Disaster response on September 11, 2001 through the lens of statistical network analysis

The rescue and relief operations triggered by the September 11, 2001 attacks on the World Trade Center in New York City demanded collaboration among hundreds of organisations. To shed light on the response to the September 11, 2001 attacks and help to plan and prepare the response to future disasters, we study the inter-organisational network that emerged in response to the attacks. Studying the inter-organisational network can help to shed light on (1) whether some organisations dominated the inter-organisational network and facilitated communication and coordination of the disaster response; (2) whether the dominating organisations were supposed to coordinate disaster response or emerged as coordinators in the wake of the disaster; and (3) the degree of network redundancy and sensitivity of the inter-organisational network to disturbances following the initial disaster. We introduce a Bayesian framework which can answer the substantive questions of interest while being as simple and parsimonious as possible. The framework allows organisations to have varying propensities to collaborate, while taking covariates into account, and allows to assess whether the inter-organisational network had network redundancy—in the form of transitivity—by using a test which may be regarded as a Bayesian score test. We discuss implications in terms of disaster management.     

Ethnic ingroup friendships in schools: Testing the by-product hypothesis in England,Germany, the Netherlands and Sweden

This study set out to examine to what extent ethnic ingroup friendship in secondary school classes are a by-product of cultural and socioeconomic ingroup friendship. Based on homophily theory, we expected similar opinions, leisure activities, religion, risk behaviour and socioeconomic factors to (partly) explain ethnic ingroup preferences. Multilevel p₂ models on 13,272 pupils in 625 secondary school classes in England, Germany, the Netherlands and Sweden showed that adolescents tend to have friends similar in ethnicity, cultural and socioeconomic characteristics. We find no evidence, however, that ethnic homophily is explained by cultural and socioeconomic homophily.     

Where do intra-organizational advice relations come from? The role of informal status and social capital in social exchange

Social status and social capital frameworks are used to derive competing hypotheses about the emergence and structure of advice relations in organizations. Although both approaches build on a social exchange framework, they differ in their behavioral micro-foundations. From a status perspective, advice giving is a means to generate prestige, whereas asking advice decreases one's relative standing. At a structural level these motivations are expected to result in an overrepresentation of non-reciprocal dyads and non-cyclical triadic structures in the advice network, as well as in active advice seekers being unlikely to be approached for advice, especially by active advice givers. From a social capital perspective, advice seeking creates obligations for the advice seeker. At the structural level, this results in an overrepresentation of reciprocal dyads and cyclical triads, and active advice seekers to be unpopular as targets of advice seeking, especially for active advice givers. Analyses of four waves of a longitudinal sociometric study of 57 employees of a Dutch Housing Corporation provide partial support for both approaches. In line with the social capital perspective, we find reciprocal advice relations to be overrepresented at the dyad level. Results at the triad level support the social status arguments, according to which high status individuals will avoid asking advice from low status individuals. The implications for macro-structural properties of intra-organizational advice network are discussed.     

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.     

Markets or networks: Households’ choice of financial intermediary in Western China

We argue that households’ choice of financial intermediary is conditioned by households’ social network structures and socioeconomic status. Analyses show that households’ social network size and network composition affect their choices by limiting the quality and quantity of information, resources, and social influence one can access through social ties. Moreover, we find that high-SES families favor formal intermediaries due not only to their richer financial knowledge, higher affordability, and greater capacity to repay loans, but also to their high demands and special types of financial needs that can hardly be satisfied by embedded resources.     

基于网络环境的研究生英语教学模式研究

传统的非英语专业研究生英语教学模式已不能适应为社会培养创新复合型人才的需要,对其进行改革势在必行。文章以建构主义学习理论和语言输入与输出理论为基础,构建了一种利用互联网资源辅助研究生英语课堂的教学模式,目的旨在提高非英语专业硕士研究生的英语交际能力。     

One step further from detected contradictions in a child welfare unit—a constructive approach to communicate the needs of social work when implementing ICT in social services

Unintended consequences were detected when a new client data system was taken into use in a child welfare unit in the City of Helsinki, the capital of Finland. This paper describes how social work was practiced during this period of change and analyses the phenomena involved. The concept of agency is central in the theoretical frame of this research. The data consist of written documents, participatory observation and the researcher's cooperation with the unit. Based on the data and by using the tools of semiotic sociology, the period of change was described in the form of four intersecting and parallel stories, each with a specific theme. These stories formed the basis for more theorising in which models of action theories were used. The results of this study showed that in the situation of inadequate human resource allocation for social work the data system took on a role of an agent. There was evidence of unintended consequences on the basic task in child welfare as the data system affected the work processes.     

Who are the active and central actors in the ‘rising civil society’ in Mexico?

The debate about the rise of civil society in Mexico suggests that the processes of political and economic liberalization are multiple and uneven and, thus, have different and contradictory effects on different social groups. This study takes such arguments into account and examines the nature of collective identities and social networks that are more likely to be mobilized in the rising civil society. Who, with what types of social networks and identities, are the active actors in this rising civil society in Mexico? This study also attempts to identify the central actors who take an active part in multi-sector coalitions. As such a broad coalition often leaves profound effects on politics and society, it is vital to ask which actors are likely to take an important step toward multi-sector coalition making. Using a catalog of 1797 protest campaigns collected from three Mexican newspapers between 1964 and 2000, event frequency analysis is employed to find active actors and social network analysis – blockmodel method and degree centrality measure – is applied to uncover central actors. The analyses reveal that while workers, peasants, or students continue to be very active, the centrality of these actors in contentious networks and coalitions has not increased. New central actors in the rising civil society turn out to be civic associations and NGOs formed around single issues, such as environment, retirement, and human rights. When a multi-sector coalition occurs in contemporary Mexico, NGOs and civic associations are likely to play a crucial role in it.