On sufficient conditions for the strong consistency of least-squares estimates

The strong consistency of the least-squares estimates in regression models is obtained when the errors are i.i.d. with absolute moment of order r, 0<r? 2. The assumptions presented for the random error sequence will permit us to obtain improvements of the conditions on the regressors in order to obtain the strong consistency of the least-squares estimates in linear and nonlinear regression models.     

Random translation of discrete order statistics

We investigate the existence and uniqueness of a discrete parent distribution supported on the integers whose order statistics are related by a random translation. We also provide some examples using the constructive method that we propose.     

Strong consistency of least squares estimates with i.i.d. errors with mean values not necessarily defined

We establish strong consistency of the least squares estimates in multiple regression models discarding the usual assumption of the errors having null mean value. Thus, we required them to be i.i.d. with absolute moment of order r, 0<r<2, and null mean value when r>1. Only moderately restrictive conditions are imposed on the model matrix. In our treatment, we use an extension of the Marcinkiewicz–Zygmund strong law to overcome the errors mean value not being defined. In this way, we get a unified treatment for the case of i.i.d. errors extending the results of some previous papers.     

Lower posterior death probabilities from a quick medical response in road traffic accidents

Introduction: We use data from Spain on roads and motorways traffic accidents in May 2004 to quantify the statistical association between quick medical response time and mortality rate. Method: Probit and logit parameters are estimated by a Bayesian method in which samples from the posterior densities are obtained through an MCMC simulation scheme. We provide posterior credible intervals and posterior partial effects of a quick medical response at several time levels over which we express our prior beliefs. Results: A reduction of 5 min, from a 25-min response-time level, is associated with lower posterior probabilities of death in roads and motorways accidents of 24% and 30%, respectively.     

Decolonising the university in 2020

ABSTRACT

We came together as editors of Decolonising the University through a commitment to understanding the university and our place within it; to examine what else might be possible for us, collectively, in the domain of higher education. Although we do not always agree about the university– or, perhaps more specifically, about the possibilities it contains for intervening effectively in the world– we nonetheless coalesced around an idea of ‘decolonising the university’ as an important strategic mode of engagement. Here, we set out the positions that we come from in relation to the broader debates about the university and its political possibilities and offer responses also to the reviews. These are not our final words on the matter, but words shaped by the political possibilities that present themselves at the outset of 2020 and which, we hope, will contribute to the increasingly necessary dialogues on this topic.     

Female executives and the glass ceiling in Spain

This paper examines the findings of a survey of the personal, educational and professional profiles of a sample of male and female senior executives of companies operating in Spain. The women were found to be younger; they had fewer children, resorted to more domestic help, and earned less than the men, although they often had higher qualifications. Yet cultural patterns and institutional barriers still prevent them from making full use of their capabilities. In spite of recent legislative efforts to promote gender equity at work, more than nine out of ten senior executives are still men.     

Profiles identification on hierarchical tree structure data sets

In this work we study a way to explore and extract more information from data sets with a hierarchical tree structure. We propose that any statistical study on this type of data should be made by group, after clustering. In this sense, the most adequate approach is to use the Mahalanobis–Wasserstein distance as a measure of similarity between the cases, to carry out clustering or unsupervised classification. This methodology allows for the clustering of cases, as well as the identification of their profiles, based on the distribution of all the variables that characterises each subject associated with each case. An application to a set of teenagers' interviews regarding their habits of communication is described. The interviewees answered several questions about the kind of contacts they had on their phone, Facebook, email or messenger as well as the frequency of communication between them. The results indicate that the methodology is adequate to cluster this kind of data sets, since it allows us to identify and characterise different profiles from the data. We compare the results obtained with this methodology with the ones obtained using the entire database, and we conclude that they may lead to different findings.     

Time as a limited resource: Communication strategy in mobile phone networks

We used a large database of 9 billion calls from 20 million mobile users to examine the relationships between aggregated time spent on the phone, personal network size, tie strength and the way in which users distributed their limited time across their network (disparity). Compared to those with smaller networks, those with large networks did not devote proportionally more time to communication and had on average weaker ties (as measured by time spent communicating). Further, there were not substantially different levels of disparity between individuals, in that mobile users tend to distribute their time very unevenly across their network, with a large proportion of calls going to a small number of individuals. Together, these results suggest that there are time constraints which limit tie strength in large personal networks, and that even high levels of mobile communication do not fundamentally alter the disparity of time allocation across networks.     

A social policy model for the reconciliation of employment and family life from a gender equality perspective

The issue of family–employment reconciliation has rapidly evolved from being ignored to a certain dejá vu perception in public debate, as a result of its media success during the last decade. This is even more the case in Spain, where it was only in the late 1990s, when a law was passed to regulate and extend parental and other leave for workers with close relatives in need of care, that reconciliation policies began to be generally discussed and considered. In a context of quick population aging as a consequence of low fertility, concern on labor force supply in the middle term is high on the agenda. Women are increasingly considered to be necessary both as workers and mothers (of future workers), thus raising awareness of the importance of social policies to make their double presence in both worlds possible. There is now general agreement from the right to the left on the urgency to develop family–employment policies. But what is not generally addressed is the impact of such policies on gender equality, a dimension which tends to be either ignored or taken for granted. Not all reconciliation measures have the same effects on the women and men relationship. Some of them push forward equality, whereas others go backwards. Efficiency in making job and family responsibilities compatible does not always go hand in hand with increasing equality. The paper presents a theoretical model for the reconciliation of work and family life from a gender equality perspective. The three main kinds of instruments available in social policy – services, leave, and cash – are examined in four different cases: care of under-threes, care of sick children, coordination of work and school schedules, and care of children during school holidays. Each case is looked at considering its effects on social and gender equality, as well as child welfare. The model includes as active agents of the system the State (promotes and regulates), families and individuals (those directly implicated), and the market as labor market, on the one hand, and supplier of private services, on the other.