Generalized simultaneous confidence regions for regression coefficients and their ratios

This study constructs a simultaneous confidence region for two combinations of coefficients of linear models and their ratios based on the concept of generalized pivotal quantities. Many biological studies, such as those on genetics, assessment of drug effectiveness, and health economics, are interested in a comparison of several dose groups with a placebo group and the group ratios. The Bonferroni correction and the plug-in method based on the multivariate-t distribution have been proposed for the simultaneous region estimation. However, the two methods are asymptotic procedures, and their performance in finite sample sizes has not been thoroughly investigated. Based on the concept of generalized pivotal quantity, we propose a Bonferroni correction procedure and a generalized variable (GV) procedure to construct the simultaneous confidence regions. To address a genetic concern of the dominance ratio, we conduct a simulation study to empirically investigate the probability coverage and expected length of the methods for various combinations of sample sizes and values of the dominance ratio. The simulation results demonstrate that the simultaneous confidence region based on the GV procedure provides sufficient coverage probability and reasonable expected length. Thus, it can be recommended in practice. Numerical examples using published data sets illustrate the proposed methods.     

Evaluating social exclusion interventions in university-community partnerships

Most university-community partnerships (UCPs) involve elements of community-level social exclusion interventions. As such, they face substantial challenges in management and evaluation. This paper highlights the central challenges associated with evaluation of UCP and other social exclusion interventions at the community level, and suggests methods to overcome them. The main body of the paper presents a case study based on a four-year action research involving evaluation of a social exclusion intervention initiated and implemented by a UCP in Israel. The case study highlights the challenges faced by the evaluation team, the solutions provided, and the contribution of the evaluation to improvement and accountability.     

Beyond interviewer effects in the standardized measurement of ego-centric networks

The effects which interviewers exert on the collection of ego-centric networks have recently come into the focus of methodological considerations. Studies consistently show that the size of networks varies depending on the interviewer. We would like to expand on this research strand by pointing to different aspects which have so far gone unremarked in the discussion. First, size is mainly analysed as a network measure which is influenced during data collection, while other common measures such as network density or composition have not received sufficient consideration. Second, large-scale surveys using face-to-face interviews usually allocate interviewers to a single sampling point. Differences between sampling points (locality effects) are attributed to interviewer effects. Hence, we disentangle the effects of the locality and interviewer. Third, the discussion on interviewer effects often follows an “actor-oriented” consideration of how data collection situations are structured by interviewers. Expanding this approach from a relational perspective, we consider the relationship between the interviewers and respondents and whether this relationship influences the collection of network data. To test our hypotheses about the influence of interviewers, the locality and the interviewer-respondent relationship on different network measures, we use data from the 2010 German General Social Survey (n = 2827 respondents, n = 220 interviewers). The multilevel analyses show that the relationship between the interviewer and the respondent is not very relevant. Furthermore, the analyses show that interviewers have an influence on the network size but not on measures of their composition. However, evidence on the prevalence of locality or interviewer effects is mixed. Finally, homophilous interviewer-respondent relationships have very little effect on network characteristics. We find evidence of training and fatigue effects on network size. However, much of the variation in network size caused by the interviewer still remains unexplained. We draw conclusions on how to organize interview situations in surveys.     

Investor commitment to serial entrepreneurs: A multilayer network analysis

Social networks are complex systems composed of interdependent organizations and people with diverse network structures. Understanding network dynamics, such as exchange commitment, requires a methodological toolkit that does not assume away complexity. In this study, we extend a technique for analyzing longitudinal, multilayer network data called network alignment. We introduce a novel metric – intersect proportions – for analyzing similarity between divergent graphs. We demonstrate the application of network alignment and intersect proportions to the context of investor commitment to startups and entrepreneurs. Using this technique, we are able to disentangle exchange commitment across complex networks.     

Are Hearing Voices Networks Compatible with Cognitive Behavioural Therapy for Psychosis?

The most extensively evaluated intervention for auditory hallucinations is Cognitive Behavioural Therapy for Psychosis (CBTp), which is usually delivered in statutory settings by experienced clinicians. In contrast, peer support networks, such as the Hearing Voices Network (HVN), operate informally using peers to normalise and manage voices. This article compares these two approaches to identify points of synergy and difference. Its analysis suggests the two approaches share many features, but also deviate in important ways that could compensate for each other. Instead of competing with each other as might first be thought, they may actually be complementary. Further, HVN may align comfortably with the values and principles of social work. Social workers seeking to engage with voice hearers may be advised to study the underlying principles of each approach to guide the way in which they can capitalise on intervention opportunities to better assist voice hearers.     

The efficiency of mutual fund companies: Evidence from an innovative network SBM approach

This paper is the first DEA (Data Envelopment Analysis) evaluation of the efficiency of a sample of mutual fund companies in a large Euro fund industry, i.e. Spain. Our novel network model links the efficiency of the core activities (portfolio management and marketing/distribution) of a mutual fund company to the efficiency of its operational management function. Our results highlight the important networking effects at the marketing stage and question the prime role of portfolio management skills in the overall efficiency of a mutual fund company. The evaluation of robust efficiency clusters indicates that the efficiency rankings obtained with our network model persist significantly along our sample period. Finally, the application of the SBM (Slacks-Based Measure) Variation III to our network model allows us to identify a large number of globally inefficient but locally efficient companies with reference to competitors with similar management resources.     

Muslim–Christian Relations in Kupang: Negotiating Space and Maintaining Peace

Kupang, the capital city of Nusa Tenggara Timur (NTT/East Nusa Tenggara) province, is a majority Christian community in predominantly Muslim Indonesia. Despite widespread inter-religious violence in Indonesia, especially around the fall of the Suharto regime in 1998, Muslim–Christian relations in Kupang have, to date, been relatively harmonious. Minor incidents occurred in 1998 and tensions were exacerbated by the construction of a new mosque at Batuplat village in 2011, but these did not lead to larger conflicts. Drawing on observations in three urban neighbourhoods (Kampung Solor, Airmata and Oesapa), this article discusses the experiences of Muslims in these urban neighbourhoods in negotiating space for their religious practices and maintaining peace with their Christian neighbours. This ethnographic study allows us to understand factors underpinning inter-religious harmony in Kupang.     

Residential mobility and the spatial dispersion of personal networks: Effects on social support

Using a representative national sample of personal networks, this article explores how the spatial dispersion of networks, residential mobility and social support are linked. Three issues will be addressed here. Firstly, how is the spatial dispersion of personal networks related to individuals’ social characteristics, network composition and residential mobility? Secondly, how do the spatial dispersion of networks, residential mobility and their combined effect influence the number and (thirdly) the structure of emotional support ties? Results showed that the extent of the support was affected neither by the geographical distribution of the networks nor by residential mobility. Living far from one's birthplace, however, exerted two distinct, and opposite effects on the support network structure. On the one hand, mobility led to high spatial dispersion of personal contacts, which in turn favored a sparsely knit network centered around the mobile individual. On the other hand, by controlling for the effect of distance between the contacts, we found that individuals that cited long-distance ties tended to be part of more transitive support networks than those that cited local ties. We interpreted the latter effect as evidence that transitive ties may survive greater spatial distances than intransitive ones. These findings are discussed in view of spatial mobility and social network research.     

Random errors in egocentric networks

The systematic errors that are induced by a combination of human memory limitations and common survey design and implementation have long been studied in the context of egocentric networks. Despite this, little if any work exists in the area of random error analysis on these same networks; this paper offers a perspective on the effects of random errors on egonet analysis, as well as the effects of using egonet measures as independent predictors in linear models. We explore the effects of false-positive and false-negative error in egocentric networks on both standard network measures and on linear models through simulation analysis on a ground truth egocentric network sample based on facebook-friendships. Results show that 5–20% error rates, which are consistent with error rates known to occur in ego network data, can cause serious misestimation of network properties and regression parameters.     

Producing public goods in networks: Some effects of social comparison and endogenous network change

As actors participate in the production of public goods, processes of social comparison may affect the decisions about the individual contributions as well as the endogenously changing structure of an underlying social network. This leads to the transformation of an ordinary n-player Prisoner's Dilemma of collective action into an n-player coordination game. The paper uses agent-based simulations to trace the formation of public goods while varying network characteristics, such as density, segregation, or the strength of relationships. Additionally, the usage of both a forward- and a backward-looking agent model shows possible implications of different assumptions about the actors’ decision making.