Alessandro Rosina

Mixture modelling of recurrent event times with long-term survivors: Analysis of Hutterite birth intervals

We propose a mixture model that combines a discrete-time survival model for analyzing the correlated times between recurrent events, e.g. births, with a logistic regression model for the probability of never experiencing the event of interest, i.e., being a long-term survivor. The proposed survival model incorporates both observed and unobserved heterogeneity in the probability of experiencing the event of interest. We use Gibbs sampling for the fitting of such mixture models, which leads to a computationally intensive solution to the problem of fitting survival models for multiple event time data with long-term survivors. We illustrate our Bayesian approach through an analysis of Hutterite birth histories.

Young Italian NEETs (Not in Employment, Education, or Training) and the Influence of Their Family Background.

This work investigates the relationship between family variables (parents’ educational level, relationship quality, intrusiveness, support, and autonomy) and young Italians’ status as NEETs (Not in Employment, Education, or Training). We used data from a representative sample of 9,087 young Italians. Each participant filled out an anonymous online questionnaire that contained several scales to measure the variables mentioned above. The results reveal that parents’ educational level and support have a protective effect on the risk of becoming a NEET for both genders. Autonomy has a specific negative impact for males while intrusiveness has a positive impact mainly for females.

Age effect : results from a detailed prospective study on daily fecundability

BACKGROUND Demographers, epidemiologists and clinicians have long been interested in the estimation of age-specific fecundability. With the progressive postponement of age at family formation in Western countries, this topic has recently become the focus of renewed attention. METHODS In order to correctly estimate the effect of biological ageing on fecundability it is crucial to collect detailed information through a rigorous study design and to apply suitable models for analysing time to pregnancy data. In this article we discuss some methodological problems concerning the study of fecundability and its dependence on biological ageing. We also present the Multinational Study in Daily Fecundability which has produced a very rich database with detailed behavioural and physiological information prospectively collected on every cycle. Finally, we review some results on age effects obtained from these data. RESULTS Our findings show that the decline in fecundability from age 28 to age 33 is not statistically significant and very modest. CONCLUSION The results presented here do not appear to be particularly alarming with regard to the postponement of conception of the first child from age 28 to 33. This postponement could however lead to attempts to conceive a second child after age 35, when fecundability starts to decrease rapidly and when the risk of genetic disorders increases.

Where, in which way and to what extent can Italian fertility grow in the next 15 years?

Objective: The study aims at analysing the recent trends in fertility in Italy and at discussing its possible future trends. Methods: We analyse the evolution of demographic indicators, such as the total fertility rate and the maternal age in Italy, in the last 30 years and we look for the most relevant determinants of birth postponement. We also discuss the most recent fertility forecasts for Italy and their implications. Results: In Italy, the total fertility rate has declined sharply in the last 30 years, reaching a level among the lowest in the world. However, in the last decade a reversal in this trend has been recorded. We here show that, net of the effect of immigration, this reversal is mainly due to a recovery of postponed births after age 30. Nevertheless, this recovery is not sufficient to raise the total fertility rates up to the replacement level. The reasons for this insufficient recovery are related both to the marked delay in transition to adulthood and to the difficult reconciliation of work and maternity for Italian women, both hampering the fertility rates. Conclusions: The fertility decline in Italy has finally stopped in the last years even if the maternal age is continuously increasing. However, without ad hoc family policies the fertility recovery will be weak and limited to those areas of the country with a better welfare system and economically more developed.

A model with long-term survivors for the analysis of current-status nuptiality data

The model proposed in this paper combines a logistic regression model and a Weibull regression model for the analysis of current-status data. This joint model allows a simultaneous estimation of two sets of effects on the covariates: one on the probability that the event occurs (also known as quantum) and the other on the timing of the event. Thus, the model can be seen either as an extension of a survival-analysis model for use with current-status data where a survival fraction is added in order explicitly to take into account the possibility that the event may never occur, or as an extension of survival analysis with long-term survivors to the analysis of current-status data. As an illustrative application we apply our model to a study of nuptiality in seventeenth-century Italy.

Using Information on the Age Distribution of Deaths in Population Reconstruction: An Extension of Inverse Projection with Applications

The inverse projection technique, developed by Ronald Lee in the late 1960s, is a well-known method used for “inferring levels and changes in fertility, mortality and population age distributions from observed series of births and deaths, along with some information about population size” [5]. It is a simple and flexible method to use. Over time, some extensions to the technique have been proposed to overcome the assumption of migration absence [4] and for the differentiation of population reconstruction by sex [1]. A further extension has been suggested by Rosina and Rossi [6, 9]. It takes into account some information about the age at death, which is usually available in Italian historical sources. The authors named this modified version of Lee’s algorithm Differentiated Inverse Projection (IPD).

Condizione lavorativa e mobilità internazionale delle nuove generazioni italiane

Durante gli ultimi decenni la struttura sociale ed economica delle societa occidentali ha sperimentato profondi e radicali cambiamenti. Quelli che fra tutti hanno pagato di piu per il contesto economico avverso sono stati i giovani. Il problema di una lunga attesa per la prima occupazione e gli alti tassi di disoccupazione ha interessato le scienze sociali ad analizzare la condizione economica degli under 30 e le strategie che questi hanno messo in atto per affrontare la difficile situazione. Questo contributo aspira ad indagare alcune delle problematiche riguardanti le difficolta dei giovani nel raggiungere la propria indipendenza economica, focalizzandoci specialmente sulle dinamiche e sulle strategie di mobilita interregionale e internazionale alla ricerca di migliori condizioni lavorative e di vita.

The Vulnerability of Young Adults on Leaving the Parental Home

Transitional phases are always those in which people are most at risk, defenceless and vulnerable to external dangers. One of the most crucial changes in human life is the transition to adulthood. Although the timing of such transition has changed, and although the ancient rites of passage have disappeared, crucial stages still persist in the process of acquiring adult autonomy and responsibilities. One of them is leaving the parental home to live on one’s own or to form one’s own family.

Non solo emigrazioni: strategie di risposta alla crisi di fine ’800 nel Veneto

Non solo emigrazioni: strategie di risposta alla crisi di fine ’800 nel Veneto Almeno sino agli anni ‘80 dell’Ottocento il Veneto presentava ancora aspetti tipici di ancien regime. Il fenomeno delle emigrazioni di massa scoppio quasi all’improvviso a sconvolgere una societa definita dagli storici economicamente arretrata, ostile ai cambiamenti, legata a consuetudini ataviche, avvolta in un sistema stratificato di autodifese psicologiche dai rischi che potevano derivare dall’esterno. L’emigrazione fu la risposta piu eclatante, ma non l’unica, adottata per rispondere allo squilibrio tra popolazione e risorse, accentuato dalla crisi agraria di fine Ottocento. Il lavoro proposto evidenzia come in alcuni distretti del Veneto l’emigrazione fu infatti del tutto trascurabile e la risposta alla crisi si attuo attraverso il ricorso a forme flessibili di integrazione del reddito. Inoltre l’emigrazione forni solo una risposta provvisoria ad una crisi che aveva cause strutturali e nuove, rispetto alle crisi di ancien regime, e richiedeva quindi nuove soluzioni, quali l’avvio di un coerente processo di modernizzazione e l’inizio della transizione riproduttiva. In particolare ci si chiede se possa essere individuata una relazione tra crisi di fine Ottocento, emigrazioni di massa ed inizio del declino della fecondita. Not only out-migration: response strategies to the turn of the XIXth century crisis in the Venetian region Until the 1890s, the Veneto region had the typical characteristics of all traditional economies of the ancien regime. The mass emigration, almost suddenly, broke out in an economically backward society. Indeed, the Venetian society was reluctant to all innovations, characterised by ancestral customs, provided with a stratified self-defence system against any external risks. To face the imbalance between population and resources, accentuated by the agricultural crisis of the late XIXth century, the emigration was the most striking solution, even though not the only one. This article shows how in some districts of the Veneto region the emigration was absolutely marginal and how the agrarian crisis was faced by means of flexible systems of income integration. Furthermore, where adopted, the emigration provided only a temporary answer to the crisis. The crisis, brought about by new structural factors, claimed new and more radical solutions, such as: the outset of a coherent modernisation process and the start of the reproduction transition. In particular, we wonder whether the crisis of the late XIXth century, the mass emigration and the start of the fertility decline may be existed.

The dejuvenation of the Italian population

Abstract In recent decades, a process of structural reduction of the weight of new generations in overall population (dejuvenation) has been observed. In Italy, this process started in the 1970s and accelerated in the 1990s. We present here its main consequences for Italian society and economy. The number of Italian young people (aged 0–29) was reduced from 24.5 million in 1951 (51.6% of the population) to 17.5 million in 2016 (28.8%). What is more, many young Italians are becoming a wasted resource and a social cost, facing high rates of unemployment, long economic dependence on the family of origin, renunciation of full achievement of their life plans, distrust of institutions, low social and political participation, and increasing emigration flow. We analyze, using multivariate models, the data of the Rapporto Giovani survey held by the Toniolo Institute in 2015. Our main finding is that generational disadvantages not only hamper economic growth but, in a familistic context, also exacerbate social inequalities.