1,721,067 research outputs found
Bayesian spatial analysis of demographic survey data: An application to contraceptive use at first sexual intercourse
No full textIn this paper we analyze the spatial patterns of the risk of unprotected sexual intercourse for Italian women during their initial experience with sexual intercourse. We rely on geo-referenced survey data from the Italian Fertility and Family Survey, and we use a Bayesian approach relying on weakly informative prior distributions. Our analyses are based on a logistic regression model with a multilevel structure. The spatial pattern uses an intrinsic Gaussian conditional autoregressive (CAR) error component. The complexity of such a model is best handled within a Bayesian framework, and statistical inference is carried out using Markov Chain Monte Carlo simulation. In contrast with previous analyses based on multilevel model, our approach avoids the restrictive assumption of independence between area effects. This model allows us to borrow strength from neighbors in order to obtain estimates for areas that may, on their own, have inadequate sample sizes. We show that substantial geographical variation exists within Italy (Southern Italy has higher risks of unprotected first-time sexual intercourse). The findings are robust with respect to the specification of the prior distribution. We argue that spatial analysis can give useful insights on unmet reproductive health needs
Assessing the use of sample selection models in the estimation of fertility postponement effects
No full textSeveral studies have shown that at the individual level there exists a negative relationship between age at first birth and completed fertility. Using twin data in order to control for unobserved heterogeneity as possible source of bias, Kohler et al. (2001) showed the significant presence of such "postponement effect" at the micro level. In this paper, we apply sample selection models, where selection is based on having or not having had a first birth at all, to estimate the impact of postponing first births on subsequent fertility for four European nations, three of which have now lowest-low fertility levels. We use data from a set of comparative surveys (Fertility and Family Surveys), and we apply sample selection models on the logarithm of total fertility and on the progression to the second birth. Our results show that postponement effects are only very slightly affected by sample selection biases, so that sample selection models do not improve significantly the results of standard regression techniques on selected samples. Our results confirm that the postponement effect is higher in countries with lowest-low fertility levels
I grandi numeri dell'istruzione secondaria e terziaria
No full textThis works deals with the “big” changes occurred in the upper secondary (high school) and tertiary education in Italy in the last 20 years. It can be divided into three steps: 1. High school, 2. High school-university transition; 3. University enrollment and careers.
High school. With reference to upper secondary education, the educational attendance and attainment have reached very good results in the last 60 years, as 90% of the young students get nowadays a high school diploma with some differences in favor of the northern-central regions of the country. Moreover, there have been profound changes in the choices relating to the type of high school: a decrease of the students attending the “Liceo classico” (with more females); an increase in the “Liceo Scientifico” (males and females are equal just in the last years) and in the “Istituti Tecnici”, attended mostly by males. These Istituti are more frequent in the North of Italy because they are linked to the labour market.
High school-university transition. In the last 60 years, the transition rates from school to university is up and down with a peak in the 90s and in the last years rates are around 50-60%. On the other hand, the number of university students has steadily increased in the 70s and 80s, as the baby boomers were more numerous and more educated than their previous generations. In the last years, there rates have not increased probably due to the economic crisis.
University enrollment and careers. In the 1989/90 female freshmen overcome male freshmen and the distance between females-males have increased in the last 10 years (the total number of freshmen is around 280,000 in the last 10 years).
Performance is better for females students in the Bachelor’s degree courses and it enlarges the differences between males: 27.6 females out of 100 drop out in the 5 years of observation (cohort of freshmen of 2014/15), compared to 37.3 out of 100 males, denoting as males have a greater propensity to leave. On the other hand, observing the transition to the Master, we have noticed - unexpectedly - an inversion, in fact, female students enrolled in the Master within 4 years are 57% (32.6% / (32.6% + 24.6%)) while males enrolled are the 66.5% (29.6% / (29.6% + 14.9%)). This change (keeping in mind that in the master courses females are still 20,000 more numerous than males) is particularly interesting and certainly deserves further studies. Moreover, the school of medicine is very interesting too because females have surpassed males in the number of freshmen in the last 8 years with a similar performance between the two groups. Other “very Italian” issues are considered, as there are still a lot of differences between North and South of Italy, between students coming from “Liceo Classico/scientifico” and students coming from other type of schools, between success in the scientific field and other fields
Home-ownership regimes and lowest-low fertility
No full textWorkshop 2. Session A. Abstract. We investigate to what extent there is an association between the level of fertility and the organization of home-ownership in western countries. We distinguish four home-ownership regimes, based on the share of owner-occupied housing and access to mortgages. We argue that one home-ownership regime is particularly associated with problematic housing-market entry and, therefore, unfriendly to family formation: the \u91difficult\u92 regime combining a high share of owner-occupation and low access to mortgages. We find that lowest-low fertility is mainly found in countries with this particular home-ownership regim
Diffusion processes in demographic transitions: a prospect on using multi agent simulation to explore the role of cognitive strategies and social interactions
No full textDiffusion processes in demographic transitions: a prospect on using multi agent simulation to explore the role of cognitive strategies and social interactions
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Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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