Panel unit root tests in the presence of cross-sectional dependence: finite sample performance and an application

This paper examines the finite sample properties of three testing regimes for the null hypothesis of a panel unit root against stationary alternatives in the presence of cross-sectional correlation. The regimes of Bai and Ng (2004), Moon and Perron (2004) and Pesaran (2007) are assessed in the presence of multiple factors and also other non-standard situations. The behaviour of some information criteria used to determine the number of factors in a panel is examined and new information criteria with improved properties in small-N panels proposed. An application to the efficient markets hypothesis is also provided. The null hypothesis of a panel random walk is not rejected by any of the tests, supporting the efficient markets hypothesis in the financial services sector of the Australian Stock Exchange.

Subsidy by Ascophyllum nodosum increases growth rate and survivorship of Patella vulgata

Limpets, predominantly Patella vulgata, have been associated with damaged or receding canopies of Ascophyllum nodosum. Although damage results from limpet grazing, the benefits that limpets gain from this behaviour are unclear as A. nodosum is thought to be well defended from grazers by anti-herbivore compounds. In the present study, R vulgata individuals were enclosed at densities between 80 and 320 m(-2) at 2 sites within Strangford Lough, Northern Island. Limpet growth and limpet survival were compared between unsubsidised controls and treatments in which limpet diets were subsidised by fronds of A. nodosum. When subsidised, limpet residual growth rates were significantly higher and mortality was lower than in unsubsidised control treatments. Individual limpets consumed a similar amount of A. nodosum regardless of limpet density. Higher densities of limpets, therefore, consumed more A. nodosum per replicate. The effects of A. nodosum in maintaining limpet densities could resonate through sheltered rocky communities. The importance of a macroalgal subsidy in supporting limpet populations may have been underestimated or overlooked in earlier studies. Therefore, the extensive and productive macroalgal canopies that characterise many sheltered temperate rocky shores could be more sensitive to increased limpet abundances than previously thought.

Sectarian and Nonsectarian Violence: Mothers' Appraisals of Political Conflict in Northern Ireland

Past research on peace and conflict in Northern Ireland has focused on politically motivated violence. However, other types of crime (i.e., nonsectarian) also impact community members. To study the changing nature of violence since the signing of the Belfast Agreement in Northern Ireland, we used a qualitative approach and the Constant Comparative Method to analyze focus group discussions with mothers from segregated Belfast neighborhoods. Participants articulated clear differences between sectarian and nonsectarian violence, and further distinguished sectarian violence along 2 dimensions—overt acts and perceived intergroup threat. Although both sectarian and nonsectarian antisocial behavior related to insecurity, participants described pulling together and increased ingroup social cohesion in response to sectarian incidents. The findings have implications for the study of violence and insecurity as experienced in the everyday lives of mothers, youth, and families in settings of protracted conflict.

The Development of Entrepreneurial Leadership: The Role of Human, Social and Institutional Capital

This paper contributes to the literature on entrepreneurial leadership development. Leadership studies are characterized by an increasing emphasis given to an individual leader's social and organizational domain. Within the context of human capital and social capital theory, the paper reflects on the emergence of a social capital theory of leadership development. Using a retrospective, interpretivist research method, the authors present the experience of a cohort of business leaders on an executive development programme to uncover the everydayness of leadership development in practice. Specifically, they explore how entrepreneurial leadership develops as a social process and what the role of social capital is in this. The findings suggest that the enhancement of leaders’ human capital only occurred through their development of social capital. There is not, as extant literature suggests, a clear separation between leader development and leadership development. Further, the analysis implies that the social capital theory of leadership is limited in the context of the entrepreneurial small firm, and the authors propose that it should be expanded to incorporate institutional capital, that is, the formal structures and organizations which enhance the role of social capital and go beyond enriching the human capital stock of individual leaders

Work-family characteristics as determinants of sickness absence: A large-scale cohort study of three occupational grades

This study examined the previously unexplored occupational grade-specific relationships of domestic responsibilities, the age of children, and work-family spillover, with registered sickness absence (>3 days' sick leave episodes, a mean follow-up of 17 months; n = 18,366 municipal employees; 76% women). The results showed that negative spillover from work into family life predicted a heightened rate of sickness absence spells among both women and men in all occupational categories (except upper white-collar men), but especially among blue-collar and lower white-collar employees. Furthermore, among all white-collar employees (except upper white-collar men), having young children (

The WR content of IC10 - first detection of WC9 stars in a low metallicity environment?

We present deep, narrow-hand photometry of the Local Group starburst galaxy IC10. Our dedicated photometric system provides detection of 13 new Wolf-Rayet (WR) stars and allows spectral subtypes to be assigned. Three of these new stars appear to be WC9 subtypes. If confirmed, these would be the very first WC9 stars ever detected in a low metallicity environment, hence putting strong new constraints on the formation and evolution models of massive stars. Eight of the new WR stars are of the WC subtype, which does not significantly modify the anomalously high WC/WN ratio in IC10. However it is likely that a number of Wolf-Rayet stars of the WNE and WC spectral subtypes are still to be discovered in the heart of the galaxy.