Nonlinear mixed-effects models with scale mixture of skew-normal distributions

Aiming to avoid the sensitivity in the parameters estimation due to atypical observations or skewness, we develop asymmetric nonlinear regression models with mixed-effects, which provide alternatives to the use of normal distribution and other symmetric distributions. Nonlinear models with mixed-effects are explored in several areas of knowledge, especially when data are correlated, such as longitudinal data, repeated measures and multilevel data, in particular, for their flexibility in dealing with measures of areas such as economics and pharmacokinetics. The random components of the present model are assumed to follow distributions that belong to scale mixtures of skew-normal (SMSN) distribution family, that encompasses distributions with light and heavy tails, such as skew-normal, skew-Student-t, skew-contaminated normal and skew-slash, as well as symmetrical versions of these distributions. For the parameters estimation we obtain a numerical solution via the EM algorithm and its extensions, and the Newton-Raphson algorithm. An application with pharmacokinetic data shows the superiority of the proposed models, for which the skew-contaminated normal distribution has shown to be the most adequate distribution. A brief simulation study points to good properties of the parameter vector estimators obtained by the maximum likelihood method.     

Oxytocin discontinuation after the active phase of induced labor: A systematic review

Background

Oxytocin is the most widely used drug in the induction of labor, but it could have potential adverse effects that derive from uterine hyperstimulation.

Evaluating the Quality of Urban Development Plans Promoted by the European Union: The URBAN and URBANA Initiatives in Spain (1994–2013)

Since the 1990s, the European Union has launched different programs to promote urban development plans. Implementation and outcomes evaluations have resulted in a “European urban acquis” concerning the importance of comprehensiveness, collaborative governance, and participation to promote “good plans.” However, the evaluation of the quality of local plans, has received less attention. This article analyses quality of local plans developed under the framework of European Policies in Spain applying the plan quality evaluation approach, as well as factors explaining quality levels of these local plans. A scale to measure plan quality is proposed based on five main dimensions (fact base, objectives, policy actions, plan governance, evaluation). 64 local plans are analyzed applying content analysis. RgW and AD tests are used to measure codification reliability. Confirmatory factor analysis (CFA) is used to assess the validity of plan quality scale. Lineal regression is applied to analyze the impact of different aspects of planning process included in the ‘European urban acquis’ on plan quality. Main results show that CFA validates the scale proposed to measure local plan quality as a second-order factor; and point out objectives and policy actions as the most important first-order factors. Public participation during planning process, and more comprehensive plan across different policy areas, are the main factors explaining ‘good plans’. Therefore, the importance of the ‘European urban acquis,’ is confirmed in order to produce ‘good’ urban development plans; and the article provides a validated scale to evaluate the quality of urban development plans, and their main dimensions.

     

Latent class models for ecological inference on voters transitions

This paper introduces some new models of ecological inference within the context of estimation of voter transitions across elections. In particular, we assume that voters of a given party in a given occasion may be split into two latent types: faithful voters, who will certainly vote again for the same party and movers, who will reconsider their choice. Our models allow for unobserved heterogeneity across polling stations both in the weights of the two latent classes within each party and also when modelling the choice of unfaithful voters. Different ways of modelling the unobserved heterogeneity are considered by exploiting properties of the Dirichlet-multinomial distribution and the Brown Payne model of voting transitions can be seen as a special case within the class of models presented here. We discuss pseudo-maximum likelihood estimation and present an application to recent elections in Italy.     

Anthropogenic noise and atmospheric absorption of sound induce amplitude shifts in the songs of Southern House Wren (Troglodytes aedon musculus)

Urban Ecosystems - Birdsong is an important feature that mediates several aspects of bird reproduction, such as mate choice, territory defense, and individual recognition. Any factor that impairs...     

Legal indigeneity: knowledge,legal discourse and the construction of indigenous identity in Colombia

ABSTRACT

This paper analyses the creation of the indigenous legal subject in Colombia from the perspective of legal-knowledge regimens. It analyses the turn from medical psychiatric assessments to indigenous identity to anthropological discourses on cultural differences. This article describes the legal construction of the indigenous subject in two historical moments. On the one hand, in the context of formation of the nation-state in Colombia and, on the other hand, in the transition towards contemporary multicultural constitutionalism within which legal discourse creates taxonomies for the definition of identities and the recognition of special rights to people who claim to be indigenous.     

Bayesian estimation of a flexible bifactor generalized partial credit model to survey data

Item response theory (IRT) models provide an important contribution in the analysis of polytomous items, such as Likert scale items in survey data. We propose a bifactor generalized partial credit model (bifac-GPC model) with flexible link functions - probit, logit and complementary log-log - for use in analysis of ordered polytomous item scale data. In order to estimate the parameters of the proposed model, we use a Bayesian approach through the NUTS algorithm and show the advantages of implementing IRT models through the Stan language. We present an application to marketing scale data. Specifically, we apply the model to a dataset of non-users of a mobile banking service in order to highlight the advantages of this model. The results show important managerial implications resulting from consumer perceptions. We provide a discussion of the methodology for this type of data and extensions. Codes are available for practitioners and researchers to replicate the application.     

New MNE subsidiaries in old clusters: when,why, and how

Despite the rise of globalization, industrial clusters remain vibrant spaces for the generation of knowledge and innovation. Aware of this reality, multinational enterprises (MNEs) seek to reconcile the advantages of international operations with the specific endowments of individual territories. By studying the case of the Inditex subsidiary in the Vinalopó footwear cluster, this research shows how the creation and activity of a specialized subsidiary and the evolution of the industrial system interweave. The study shows that, rather than agglomeration per se, access to specific resources guides location as the cluster matures. Furthermore, local embeddedness shapes post-entry dynamics at the micro and meso levels. Autonomous decisions boost the subsidiary’s access to local networks and the exploitation of cluster advantages, aiding the resilience of the cluster by contributing extra-cluster knowledge.     

The joy of ruling: an experimental investigation on collective giving

We analyse team dictator games with different voting mechanisms in the laboratory. Individuals vote to select a donation for all group members. Standard Bayesian analysis makes the same prediction for all three mechanisms: participants should cast the same vote regardless of the voting mechanism used to determine the common donation level. Our experimental results show that subjects fail to choose the same vote. We show that their behaviour is consistent with a joy of ruling: individuals get an extra utility when they determine the voting outcome.