5,531 research outputs found

    China, South Africa and the Lewis Model

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    The paper uses the Lewis model as a framework for examining the labour market progress of two labour-abundant countries, China and South Africa, towards labour shortage and generally rising labour real incomes. In the acuteness of their rural-urban divides, forms of migrant labour, rapid rural-urban migration, and high and rising real wages in the formal sector, the two economies are surprisingly similar. They differ, however, in the dynamism of their formal sector growth of output and employment, and in the growth of their labour forces. Whereas China - a labour-surplus economy par excellence despite unemployment until recently taking only a disguised form - is moving rapidly in the direction of labour scarcity, South Africa which historically has been short of labour - is moving towards increased labour surplus in the form of open unemployment. The paper draws on research previously conducted by the author in separate research projects on the two countries.China; South Africa; Lewis model; wages; labour supply; rural-urban migration; unemployment

    Development of a software safety process and a case study of its use

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    The goal of this research is to continue the development of a comprehensive approach to software safety and to evaluate the approach with a case study. The case study is a major part of the project, and it involves the analysis of a specific safety-critical system from the medical equipment domain. The particular application being used was selected because of the availability of a suitable candidate system. We consider the results to be generally applicable and in no way particularly limited by the domain. The research is concentrating on issues raised by the specification and verification phases of the software lifecycle since they are central to our previously-developed rigorous definitions of software safety. The theoretical research is based on our framework of definitions for software safety. In the area of specification, the main topics being investigated are the development of techniques for building system fault trees that correctly incorporate software issues and the development of rigorous techniques for the preparation of software safety specifications. The research results are documented. Another area of theoretical investigation is the development of verification methods tailored to the characteristics of safety requirements. Verification of the correct implementation of the safety specification is central to the goal of establishing safe software. The empirical component of this research is focusing on a case study in order to provide detailed characterizations of the issues as they appear in practice, and to provide a testbed for the evaluation of various existing and new theoretical results, tools, and techniques. The Magnetic Stereotaxis System is summarized

    Race and the Incidence of Unemployment in South Africa

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    South Africans unemployment rate is one of the highest in the world, and it has important distributional implications. The paper examines the incidence of unemployment using two national household surveys for the mid-1990s. Both entry to unemployment and the duration of unemployment are examined. A probit model of the determinants of unemployment is estimated: it shows an important role for race, education, age, gender, home-ownership, location, and numerous other variables, all of which have plausible explanations. The large race gap in unemployment is explored further by means of a decomposition analysis akin to that normally used to analyse wage discrimination. There remains a substantial residual that cannot be explained by observed characteristics, and which might represent unobserved characteristics, such as quality of education, or discrimination. Implications for policy and for research are drawn.Unemployment, South Africa, racial discrimination

    The Nomenclatural Status of Saperda Inordata Say (Coleoptera: Cerambycidae)

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    Excerpt: Confusion as to the identity and proper name of our common Saperda on trembling aspen, Populus tremuloides Michaux, in eastern North America should be clarified. The confusion has arisen from three reasons: (1) LeConte failed to distinguish S. concolor Lec. (1852) from S. irornata Say (1824); (2) Say\u27s type material was destroyed or lost which makes verification impossible; and (3) S. inornata varies from light to dark in overall appearance. The former two points are discussed here and the latter will be covered in a separate article. Authors since LeConte\u27s time have used a variety of binominal and trinominal designations for this species. In 1924 J. 0. Martin suggested that the name inornata, which had been placed in the Genus Mecas, really belonged in the Genus Saperda and that S. inornata should be reinstated replacing LeConte\u27s concolor which Martin, followed by Breuning (1952), considered a synonym of inornata. Despite Martin\u27s suggestion, S. concolor is in common use today. However, a search of the literature produced evidence which substantiates Martin\u27s claim that inornata must stand (Nord, 1968). A summary of this search is presented here in detail and a neotype has been proposed so that the nomenclature will be stabilized (Nord and Knight, 1970)

    The Geographic Variation of Saperda Inornata Say (Coleoptera: Cerambycidae) in Eastern North America

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    Excerpt: During the summers of 1962 and 1963 a study of the life history and behavior of what was thought to have been Saperda moesta LeConte in trembling aspen, Populus tremuloides Michaux, was completed in northern Michigan (Nord, 1968). After the field study, it became apparent that the original identification was doubtful. Furthermore, there was a possibility that two species were present in the study areas, thus the biological data collected may have represented not one but two species

    The Labour Market Mobility of Polish Migrants: A Comparative Study of Three Regions in South Wales, UK

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    Since Polish migrants began entering the UK labour market in the post-accession period, there has been a significant amount of case study research focusing on the impact of this large migrant group on the UK economy. However, ten years after enlargement, there is still insufficient information regarding the labour market mobility of Polish migrants residing in the UK for the longer term. The available research on this topic is largely concentrated in urban settings such as London or Birmingham, and does not necessarily capture the same patterns of labour market mobility as in non-urban settings. Using qualitative data collected in three case study locations – urban, semi-urban and rural – in the South Wales region from 2008–2012, this article has two main aims. First, given the proximity of the case study locations, the article highlights the diversity of the Polish migrant characteristics through the samples used. Second, using trajectories created from the data, this article compares the variations among the labour market movements of the Polish migrants in each sample to determine what characteristics influence labour market ascent. Through this comparative trajectory analysis, the findings from this article point to the relative English language competency of migrants as the primary catalyst for progression in the Welsh labour market across all three case study regions. The secondary catalyst, which is intertwined with the first, is the composition of the migrants’ social networks, which enable, or in some cases disable, labour market progression. These findings have significant implications in the national and in the supranational policy sphere regarding the employment of migrants as well as their potential for cultural integration in the future

    Continuous Empirical Characteristic Function Estimation of Mixtures of Normal Parameters

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    This paper develops an e±cient method for estimating the discrete mix- tures of normal family based on the continuous empirical characteristic function (CECF). An iterated estimation procedure based on the closed form objective distance function is proposed to improve the estimation effciency. The results from the Monte Carlo simulation reveal that the CECF estimator produces good finite sample properties. In particular, it outperforms the discrete type of methods when the maximum likelihood estimation fails to converge. An empirical example is provided for illustrative purposes.Empirical characteristic function; Mixtures of normal.
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