Generalized blockmodeling of valued networks

The paper presents several approaches to generalized blockmodeling of valued networks, where values of the ties are assumed to be measured on at least interval scale. The first approach is a straightforward generalization of the generalized blockmodeling of binary networks [Doreian, P., Batagelj, V., Ferligoj, A., 2005. Generalized Blockmodeling. Cambridge University Press, New York.] to valued blockmodeling. The second approach is homogeneity blockmodeling. The basic idea of homogeneity blockmodeling is that the inconsistency of an empirical block with its ideal block can be measured by within block variability of appropriate values. New ideal blocks appropriate for blockmodeling of valued networks are presented together with definitions of their block inconsistencies.     

Privatisation Effects: Some Evidence from Serbia

This paper analyses basic outcome and effects of the privatisation process in Serbia. The first two parts of the paper deal with general achievements of the newest privatisation plan adopted in 2001. We present a brief background of the results of the privatisation process, analysing changes in the structure of enterprises by ownership status, the number of privatised firms, revenues earned through privatisation, the rate of successful transactions, and other relevant privatisation indicators. The paper continues with an analysis of a survey conducted within a sample of Serbian enterprises offering some evidence about performance, competition, and restructuring within different types of firms: socially owned, privatised, and new private. Contrary to the broadly accepted statement that new private firms are leading in transition economies, according to our estimation of the effects of the ownership type on firm performance, it appears that the privatised sector seems to be more active. A comparison of the survey results with findings for three neighbouring countries indicates that there is no general conclusion about the way how ownership status of a firm affects its performance in a transition economy. Although conclusions drawn from our survey analysis should be regarded as preliminary and limited by the quality of survey data and could not be generalised for the privatisation process in other transition countries, the findings we present, including the comparison made with other economies, could contribute to the understanding of both privatisation effects in general and effects remarkable for the Serbian economy.      

Serbian Judiciary and Transition: Recent Jurisprudence

This article examines the role and position of national courts during transitional periods with focus on and case study of the judiciary in Serbia. Courts in Serbia, as any other judiciary in transition, have undergone a staggering transformative process as illustrated by a chronology of human rights cases. On the other hand, courts in Serbia, as their counterparts worldwide, have also been the transformation force, as evidenced by recent jurisprudence in cases dealing more or less successfully with political assassinations, organized crime, corruption, war crimes, and international courts.     

Diathesis stress or differential susceptibility? testing longitudinal associations between parenting,temperament, and children's problem behavior

In this study we investigated longitudinal associations among parenting, children's temperamental negative affectivity, and internalizing and externalizing behavior. Second, we tested whether findings confirmed the diathesis‐stress model or differential susceptibility theory when conducting stringent interaction tests. The sample included 129 children and their families. Parenting quality (age 5) was measured by parent–child interaction observations. Parents evaluated child negative affectivity (age 7) and teachers reported on problem behavior (age 12). Multiple regression analyses revealed an interaction effect of negative affectivity and parenting on externalizing behavior. Visual inspection suggested ‘for better and for worse’ effects of parenting for children with negative affectivity. However, more stringent tests failed to show convincing evidence for differential susceptibility theory. For internalizing behavior, negative affectivity may render children vulnerable regardless of parenting. Our results point at the importance of further testing interaction effects to distinguish between differential susceptibility theory and the diathesis‐stress model.     

Facilitating labour migration from Latvia: strategies of various categories of intermediaries

ABSTRACT

Within the broad category of migration industries, we focus on intermediaries between employers in Norway requiring migrant labour, and suppliers of Latvian workers willing to migrate. Mediation of labour power is a regulated domain in both countries, but regulations may change: regulations in Latvia have become more lenient, whereas in Norway, they have become stricter in response to increased migration. Intermediaries must be responsive to fluctuations in labour supply and demand, as well as to changing regulations. Today, destination countries are experiencing an overabundance of available migrant labour. This buyer’s labour market represents a challenge for intermediaries, spurring adjustments and side-stepping of regulations. Formal temp agencies are supplemented by informal ones, challenging the conceptualisation of intermediaries. Also work migrants may become agents, shaping new forms of intermediation and expanding the concept of ‘migration industry’ to encompass facilitation of labour migration through social networks. In this article, we construct typologies inductively, establishing categories meaningful in the complex context of labour migration from Latvia to Norway. We distinguish between mediation through formal versus informal agencies, establish characteristics of agencies versus individual social network-based mediation and discuss mediation through the posting of workers by companies.     

Broadcasting multiple messages in the 1-in port model in optimal time

In the 1-in port model, every vertex of a synchronous network can receive at most one message in each time unit. We consider simultaneous broadcasting of multiple messages from the same source or from distinct sources in such networks with an additional restriction that every received message can be sent out to neighbors only in the next time unit and never to already informed vertex. We use a general concept of level-disjoint partitions developed for this scenario. Here we introduce a subgraph extension technique for efficient spreading information within this concept. Surprisingly, this approach with so called biwheels leads to simultaneous broadcasting of optimal number of messages on a wide class of graphs in optimal time. In particular, we provide tight results for bipartite tori, meshes, hypercubes, Knödel graphs, circulant graphs. We also propose several open problems and conjectures.     

Comparison of efficiencies of some symmetry tests around an unknown centre

In this paper, some recent and classical tests of symmetry are modified for the case of an unknown centre. The unknown centre is estimated with its α-trimmed mean estimator. The asymptotic behaviour of the new tests is explored. The local approximate Bahadur efficiency is used to compare the tests to each other as well as to some other tests.     

Non-response in social networks: The impact of different non-response treatments on the stability of blockmodels

Discerning the essential structure of social networks is a major task. Yet, social network data usually contain different types of errors, including missing data that can wreak havoc during data analyses. Blockmodeling is one technique for delineating network structure. While we know little about its vulnerability to missing data problems, it is reasonable to expect that it is vulnerable given its positional nature. We focus on actor non-response and treatments for this. We examine their impacts on blockmodeling results using simulated and real networks. A set of ‘known’ networks are used, errors due to actor non-response are introduced and are then treated in different ways. Blockmodels are fitted to these treated networks and compared to those for the known networks. The outcome indicators are the correspondence of both position memberships and identified blockmodel structures. Both the amount and type of non-response, and considered treatments, have an impact on delineated blockmodel structures.     

Supporting the Caliph's Project: Bosnian Muslims and the Hejaz Railway

This article will analyse Bosnian Muslims response and contribution to the construction of the Hejaz Railway. Based on primary sources during the 1900–1908 period, the article will argue that Bosnian Muslims actively followed news about the progress of the railway and financially contributed to its construction. Bosnian Muslim contribution took the form of establishing committees for the collection of voluntary donations in a number of Bosnian towns in 1905 and 1906. The active involvement of Bosnian Muslims in the construction of the Hejaz Railway shows that the spiritual bonds between Bosnian Muslims living in Austria-Hungary and their Caliph in Istanbul were not completely severed by the Austro-Hungarian occupation of Bosnia in 1878. Following a brief survey of Bosnian Muslim history within the Austro-Hungarian Empire, the article describes the Hejaz Railway project and surveys the Bosnian Muslim contribution to the project.