Structure Learning of Contextual Markov Networks using Marginal Pseudo‐likelihood

Markov networks are popular models for discrete multivariate systems where the dependence structure of the variables is specified by an undirected graph. To allow for more expressive dependence structures, several generalizations of Markov networks have been proposed. Here, we consider the class of contextual Markov networks which takes into account possible context‐specific independences among pairs of variables. Structure learning of contextual Markov networks is very challenging due to the extremely large number of possible structures. One of the main challenges has been to design a score, by which a structure can be assessed in terms of model fit related to complexity, without assuming chordality. Here, we introduce the marginal pseudo‐likelihood as an analytically tractable criterion for general contextual Markov networks. Our criterion is shown to yield a consistent structure estimator. Experiments demonstrate the favourable properties of our method in terms of predictive accuracy of the inferred models.     

Bayesian variable selection with strong heredity constraints

In this paper, we propose a Bayesian variable selection method for linear regression models with high-order interactions. Our method automatically enforces the heredity constraint, that is, a higher order interaction term can exist in the model only if both of its parent terms are in the model. Based on the stochastic search variable selection George and McCulloch (1993), we propose a novel hierarchical prior that fully considers the heredity constraint and controls the degree of sparsity simultaneously. We develop a Markov chain Monte Carlo (MCMC) algorithm to explore the model space efficiently while accounting for the heredity constraint by modifying the shotgun stochastic search algorithm Hans et al. (2007). The performance of the new model is demonstrated through comparisons with other methods. Numerical studies on both real data analysis and simulations show that our new method tends to find relevant variable more effectively when higher order interaction terms are considered.     

Voluntary Associations and Net Fertility During the Swedish Demographic Transition

This study investigates the role of changing social relations for fertility decline during the European fertility transition. The growth of voluntary associations at the end of the nineteenth century entailed a radical shift in the landscape of social relations in Sweden. By combining micro-census data from 1890 to 1900 with local-level membership data for three voluntary association groups, this article assesses the effect of parish-level voluntary association size on net fertility in Sweden using mixed-effects Poisson regression models. The results show that the adoption of fertility limitation during the transition period was associated with the creation and diffusion of the idea of respectability within large social network organisations, an idea that has previously been shown to be connected to fertility limitation. Furthermore, by applying a social network perspective, the results show that the strength of the effect was dependent on the structure of the social networks in terms of size, density, and homogeneity. Voluntary association size had the strongest effect for the free churches, which created dense heterogeneous networks through systems of social control, while the size of the temperance association showed no effect on fertility because the connections between nodes were sparse.     

Christian democracy, social democracy and the paradoxes of earnings-related social security

This article compares the retirement policies of Belgium and Sweden in order to reveal the different incentive structures built into the pensions systems prevailing in countries that are taken to represent different approaches to welfare capitalism. It addresses the question of why in a Christian Democratic welfare state that is said to grant pensions rights on the basis of merit and past work performance one can find extremely low labour-force participation rates among elderly workers, while in a Social Democratic welfare state that is supposed to grant pension rights relatively independent of past labour-market performance, one can find quite high participation rates amongst that section of the labour force. This apparent paradox is explained in terms of the different purposes of the early-retirement schemes in the two countries: in Belgium they were primarily part of a strategy to combat (youth) unemployment, in Sweden they had more to do with reforms that sought to accomplish a 'humanisation of work' by softening the abrupt transition from work into retirement.     

Academic writing as autocommunication – the case of doctoral dissertations on CSR

In this article, we explore the self‐oriented rather than socially‐oriented reasons why a doctoral dissertation in the field of corporate social responsibility (CSR) is written. We base our article on Yuri M. Lotman’s idea on autocommunication which we use as tool in analysing a group interview conducted with six doctoral students studying in the field of CSR. We suggest that autocommunicational aspects might play a much more important role in rationalized Western culture and science than is often realized, and our main thesis is that one essential reason for writing a doctoral dissertation in the field of CSR might be to communicate with oneself and that this even might contain a therapeutic dimension. Implications for students, supervisors and future research are discussed at the end of the article.     

Putting Ecstasy to Work: Pleasure,Prostitution, and Inequality in the Indonesian Borderlands

This article takes the drug Ecstasy as a commodity located at the center rather than at the margins of social processes, a technology that allows for the temporary engagement with pleasure and displacement of inequality in the context of nightlife and prostitution. It addresses these issues by focusing ethnographic attention on how Indonesian female prostitutes and their Singaporean male clients use Ecstasy in a disco on the Indonesian island of Batam, an export-processing zone located at the border to Singapore. By paying close attention to consumption practices, the article uses Ecstasy as a starting point for illuminating intersections of social mobility and inequality in the context of contemporary forms of transnational capitalism.     

A Risk Management Procedure for the Washington State Ferries

The state of Washington operates the largest passenger vessel ferry system in the United States. In part due to the introduction of high-speed ferries, the state of Washington established an independent blue-ribbon panel to assess the adequacy of requirements for passenger and crew safety aboard the Washington state ferries. On July 9, 1998, the Blue Ribbon Panel on Washington State Ferry Safety engaged a consultant team from The George Washington University and Rensselaer Polytechnic Institute/Le Moyne College to assess the adequacy of passenger and crew safety in the Washington state ferry (WSF) system, to evaluate the level of risk present in the WSF system, and to develop recommendations for prioritized risk reduction measures, which, once implemented, can improve the level of safety in the WSF system. The probability of ferry collisions in the WSF system was assessed using a dynamic simulation methodology that extends the scope of available data with expert judgment. The potential consequences of collisions were modeled in order to determine the requirements for onboard and external emergency response procedures and equipment. The methodology was used to evaluate potential risk reduction measures and to make detailed risk management recommendations to the blue-ribbon panel and the Washington State Transportation Commission.     

A note on the representation of {E\left({\textit{\textbf {x}}}\otimes {\textit{\textbf {xx}}}^{\prime}\right) } and {E\left({\textit{\textbf {xx}}}^{\prime }\otimes {\textit{\textbf {xx}}}^{\prime }\right)} for the random vector x

In this paper we consider ${E(x\otimes xx^{\prime})}$ and ${E(xx^{\prime }\otimes xx^{\prime})}$ for a random vector x where x _i has existing moments up to the fourth order and where the higher moments may depend on i. This extends previous results which assumed a common higher moment and E(xx??)?=?I.     

Order test for high-dimensional two-sample means

We propose a new method to test the order between two high-dimensional mean curves. The new statistic extends the approach of Follmann (1996) to high-dimensional data by adapting the strategy of Bai and Saranadasa (1996). The proposed procedure is an alternative to the non-negative basis matrix factorization (NBMF) based test of Lee et al. (2008) for the same hypothesis, but it is much easier to implement. We derive the asymptotic mean and variance of the proposed test statistic under the null hypothesis of equal mean curves. Based on theoretical results, we put forward a permutation procedure to approximate the null distribution of the new test statistic. We compare the power of the proposed test with that of the NBMF-based test via simulations. We illustrate the approach by an application to tidal volume traces.