On the number of separable partitions

Consider partitions of a given set A of n distinct points in general position in ℝ ^d into parts where each pair of parts can be separated by a hyperplane that contains a given set of points E. We consider the problem of counting and generating all such partitions (correcting a classic 1967 result of Harding about the number of such partitions into two parts). Applications of the result to partition problems are presented.     

Mastery, Frequency, and Interaction of Managerial Behaviors Relative to Subunit Effectiveness

The relationships among mastery and frequency ofmanagerial behaviors, and subunit effectiveness havefrequently been confused. This study investigates bothmain and interactive effects. The results show that the interaction effect can often be thestrongest effect and that increasing frequency withoutimproving mastery can sometimes be detrimental.Furthermore, these results offer a possible explanation as to why research of managerial behavior hasbeen so inconclusive. In addition, the results questionpopular advice given often to managers. Finally, somerecommendations are made as to how management development could be made more effective basedon the results of this study.     

Are Individuals’ Desired Family Sizes Stable? Evidence from West German Panel Data

Using West German panel data constructed from the 1988 and 1994/1995 wave of the DJI Familiensurvey, we analyze the stability and determinants of individuals’ total desired fertility. We find considerable variation of total desired fertility across respondents and across interviews. In particular, up to 50% of individuals report a different total desired fertility across survey waves. Multivariate analysis confirms the importance of background factors including growing up with both parents, having more siblings, and being Catholic for preference formation. Consistent with the idea that life course experiences provide new information regarding the expected costs and benefits of different family sizes, the influence of background factors on total desired fertility is strong early in life and weakens as subsequent life course experiences, including childbearing, take effect. Accounting for unobserved individual heterogeneity, we estimate that an additional child may increase the total desired fertility of women with children by 0.14 children, less than what conventional estimates from cross-sectional data would have suggested.     

Entropy as a measure of centrality in networks characterized by path-transfer flow

Recently, Borgatti [Borgatti, S.P., 2005. Centrality and network flow. Social Networks 27, 55–71] proposed a taxonomy of centrality measures based on the way that traffic flows through the network—whether over path, geodesic, trail, or walk, and whether by means of transfer, serial duplication, or parallel duplication. Most of the extant centrality measures assume that traffic propagates via parallel duplication or, alternatively, that it travels over geodesics. Few of the other flow possibilities have centrality measures associated with them. This article proposes an entropy-based measure of centrality appropriate for traffic that propagates by transfer and flows along paths. The proposed measure can be applied to most network types, whether binary or weighted, directed or undirected, connected or disconnected. The measure is illustrated on the gang alliance network of Kennedy et al. [Kennedy, D.M., Braga, A. A., Piehl, A.M., 1998. The (un)known universe: mapping gangs and gang violence in Boston. Crime Prevention Studies 8, 219–262].     

Some spatial aspects of poverty in the USA

The social problem of poverty in the USA. has important spatial dimensions. The great migration of poor persons from the agricultural South to the industrial North shaped the nation's process of urbanization in the period after World War II. Subsequent suburbanization in the nation's cities was profoundly influenced by this movement and, in turn, had important implications for the urban poor. Also, the changing structure of employment opportunities within urban areas has had direct effects on the nature of the poverty problem in terms of spatial segregation and the persistence of poverty in urban areas. This paper offers a survey of the spatial aspects of poverty in the USA. and relates the problem of poverty to the forces of change that have contributed to the spatial transformation of the US economy.     

The Experience and Practice of Approved Social Workers in Northern Ireland

Correspondence to Dr Roger Manktelow, School of Social and Community Sciences, University of Ulster Magee College, Derry, BT48 7JL, Northern Ireland. Summary This article reports on the first extensive survey of ApprovedSocial Worker (ASW) activity under the Mental Health (NorthernIreland) Order 1986. The integrated health and social servicesorganizational structure, the adverse effects on individualmental health of the legacy of thirty years of civil conflictand the move from hospital to community care are significantfeatures which have influenced the delivery of mental healthsocial work services locally. The practice and experience ofASWs was surveyed by postal questionnaire and user and carerexperience of compulsory hospital admission was investigatedby a series of focus groups. The study revealed that two-thirdsof ASWs had experience of acting as an applicant in compulsoryhospital admission during the past two years. Nearly half (42per cent) of these ASWs had reported experience of between oneand five admissions and one-tenth had completed over twentyadmissions in the two-year period. In only a small minorityof cases did joint face-to-face assessment with the GeneralPractitioner (doctor) take place; nearly half of ASWs reporteddifficulties in obtaining transport; and only one-fifth of ASWshad experience of acting as a second approved social worker.Half of ASWs reported experience of guardianship, either asapplicant or in making the recommendation. Both service usersand carers reported a lack of understanding about the role ofthe ASW and complained about the lack of alternative resourcesthat ASWs could use to prevent hospital admissions. These findingsare discussed and a number of recommendations are proposed forimprovements to approved social worker practice.     

Why the Infinite Decision Puzzle is Puzzling

Pulier (2000, Theory and Decision 49: 291) and Machina (2000, Theory and Decision 49: 293) seek to dissolve the Barrett–Arntzenius infinite decision puzzle (1999, Theory and Decision 46: 101). The proposed dissolutions, however, are based on misunderstandings concerning how the puzzle works and the nature of supertasks more generally. We will describe the puzzle in a simplified form, address the recent misunderstandings, and describe possible morals for decision theory.     

Issue Framing and Citizen Apathy Toward Local Environmental Contamination

We adapt the frame-alignment perspective in order to demonstrate how institutional framing shapes media coverage of a toxic crisis. This framing activity is described as a new approach to managing public responses to contamination that differs from the approach characterizing contamination episodes at Love Canal and Woburn, MA. Our analysis focuses on the process by which actors responsible for managing toxic crises carefully construct and manage a coordinated risk frame. We refer to this as institutional framing and illustrate how it shapes media framing of a toxic event. We conclude by proposing further research to identify the causal relationship between institutional framing and the absence of mobilization.