Analysis of individual- and time-specific covariate effects on survival of Serinus serinus in north-eastern Spain

We developed models for the analysis of recapture data for 2678 serins ( Serinus serinus ) ringed in north-eastern Spain since 1985. We investigated several time- and individual-specific factors as potential predictors of overall mortality and dispersal patterns, and of gender and age differences in these patterns. Time-specific covariates included minimum daily temperature, days below freezing, and abundance of a strong competitor, siskins ( Carduelis spinus ) during winter, and maximum temperature and rainfall during summer. Individual covariates included body mass (i.e. body condition), and wing length (i.e. flying ability), and interactions between body mass and environmental factors. We found little support of a predictive relationship between environmental factors and survival, but good evidence of relationships between body mass and survival, especially for juveniles. Juvenile survival appears to vary in a curvilinear manner with increasing mass, suggesting that there may exist an optimal mass beyond which increases are detrimental. The mass-survival relationship does seem to be influenced by at least one environmental factor, namely the abundance of wintering siskins. When siskins are abundant, increases in body mass appear to relate strongly to increasing survival. When siskin numbers are average or low the relationship is largely reversed, suggesting that the presence of strong competition mitigates the otherwise largely negative aspects of greater body mass. Wing length in juveniles also appears to be related positively to survival, perhaps largely due to the influence of a few unusually large juveniles with adult-like survival. Further work is needed to test these relationships, ideally under experimentation.     

Analysis of individual- and time-specific covariate effects on survival of Serinus serinus in north-eastern Spain

We developed models for the analysis of recapture data for 2678 serins ( Serinus serinus ) ringed in north-eastern Spain since 1985. We investigated several time- and individual-specific factors as potential predictors of overall mortality and dispersal patterns, and of gender and age differences in these patterns. Time-specific covariates included minimum daily temperature, days below freezing, and abundance of a strong competitor, siskins ( Carduelis spinus ) during winter, and maximum temperature and rainfall during summer. Individual covariates included body mass (i.e. body condition), and wing length (i.e. flying ability), and interactions between body mass and environmental factors. We found little support of a predictive relationship between environmental factors and survival, but good evidence of relationships between body mass and survival, especially for juveniles. Juvenile survival appears to vary in a curvilinear manner with increasing mass, suggesting that there may exist an optimal mass beyond which increases are detrimental. The mass-survival relationship does seem to be influenced by at least one environmental factor, namely the abundance of wintering siskins. When siskins are abundant, increases in body mass appear to relate strongly to increasing survival. When siskin numbers are average or low the relationship is largely reversed, suggesting that the presence of strong competition mitigates the otherwise largely negative aspects of greater body mass. Wing length in juveniles also appears to be related positively to survival, perhaps largely due to the influence of a few unusually large juveniles with adult-like survival. Further work is needed to test these relationships, ideally under experimentation.     

The effects of wage flexibility on activity and employment in Spain

In this paper we estimate the macroeconomic effects of the greater wage and firms’ internal flexibility promoted by the economic policies implemented since 2012, which changed markedly Spanish labour regulations. To do so, we propose a structural VAR that allows us to break down changes in main macroeconomic variables into different structural shocks. From a policy perspective, the estimation of the structural shocks allows us to simulate a counterfactual scenario, whereby we conclude that the effects of less rigid labour market are positive and significant. Our results suggest that, if these policies were implemented at the beginning of the crisis, they could have avoided a significant part of the falls in GDP and employment.     

Reflections on gains and losses: A 2 × 2 × 7 experiment

What determines risk attraction or aversion? We experimentally examine three factors: the gain-loss dichotomy, the probabilities (0.2 vs. 0.8), and the money at risk (7 amounts). We find that the majority display risk attraction for small amounts of money, and risk aversion for larger amounts. Yet the frequency of risk attraction varies according to the gain-loss dichotomy and the probabilities. Kahneman and Tversky studied gain-loss reflections. We submit that a reflection can be decomposed into a translation and a probability switch. We find significant translation and switch effects, which are of comparable magnitude, a result that is equidistant from the diverging two popular views inspired by Prospect Theory: the gain-loss asymmetry, and the fourfold pattern.     

Convergence in the OECD: Transitional Dynamics or Narrowing Steady-State Differences?

In this article we show that the picture emerging from models that allow for generalized parameter heterogeneity in convergence equations changes our view of the convergence process within the OECD. Estimation methods that allow for non- or partial heterogeneity stress the importance of transitional dynamics. Thus the observed reduction in the dispersion of per capita income is mostly explained by transitional dynamics. When generalized parameter heterogeneity is allowed for, we find that the observed narrowing of incomes has little bearing on transitional dynamics. Convergence in this case happens because the long-run features of these countries are becoming increasingly similar.     

Design optimisation for pharmacokinetic modeling of a cocktail of phenotyping drugs

Our paper proposes a methodological strategy to select optimal sampling designs for phenotyping studies including a cocktail of drugs. A cocktail approach is of high interest to determine the simultaneous activity of enzymes responsible for drug metabolism and pharmacokinetics, therefore useful in anticipating drug–drug interactions and in personalized medicine. Phenotyping indexes, which are area under the concentration‐time curves, can be derived from a few samples using nonlinear mixed effect models and maximum a posteriori estimation. Because of clinical constraints in phenotyping studies, the number of samples that can be collected in individuals is limited and the sampling times must be as flexible as possible. Therefore to optimize joint design for several drugs (i.e., to determine a compromise between informative times that best characterize each drug's kinetics), we proposed to use a compound optimality criterion based on the expected population Fisher information matrix in nonlinear mixed effect models. This criterion allows weighting different models, which might be useful to take into account the importance accorded to each target in a phenotyping test. We also computed windows around the optimal times based on recursive random sampling and Monte‐Carlo simulation while maintaining a reasonable level of efficiency for parameter estimation. We illustrated this strategy for two drugs often included in phenotyping cocktails, midazolam (probe for CYP3A) and digoxin (P‐glycoprotein), based on the data of a previous study, and were able to find a sparse and flexible design. The obtained design was evaluated by clinical trial simulations and shown to be efficient for the estimation of population and individual parameters. Copyright © 2015 John Wiley & Sons, Ltd.     

Parental employment and time with children in Spain

This paper studies whether the allocation of childcare time differs across gender, parental employment and other characteristics in Spain. Results show that mothers provide substantially more care for Essential Needs Activities and Secondary Childcare than fathers, but the care for Educational Activities is similar. The analysis also shows that fathers and mothers in employment spend more time on Educational Activities than their counterparts who are not working, and that parental education generally increases childcare for Essential Needs and Educational Activities. Finally, the study suggests that ending the working day no later than 6 p.m. would significantly raise the time allocated to childcare by working parents.     

The impact of the labour market on the timing of marriage and births in Spain

This paper investigates how education and the labour market affect Spanish individual decisions on the timing of marriage and births, using a Cox hazard approach. It disentangles men and women, and two groups, Cohort 1945–1960 and Cohort 1961–1977. Results show that female employment delays marriage in Cohort 1945–1960, but it has a reverse effect in Cohort 1961–1977. We also find evidence that employment is a barrier for family formation since employed women postpone births in both cohorts. The precarious Spanish labour markets, captured by female unemployment rates, delay family formation, especially by putting off marriage. Male unemployment, at the individual level, impacts negatively on fertility only through delaying marriage.

Employment Transitions after Motherhood in Spain

Abstract. This paper investigates transitions from employment to non‐employment and downward occupational mobility after motherhood in Spain. Around 40 per cent of Spanish women who were at work 1 year before childbearing leave employment, most permanently, and one‐third of these exits move to unemployment. The probability of staying on at work after birth is reduced with the rise of fixed‐term contracts and increased with experience and level of education. Downward occupational mobility is not common amongst women remaining employed since they do not switch to part‐time jobs.