Analysis of variance for circular data

Over the last 25 years, increasing attention has been given to the problem of analysing data arising from circular distributions. The most important circular distribution was introduced by Von Mises (1918) which takes the form:

[Formulas]

where Io(k) is a modified Bessel function, u0 is the mean direction and k is the concentration parameter of the distribution. Watson & Williams (1956) laid the foundation of analysis of variance type techniques for the two-dimensional case of circular data using the Von Mises distribution. Stephens (1962a,b; 1969, 1972). Upton (1974) and Stephens (1982) made further improvements to Watson & Williams’ work. In this paper the authors will discuss the pitfalls of the methods adopted by Stephens (1982) and present a unified analysis of variance type approach for circular data.     

Median rankit control chart by the quantile approach

It is desirable that the data for a statistical control chart be normally distributed. However, if the data are not normal, then a transformation can be used, e.g. Box-Cox transformations, to produce a suitable control chart. In this paper we will discuss a quantile approach to produce a control chart and to estimate median rankit for various non-normal distributions. We will also provide examples of logistic data to indicate how a quantile approach could be used to construct a control chart for a non-normal distribution using a median rankit.     

Giving Up: How Gendered Organizational Cultures Push Mothers Out

Explanations for professional and managerial mothers' departure from paid work concentrate on childcare and women's preferences or choices. In contrast, our study, based on in‐depth interviews with professional and managerial mothers in London, shows that women's experiences within hegemonic masculine cultures play a key role. For example, working time norms require these mothers to work exceptionally long hours, to have permeable time boundaries even if they have negotiated reduced working hours and to ‘socialize’ in the evenings. Mothers are limited in their ability to protest or implement creative working time solutions because they feel they must hide their motherhood, which in itself creates tension. Mothers who are seemingly supported to work fewer hours are sidelined to lower‐status roles for which they are underpaid and undervalued in relation to their experience and previous seniority. Unless mothers mimic successful men, they do not look the part for success in organizations.     

Fitting a non-linear model with errors in both variables and its application *

Estimation of the parameters of a non-linear model is considered when both measured variables have random errors. The maximum likelihood estimates with the asymptotic variance and covariance matrix are presented. Real data are used to illustrate the procedure discussed.     

Social justice,care and developmental welfare in South Africa: a capabilities perspective

One of the paradoxes of the democratic project in South Africa is that the combination of political empowerment, organised constituencies of poor people and increasing social sector spending has made minimal impact on increasing equality. Despite an overall macroeconomic framework that emphasises fiscal restraint, social welfare spending has increased in the past 14 years, and dramatically so since 2003. Almost one in four South Africans receives some or other form of grant, and the majority of recipients are women. Indeed, South Africa is regularly described as the developing world’s largest and most generous welfare state. I address the extent to which gender inequalities are reduced through public sector spending, asking the question: what is the optimal relationship between social policy and the intrinsic democratic goals of equality, social justice and citizenship? Drawing on Amartya Sen’s capabilities approach, the article argues that a focus on social sector spending alone is inadequate to address questions of social justice. Instead, I draw attention to the normative assumptions, discursive environment and institutional context in which social policy is elaborated and implemented. I argue that, in a context in which there is relatively poor infrastructural capacity in the state to ensure that service delivery takes place in fair, consistent and egalitarian ways, households and communities act as shock absorbers of state failures and women’s gendered burdens increase, despite formal commitments to gender equality. While women appear to have gained from political empowerment, women politicians did not effectively leverage their position in the state to promote pro‐poor policies or to build coalitions to challenge the watering down of early commitments to reducing gender inequalities.     

Poverty as a System: Human Contestability Approach to Poverty Measurement

Since Sen's (1976) paper on poverty measurement, a substantial literature, both theoretical and empirical, has emerged. There have been several recent efforts to drive poverty measures based on different approaches and axioms. These poverty indices are based on head count ratio, poverty gaps and distribution of income. These are very narrow in approach and suffer from several drawbacks. However, the purpose of the present paper is to introduce a new poverty measure based on a holistic and system modelling approach. Based on Chopra's human contestability (Chopra, 2003, 2007) approach to poverty, this new approach to measuring poverty has been developed using a structure equation model based on Kanji's business excellence model (Kanji, 2002) to create the proposed poverty model. We construct a latent variable structural equation model to measure the contestability excellence within certain boundaries of the societal system. It will provide us with a measurement of poverty in a society or community in terms of human contestability. A higher human contestability index will indicate the lower poverty within the society. Strengths and weakness as of various components will also indicate that a characteristic of the individual requires extra society or government support to remove poverty. However, there remains considerable disagreement on the best way to achieve this.