Journal Articles

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Open Access
Development of a boundary setting algorithm based on migration rates estimated using BayesAss and its preliminary application to TOSSM datasets
(2007) Edwards, Charles T T; Butterworth, Doug S
A Boundary Setting Algorithm (BSA) is developed that utilises migration rates estimated by the program BayesAss. It is subjected to preliminary testing through application of the BSA to a subset of TOSSM datasets from Archetypes I and II. Two Fully Internally Mixed Areas (FIMAs) are considered, connected by varying rates of migration. The objective of the BSA, implemented through the run.tossm control program, is to decide whether to manage FIMAs as one or two units. Performance is assessed using the depletion and catch statistics produced by run.tossm. Although BayesAss has the potential to provide information relevant to management, performance of the BSA was found to be poor, apparently due to inconsistent and unreliable estimation of the migration rate.
Open Access
Embedding open data practice: Developing indicators on the institutionalisation of open data practice in two African governments
(2015-06) van Schalkwyk, Francois; Willmers, Michelle; Schonwetter, Tobias
Final research report of the “Embedding open data practice: Developing indicators on the institutionalisation of open data practice in two African governments” project, which formed part of the World Wide Web Foundation’s "Emerging Impacts of Open Data in Developing Countries" Phase 2 initiative. In order to address the principle question of whether open data practice is being embedded, the project undertook a comparison of government open data in South Africa and Kenya, with a particular focus on open licensing as a key indicator of openness.
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Finalised Assessment of the South African anchovy resource using data from 1984 – 2011: results at the posterior mode
(2012) De Moor, Carryn L; Butterworth, Doug S
The operating model (OM) for the South African anchovy resource has been updated from that used to develop OMP-08 given five more years of data, a revised time series of commercial catch and November survey proportion-at-age 1 estimates provided by a new approach. A Beverton Holt stock recruitment relationship is used, marginally supported by the AICc model selection criterion over a Ricker stock recruitment relationship. Time-invariant natural mortality is assumed at 1.2year-1 for both juvenile and adult natural mortality; an increase from that assumed for the OM from which OMP-08 was developed, with the change made because of a better fit to the data and avoidance of the questionable implication that the recruit survey detects a greater proportion of the recruits than the November survey detects of the adult biomass. There has been a decrease in recruitment residual standard deviation and in recruitment autocorrelation for this updated OM compared to the values used in previous OMs. The impact of this on the appropriate choices of a risk definition and threshold for the new OMP to be developed needs to be considered. The resource abundance has dropped below the historic (1984-2010) average, with a model-estimated spawner biomass of 1.2 million tons in November 2011, following 2 years of below average recruitment. Only four out of the past 13 years have produced below average recruitment. The harvest proportion over the past 11 years has not exceeded 0.13.
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A Generalized Linear Model applied to the South Cost rock lobster CPUE data to obtain area-specific indices of abundance
(2008) Glazer, Jean Patricia; Butterworth, Doug S
Area-disaggregated assessments for South Coast rock lobster are currently being developed. An important input to these assessments is the catch per unit effort (CPUE) data. A Generalized Linear Model (GLM) has been applied to the data to obtain areaspecific standardized indices of abundance for input to the assessment models.
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GLM and GLMM standardisation of the commercial abalone CPUE for Zones A-D
(2012) Brandão, Anabela; Butterworth, Doug S
This paper presents an update of the standardisation of the abalone CPUE using the conventional GLM approach and adding new data for the 2010/2011 fishing in Zones A and B. A GLMM approach to standardising abalone CPUE data is also investigated.
Open Access
The impact of highly active antiretroviral treatment (HAART) on employment in Khayelitsha
(2007) Coetzee, Celeste
This paper examines the impact of Highly Active Antiretroviral Treatment (HAART) on labour force participation of people living with HIV/AIDS in Khayelitsha, South Africa. Cox Proportional Hazard Models with stratum effects for three medical clinics, and Accelerated Failure Time Models with individual specific unobserved shared effects (frailty), are estimated for transitions from inactivity to unemployment, and transitions from unemployment into employment, using a longitudinal data set. The findings of this study indicate that HAART leads to greater activity in the labour market, but there was not a strong effect on re-entry into employment.
Open Access
Impact of the sectoral determination for farm workers on the South African sugar industry: case study of the Kwazulu-Natal North and South Coasts
(2007) Murray, Justin; Van Walbeek, Corné
A survey of 103 sugarcane farmers on the KwaZulu-Natal coast was conducted in order to analyse the impact of the Sectoral Determination for Farm Workers (2002) on South African agriculture. The sample was separated into a high wage paying North Coast and lower wage paying South Coast. Typically farmers were unable to distinguish between the impact of the Sectoral Determination and other labour laws. Results indicate that the impact of the legislation is similar in each region. No respondents reported mass retrenchment, but job shedding is disguised by not replacing workers (especially unskilled workers) that leave the farm. A sizeable number of growers (17 per cent on the South Coast and 44 per cent on the North Coast) have reduced the working week to 27 hours (or 36 hours in the Felixton Mill Group Area) enabling them to pay wages on an hourly, rather than a weekly basis. This strategy reduces the effective wage. About 40 per cent of growers have reduced the in-kind benefits to their workers. About half of respondents indicated that they are likely to increase their use of seasonal and contract labour in future. Although a majority of respondents indicated that they considered mechanisation of the harvesting process, cost and topographical factors currently does not make this a serious alternative to manual harvesting. However, because of increased wage costs and the relatively strong currency in recent years, chemical weed control has become an attractive alternative to manual weed control.
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Initial investigation of generic management procedures for data-poor fisheries
(2010) Geromont, Helena F; Butterworth, Doug S
The vast majority of fish stocks in South Africa are not managed quantitatively as there is not sufficient data (such as an index of abundance) on which to base a resource assessment. In addition, these stocks are relatively “low-value”, which renders dedicated scientific management too costly, and a generic approach is therefore required. The aim of this work is to design and test some very simple “off-the-shelf” management procedures (MPs) that can be applied to groups of data-poor fisheries that share some key characteristics in terms of demographic parameters. For this initial investigation, a selection of empirical MPs is simulation tested on a wide range of operating models (OMs) representing the underlying dynamics of the resource in order to ascertain how well the different MPs perform. While the data-rich MPs perform somewhat better than the data-poor ones, as would be expected, it seems that the very simple data-poor MPs are surprisingly robust to a wide range of uncertainty for key parameters and could well be candidates to manage the South African data-poor stocks, ensuring perhaps not optimum, but at least relatively stable sustainable future catches.
Open Access
The material and political bases of lived poverty in Africa: Insights from the Afrobarometer
(2008) Mattes, Robert
The Afrobarometer has developed an experiential measure of lived poverty (how frequently people go without basic necessities during the course of a year) that measures a portion of the central core of the concept of poverty not captured by existing objective or subjective measures. Empirically, the measure has strong individual level construct validity and reliability within any cross national round of surveys. Yet it also displays inconsistent levels of external validity as a measure of aggregate level poverty when compared to other objective, material measures of poverty or well being. Surprisingly, however, we find that lived poverty is very strongly related to country level measures of political freedom. This finding simultaneously supports Sen's (1999) arguments about development as freedom, corroborates Halperin et al’s (2005) arguments about the “democracy advantage” in development, and increases our confidence that we are indeed measuring the experiential core of poverty.
Open Access
“Not a single white person should be allowed to go under”: Swartgevaar and the origins of South Africa’s welfare state, 1924-1929
(2006) Seekings, Jeremy
South Africa developed, during the course of the twentieth century, an exceptional welfare system based on social assistance rather than social insurance, and focused especially on old-age pensions. The origins of South Africa’s welfare state lay in the 1920s, not in the 1930s as has generally been suggested. This paper examines the process leading to the 1928 Old Age Pensions Act, paying particular attention to the 1926-28 Pienaar Commission on Old Age Pensions and National Insurance. The introduction of old age pensions enjoyed the support of all parties representing white and coloured voters in Parliament, but for diverse reasons. For the National Party and Labour Party – partners in the coalition Pact Government of 1924-29 – non-contributory old-age pensions were a crucial pillar in the ‘civilised labour’ policies designed to lift ‘poor whites’ out of poverty and re-establish a clear racial hierarchy. Welfare reform was thus, in significant part, a response to the ‘swartgevaar’ or menace of black physical, occupational and social mobility. The choice of a system of tax-financed social assistance, in preference to a system of social insurance financed out of contributions by employers and workers, was due to a combination of factors: the perceived need to provide immediate redress against poverty and unemployment (motivating the National Party); the powerful influence of left and liberal thinking from Britain, Australia and New Zealand (on both bureaucrats and the Labour Party); a concern that contributory schemes would add to much to the costs of production (among employers and workers alike); and a worry about the racial coverage of contributory schemes.
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Optimising partner matching for microsimulations of the HIV epidemic
(2015) Nathan, Geffen
Microsimulation is a way of modelling epidemics that is growing in popularity. Instead of the traditional way of building a model consisting of differential equations and then solving them, a microsimulation consists of, perhaps, thousands of agents, each representing a person, and each behaving according to a simple set of rules. Instead of outputs like infection and mortality rates being derived from equations, they are derived from the interactions of the agents over many iterations.
Open Access
Progress on application of ADAPT-VPA to minke whales in Areas IV and V given updated information from IDCR/SOWER and JARPA surveys
(2005) Mori, M; Butterworth, Doug S
The ADAPT-VPA assessment methodology of Butterworth et al. (1999) is applied to abundance estimates (from both IDCR/SOWER and JARPA surveys) and catch at age data (both commercial and scientific) for Areas IV and V. The methodology is extended to be able to take account of inter-annual differences in the distribution of the population between the two Areas when they are assessed jointly. An important feature of these updated results is that revised JARPA estimates of abundance are shown to be statistically comparable with estimates from the IDCR/SOWER programme (i.e. calibration factor not significantly different from 1). The general pattern shown by results is of a minke whale abundance trend that increased over the middle decades of the 20th Century to peak at about 1970, and then declined for the next three decades. The recruitment trend is similar, though with its peak slightly earlier. The factor to which the results are most sensitive is the value of natural mortality M. The assessments do show retrospective patterns, primarily related to changes in the best estimate of M as time has progressed. This in turn seems linked to the IDCR/SOWER survey trends suggesting higher, and the JARPA survey trends lower estimates of M. For the assessment of the two Areas combined, M is estimated at 0.068 with a CV of 0.12; this compares with CVs of typically 0.35 for the Area-specific assessments of Butterworth et al. (1999), which were based on eight seasons’ fewer data. The paper reflects an account of work in progress, and suggestions are made of areas where further analyses would be desirable.
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Progress on multi-species modeling in the Antarctic
(2005) Mori, M; Butterworth, Doug S
This paper introduces a multi-species predator-prey model of whales, seals and krill in the Antarctic that is currently in development, and illustrates some example results that are obtained from the model. Due to limited time, sensitivities of the output of the model to various input parameter values and functional response forms have not yet been investigated, and are planned for future work. Preliminary results show the possible role of predator-prey interactions in influencing the dynamics of the Antarctic species considered in the model.
Open Access
The quest for healing in South Africa's age of AIDS
(Taylor & Francis, 2006) Nattrass, Nicoli
Highly Active Antiretroviral Therapy (HAART) is the most effective means of extending the lives of people living with AIDS – yet only 25% of those in South Africa estimated to need it are receiving HAART. Those who cannot access HAART (or choose not to take it) may opt to use ‘traditional’ healing instead. Some people will do both. This article reviews the emerging South African literature exploring the interface between biomedical and traditional healing in this age of AIDS. It includes a discussion of recent relevant biographies and books. Particular attention is paid to the contrasting experiences of Edwin Cameron who took HAART and continues to live a productive life, and Fana Khaba, who rejected HAART in favour of untested substances. The paper notes how the diagnosis of AIDS as being caused by witchcraft may have psychological benefits (it shifts blame and responsibility to others) it can also exacerbate social tensions and undermine the health of those living with AIDS. It is argued that the state has an obligation to provide information to AIDS patients about the best scientifically tested medications.
Open Access
Social polarisation or professionalisation? Another look at theory and evidence
(2007) Borel-Saladin, Jacqueline; Crankshaw, Owen
The debate over whether or not the de-industrialisation of cities is accompanied by the occupational and income polarisation of their working populations has been characterised by some confusion over the relationship between incomes and occupations in the service sector. Specifically, many scholars have misunderstood the significance of middle-income service sector occupations for their interpretations of the post-industrial class structure of cities. Through a comparative study of de-industrialisation in Cape Town, we present evidence to show that the growth of service sector employment can, under specific conditions, produce a large middle-income occupational class of clerks, sales and personal services workers. The growth of this class can offset the decline of middle-income jobs caused by the loss of artisans, operatives and drivers in the declining manufacturing sector.
Open Access
Trading-off income and health: AIDS and the disability grant in South Africa
(Cambridge University Press, 2004) Nattrass, Nicoli
The number of disability grant recipients in South Africa is rising sharply, largely because of the AIDS pandemic. Now that the government is ‘rolling out’ antiretroviral treatment, many people living with AIDS stand to lose their grants as a result of restored health. Given South Africa’s high unemployment rates and lack of adequate welfare provision for the unemployed, those who do not find work will suffer a significant decline in income. They thus face a stark choice: to go on antiretroviral treatment and lose their disability grant, or avoid treatment and keep the grant for the rest of their (shorter) lives. Some may opt to start treatment, and then when the disability grant expires, discontinue their medication in order to become eligible once more for the disability grant. Such behaviour will foster drug resistance, thereby undermining the antiretroviral treatment rollout and exacerbating the AIDS pandemic. This is a direct consequence of a welfare system that does not provide support for the unemployed and that places poor people in a situation of having to choose between health and income. Replacing the disability grant with a basic income grant would help address the problem.
Open Access
Who consults sangomas in Khayelitsha? An exploratory quantitative analysis
(Taylor & Francis, 2006) Nattrass, Nicoli
This paper employs quantitative analysis to explore which people in Khayelitsha (an urban African community in Cape Town) are likely to be clients of ‘sangomas’, that is, traditional healers who specialise in divining illnesses usually perceived to be caused by witchcraft. It shows that sangoma clients are older, disproportionately female, poorer and less well educated than other people and that they are less trusting of others and more likely to believe in the efficacy of witchcraft. Being a recipient of a disability grant is the most significant predictor of whether the respondent is a sangoma client or not. The paper also discusses different quantitative sources for the use of traditional healers in South Africa, showing that the way the question is posed is all important

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