Mixture inverse Gaussian for unobserved heterogeneity in the autoregressive conditional duration model

In this paper, we assume that the duration of a process has two different intrinsic components or phases which are independent. The first is the time it takes for a trade to be initiated in the market (for example, the time during which agents obtain knowledge about the market in which they are operating and accumulate information, which is coherent with Brownian motion) and the second is the subsequent time required for the trade to develop into a complete duration. Of course, if the first time is zero then the trade is initiated immediately and no initial knowledge is required. If we assume a specific compound Bernoulli distribution for the first time and an inverse Gaussian distribution for the second, the resulting convolution model has a mixture of an inverse Gaussian distribution with its reciprocal, which allows us to specify and test the unobserved heterogeneity in the autoregressive conditional duration (ACD) model.

Our proposals make it possible not only to capture various density shapes of the durations but also easily to accommodate the behaviour of the tail of the distribution and the non monotonic hazard function. The proposed model is easy to fit and characterizes the behaviour of the conditional durations reasonably well in terms of statistical criteria based on point and density forecasts.     

The gender gap in pensions in Latin America

Lower female lifetime labour market participation rates, greater interruptions during their working lives, and wage gaps contribute to create gender gaps in pensions at the time of retirement. The design of social security systems may reinforce or attenuate these gaps. This article provides new evidence on gender gaps in access to pensions and in pension income in four Southern Cone countries in Latin America and analyses their evolution between 2000 and 2013, showing significant improvements in both gaps, with differential patterns by countries. The decrease in the gender gap in pension income has been particularly significant in Argentina and Brazil. In both cases, the largest increases in pension values during the period correspond to the lowest income percentiles, where women are overrepresented. The application of redistributive policies in these countries, aimed at reducing poverty and inequality but not necessarily focused on gender equity, has had positive and probably unintended consequences in terms of reduction in gender gaps in pensions.     

Contact between birth parents and children in kinship care in a sample from Spain

Within the context of kinship care, the main objectives of this work are to study the characteristics of contact between foster children and their birth parents, and their relationship with key variables of fostering, the children and their kinship caregivers. The sample included 189 children from Spain and their kinship families. A semi‐structured placement interview and two scales relating to the child–caregiver relationship and child's psychological adjustment were used with the kinship families. The results revealed a significant percentage of foster children who had no family contact. Various visit types, frequencies and durations were described. Kinship care with contact, compared with placements without contact, was frequently characterized by the absence of professional supervision, and an affectionate child–caregiver relationship; moreover, children with contact were perceived to have fewer serious behaviour and socio‐emotional problems and a greater probability of family reunification. The regression analysis showed that the main predictors for how caregivers assessed contact were the children's emotional reaction during visits and the quality of the relationship between the kinship families and the birth parents. These results suggest the need for further research about contact, which will certainly have a major impact on professional intervention with these families.     

Promoting healthy transition to college through mindfulness training with first-year college students: Pilot randomized controlled trial

Objective: Given the importance of developmental transitions on young adults' lives and the high rates of mental health issues among U.S. college students, first-year college students can be particularly vulnerable to stress and adversity. This pilot study evaluated the effectiveness and feasibility of mindfulness training aiming to promote first-year college students' health and wellbeing. Participants: 109 freshmen were recruited from residential halls (50% Caucasian, 66% female). Data collection was completed in November 2014. Methods: A randomized control trial was conducted utilizing the Learning to BREATHE (L2B) program, a universal mindfulness program adapted to match the developmental tasks of college transition. Results: Participation in the pilot intervention was associated with significant increase in students' life satisfaction, and significant decrease in depression and anxiety. Marginally significant decrease was found for sleep issues and alcohol consequences. Conclusions: Mindfulness-based programs may be an effective strategy to enhance a healthy transition into college.     

Individual Pension Plans in Spain: How Expected Change in Future Income and Liquidity Constraints Shape the Behavior of Households

Understanding the motives that underlie Spaniards’ retirement saving decisions is important because many, if not most, future retirees will need to rely on personal savings to maintain a decent standard of living. The governor of the Bank of Spain has stated recently that the current public pension system will not guarantee an adequate pension to the citizens, advising to save now for retirement. In this debate on public pensions, and the complementary role that private pensions might play in Spain, this article has shed light on the decision of Spanish households to engage in individual pension plans and it has identified which factors determine the total amount saved in such retirement plans. Using micro data from the Bank of Spain (Survey of Household Finances 2011), the analysis has revealed that the expectations of lower future income, along with preferences for the financial risk and education, exert an important influence on the likelihood of enrolling in a private pension plan. University education minimizes the myopic behavior of households in the sense of making them more forward-looking and cautious in the face of their future well-being. Additionally using Heckman’s methodology to correct for the problem of selection bias, our results have revealed that liquidity constraints affect negatively the total amount of money saved for retirement.     

Bat boxes in urban non-native forests: a popular practice that should be reconsidered

Impact mitigation practices are currently one of the hottest topics in conservation and regarded as priorities worldwide. Forest bat populations are known to provide important ecosystem services such as pest control and bat boxes have become one of the most popular management options for counteracting the loss of roosts. However, bat boxes tend to be employed in non-native forests near highly humanized areas where human disturbance is higher. The aim of this study was to evaluate how the surrounding landscape composition affects bat box occupancy in urban non-native forests along the Mediterranean corridor in the Northeastern Iberian Peninsula. Two hundred wooden bat boxes were monitored in young non-native forests in the period 2004–2012. The influence of land cover on occupancy rate of bat boxes was analysed at the landscape level in a 5 km buffer around bat-box stations. In total, 1659 inspections were carried out, in which a 15 % occupancy rate was detected. Bat boxes hosted three different species (Pipistrellus pygmaeus, Pipistrellus kuhlii and Nyctalus leisleri). More than 70 % of the occupancy can be explained by habitat and spatial composition. The presence of urban areas around bat boxes tends to have a negative impact on bat occupation rates; by contrast, forest coverage has a positive effect, especially for the tree-dwelling bats. These patterns could be associated with the large number of available roosts in buildings, microhabitat or phylopatry. Thus, to increase success, we suggest that landscape composition should be considered when using bat boxes for conservation.     

Roma and the politics of double discourse in contemporary Europe

ABSTRACT

The article analyses the politics of ‘double discourse’ in relation to Roma that has evolved in contemporary neoliberal Europe. On the one hand, the double discourse promotes the integration, rights and equal opportunities of Roma, on the other, it denies recognition of, and ways to address, enduring structural violence and rising social insecurity. The article argues that the politics of ‘double discourse’, as a neoliberal approach towards Roma, is structured by two contradictory discourses that speak to different audiences, using duplicitous approaches to create anti-Roma consensus and maintain the critical difference and subordinated position of the racialised Romani populations in Europe. By studying the representation of Roma in the cases of so-called 'child theft' in Greece and Ireland, and in the recent ‘refugee crisis’, the paper identifies and discusses three dimensions of contemporary neoliberal double discourse: racialised de-Europeanisation, neoliberal undeservingness and (dis)articulation of citizenship.     

Urban habitats can affect body size and body condition but not immune response in amphibians

Does urbanization affect key life-history traits in native organisms? Some studies show that urban areas reduce diversity in certain taxa, but there is little insight into how these environments affect physiological and ecological traits. Urban areas have distinct physical structure and ecological processes compared to original habitats. The environmental changes associated with urban areas can influence the costs and benefits of different traits and behaviors of local organisms. Some of these effects have been explored in groups such as birds, but we might expect stronger effects in animals with reduced mobility, such as amphibians. Importantly, the effects of urban habitats on amphibians have not been explored, in spite that these are the most threatened vertebrate group in the world. Here, we compared three main traits related to the fitness of amphibians in urban and natural habitats: body size, body condition and immune response. To test the generality of our results, we assessed adult males of four amphibian species. We found that the body size was larger in urban environment populations in three of four studied species, while the body condition was better in the urban populations of two aquatic newt species. Finally, we found no effect of urbanization on the immune response of individuals of any species. In conclusion, we show that different species of amphibians may be affected differently by anthropogenic habitat alteration depending on their specific ecology.     

Digital media,subcultural activity and youth participation: the cases of protest rap and graffiti in Portugal

Over the last decade, we have witnessed the emergence of an academic debate surrounding the relationship between youth and the ‘new media’, with a particular emphasis on the social uses of different digital technologies within the sphere of youth activity. A specific area of research has been dedicated to studying the use of digital media in the context of the so-called youth subcultures. With this article we expect to contribute to this ongoing debate, by examining the problem through an analysis of two interconnected case studies: protest rap and illegal graffiti. Both cases may be defined as subcultures, insofar as they are characterized as alternative, subterranean, and to a certain extent, subversive movements. The empirical ground for this discussion is based on several investigations, with a qualitative basis, carried out by the authors in the course of over a decade in Portugal. This extended time frame allowed ample access to a diversified and matured analytical material and enabled a better perspective of the developments and the mutations involving the appropriation of the digital media. Our researches have shown that digital media and technologies have been gradually integrated in these urban youth subcultures, accomplishing several strategic roles.