Multilevel Latent Class Models

The latent class (LC) models that have been developed so far assume that observations are independent. Parametric and nonparametric random–coefficient LC models are proposed here, which will make it possible to modify this assumption. For example, the models can be used for the analysis of data collected with complex sampling designs, data with a multilevel structure, and multiple–group data for more than a few groups. An adapted EM algorithm is presented that makes maximum–likelihood estimation feasible. The new model is illustrated with examples from organizational, educational, and cross–national comparative research.     

Micro‐ and Macrolevel Determinants of Women's Employment in Six Arab Countries

We analyzed determinants of women's employment with data for 40,792 women living in 103 districts of 6 Arab countries. We tested a new theoretical framework that addresses the roles of needs, opportunities, and values at multiple levels. At the microlevel (individual, family), socioeconomic factors, care duties, and traditionalism were important; at the macrolevel (district), economic development and societal norms were important. Women's education seemed most influential. Interaction analyses showed that returns on women's education depended on their partner's education and on the economic development, labor market structure, urbanization, and strength of traditional norms in the district in which women live. Our results stress the importance of a comprehensive approach toward women's employment in these countries.     

NUSAP Method for Evaluating the Data Quality in a Quantitative Microbial Risk Assessment Model for Salmonella in the Pork Production Chain

The numeral unit spread assessment pedigree (NUSAP) system was implemented to evaluate the quality of input parameters in a quantitative microbial risk assessment (QMRA) model for Salmonella spp. in minced pork meat. The input parameters were grouped according to four successive exposure pathways: (1) primary production (2) transport, holding, and slaughterhouse, (3) postprocessing, distribution, and storage, and (4) preparation and consumption. An inventory of 101 potential input parameters was used for building the QMRA model. The characteristics of each parameter were defined using a standardized procedure to assess (1) the source of information, (2) the sampling methodology and sample size, and (3) the distributional properties of the estimate. Each parameter was scored by a panel of experts using a pedigree matrix containing four criteria (proxy, empirical basis, method, and validation) to assess the quality, and this was graphically represented by means of kite diagrams. The parameters obtained significantly lower scores for the validation criterion as compared with the other criteria. Overall strengths of parameters related to the primary production module were significantly stronger compared to the other modules (the transport, holding, and slaughterhouse module, the processing, distribution, and storage module, and the preparation and consumption module). The pedigree assessment contributed to select 20 parameters, which were subsequently introduced in the QMRA model. The NUSAP methodology and kite diagrams are objective tools to discuss and visualize the quality of the parameters in a structured way. These two tools can be used in the selection procedure of input parameters for a QMRA, and can lead to a more transparent quality assurance in the QMRA.     

Does Circular Migration Lead to “Guest Worker” Outcomes?

At first at the level of the European Commission, and increasingly also in the European Union’s member states, it is being recognized that past labour migration management tools have more or less serious drawbacks in that they produce undesired outcomes and do not sufficiently attain the objectives for which they were designed. The welfare states of north‐western Europe are discovering that their desire of the past three decades to restrict labour immigration as much as possible is no longer “in sync” with changing labour market demands, which are growing both for the highly skilled and the unskilled. In order to satisfy the demand for unskilled labour, schemes are being proposed that would allow for circular migration. The European Commission is a forceful promoter of these schemes. Member states such as the Netherlands, which we take as a case in point, are also considering modes by which to allow temporary unskilled labour migration, but seem intent on employing regulatory tools that are not very different from those used in the “guest worker” era, which brought about large‐scale settlement. Up to the present time, the resulting ethnic minority groups are the subject of large integration efforts on the part of the receiving states. This begs the question of the extent to which “circular migration” would be different from “guest worker” schemes, in its management and its outcomes.     

Changing Industrial Metabolism: Methods for Analysis

Research in the field of industrial metabolism traditionally has been focused on measuring and describing physical flows of economic systems. The metabolism of economic systems, however, changes over time, and measuring material flows is insufficient to understand this process. Understanding the relation between economic activities and material flows can help to unravel the socio-economic causes of these physical flows. Three issues are addressed: The importance of spatial scales and trade flows, empirical analysis of relations between economic development and material flows, and treatment of behaviour of and interactions between stakeholders. For each of these issues, methods for analysis are suggested.     

Friendship and Alcohol Use in Early Adolescence: A Multilevel Social Network Approach

This study applies multilevel social network analytic techniques to examine processes of homophilic selection and social influence related to alcohol use among friends in early adolescence. Participants included 3,041 Dutch youth (M age =12 years, 49% female) from 120 classrooms in 14 schools. Three waves with 3‐month intervals of friendship nomination data and self‐reports of drinking behavior were collected. Results revealed that within classrooms, friendship nominations tended to be reciprocated and dyadic friendships tended to be embedded within cohesive subgroups (e.g., cliques). Students tended to nominate friends who were the same sex, from a similar ethnic background, and who they previously knew from primary school. Selection processes turned out to play a more significant role than social influence processes in predicting similarity between early adolescent friends' alcohol use. Although friendship dynamics and individual drinking trajectories substantially differed between classrooms, the effects of homophilic selection and social influence did not.     

The ‘Dark Side’ of Social Capital: A Cross-National Examination of the Relationship Between Social Capital and Violence in Africa

Social Indicators Research - Research and policy circles often emphasize the importance of social capital in achieving social transformation and economic development. There is also, however,...