographic determinants of adolescent fertility in Zimbabwe. The study uses all six ZDHS surveys that have been conducted for Zimbabwe between 1988 and 2015. Adolescent fertility trends were examined using age-period and cohort-period fertility estimates. The Poisson regression model and the tfr2 module developed by Schoumaker (2013) are used to calculate age-period fertility estimates (ASFRS). Cohort- period fertility rates (CPFRs) were calculated using a method developed by Moultrie, Dorrington, Hill et al. (2013b). ASFRs and CPFRs trends were constructed for the 15 year prior to each ZDHS survey. The trends in both the ASFRS and CPFRs showed that total fertility and 5-year fertility levels above the age of 20 years has significantly declined from the late 1980’s to the mid to around 2010 and since 2010 the fertility levels in these age groups have remained almost constant. However, fertility levels in the 15-19 years age group have been fluctuating around 110 births per 1000 women with no sign of a declining trend since around 1985. The second part of the analysis investigated the socio-demographic factors that have been influencing adolescent fertility in Zimbabwe. Two multiple logistic regression models based on the McDevitt, Adlakha, Fowler et al. (1996) model of proximate determinants of adolescence fertility were used to examine the association between eight socio-demographic factors and adolescent fertility. Results of logistic regression analysis revealed that a significant association exists between adolescent fertility and use of contraception, age at first sex, age of the respondent, marital status, highest level of education attended and employment status at the time of the survey. The odds of giving birth prior to each survey were higher among adolescents who had ever used contraception, initiated sexual activities at a very young age, older adolescents, were married, with low level of education ever attended and those who were unemployed at the time of the survey. This study concluded that adolescent (15-19 years) fertility rates have remained high despite a decrease in all the other age specific and total fertility rates. There is need to introduce and evaluate existing policies and programs that focus on improving socio-economic conditions of adolescents women in Zimbabwe.

Includes bibliographic references (leaves 74-79). / The summary birth history method has been an integral part of the measurement of childhood mortality in countries with incomplete and inaccurate vital registration systems. Estimates from this method are biased downwards in the presence of HIV/AIDS on account of the violation of the underlying assumptions of the method, mainly the correlation between the mortality of mothers and their children. The longitudinal survey data of the Manicaland HIV/STD Prevention study in Zimbabwe conducted between 1998 and 2005 were analysed to assess the extent of this bias. The aggregate bias was found to be significant, 5-11 percent. However, in practice, it may be counteracted to some extent by other possible biases in the summary birth history method in general, and hence, the impact of HIV on the estimates may not be as significant.

A demographic surveillance system (DSS) is commonly used to generate and handle longitudinal follow-up data relating to demographic and health related events in a specified area. In the Korogwe DSS site, information on vital events such as births, deaths and migration has been collected since the establishment of the site in 2005. The aim was to establish demographic and epidemiological indices so as to assist in the evaluation of health related interventions.

This study uses the 2004 and 2009 Lesotho Demographic and Health Surveys (LDHS) to: 1) identify the risk factors that affect mortality at neonatal, post-neonatal, and child ages, and, specifically, to determine the effect of mother’s HIV status on child mortality; 2) investigate how the risk factors that affect mortality have changed between the two periods, 2000-2004 to 2005-2009; and 3) determine if the risk factors are age dependent, that is, whether the effects of risk factors vary for different child ages.

Includes abstract. / Includes bibliographical references (leaves 71-73). / This study utilises the 1996 and 2001 Censuses, and the 2007 Community Survey to test the orphanhood method mortality estimates against consensus estimates of mortality produced using other methods. In all the two censuses and the survey there were questions on the survival status of the respondent’s biological parents. The orphanhood method is widely used in developing countries where the vital registration is incomplete. In countries where the data on survival of parents has been compared with other mortality estimates, it has been observed that the orphanhood method estimates are biased by adoption effect, selection effect and age exaggeration. In the late 1980s and early 1990s, the advent of HIV/AIDS has also biased estimates obtained from the orphanhood method. Non-independence of the mortality of children and their mothers, relationships between HIV infection and fertility, and changes in age-specific mortality result in biases which affect the accuracy of the method. These biases have been observed to have a net effect of underestimating mortality especially female mortality. An adjusted method has been proposed which reduces error, when working with data taken from populations with a significant HIV prevalence. This adjustment can be applied, but further research to identify revised adjustments would further improve the accuracy of the method. The current research applies four variants of the orphanhood method, the regression variant, UN Manual’s two-survey variant, Timaeus’s synthetic cohort variant and the one allowing for HIV/AIDS proposed by Timaeus and Nunn.