Working papers results

The study of network representations of physical, biological, and social phenomena has developed rapidly in recent years. This paper presents a review of important results and methods of the science of networks with an application to the field of socio-economic systems. The basic definitions and computational techniques are described and the effects of a networks topology on its dynamic properties are examined and illustrated using a tourism destination as a case study (Elba, Italy). A static structural characterization of the network formed by destination stakeholders is followed by a dynamic analysis of the information diffusion process. The outcomes and the implications of this analysis for improving destination management are discussed.

Propensity Score Matching (PSM) has become a popular approach to estimation of causal effects. It relies on the assumption that selection into a treatment can be explained purely in terms of observable characteristics (the unconfoundedness assumption) and on the property that balancing on the propensity score is equivalent to balancing on the observed covariates. Several applications in social sciences are characterized by a hierarchical structure of data: units at the first level (e.g., individuals) clustered into groups (e.g., provinces). In this paper we explore the use of multilevel models for the estimation of the propensity score for such hierarchical data when one or more relevant cluster-level variables is unobserved. We compare this approach with alternative ones, like a single level model with cluster dummies. By using Monte Carlo evidence we show that multilevel specifications usually achieve reasonably good balancing in cluster level unobserved covariates and consequently reduce the omitted variable bias. This is also the case for the dummy model.

More educated parents are observed to have better educated children. Researchers trying to control for unobserved ability have found conflicting results: in most cases, they have found a strong positive paternal effect but a negligible maternal effect. In this paper, I use a population of twins from Norwegian Register data and evaluate the impact on the robustness of the estimates of the characteristics of the samples commonly used in this strand of research: samples of small size, with low variability in parental education, not randomly selected from the population. The part of the educational distribution involved in any identification strategy seems to be the key aspect to take into account to reconcile previous results from the literature.

Using age specific fertility rates of Italian and Swedish women aged between 15 and 49 years old I examine the presence of fertility postponement in period and cohort outputs. Period data consist of standard five-year age group rates ranging from 1960 to 2005. Cohort data are arranged on age specific year groups born between years 1930-1970. The method used in this work is based upon quadratic spline interpolation procedure, developed by Carl P. Schmertmann (2003), in which three index ages determine the schedules shape. The recent fertility postponing behavior is investigated through the help of five index ages, which show the dynamics of postponement both in cohort and period data.

Students' experiences at university prepare them for a future in which they are expected to engage in life-long learning. Self-efficacy theory suggests that a persons beliefs in their capacity to learn will influence their participation in learning. This paper describes development of a new scale to measure self-efficacy for learning (SEL) among university students, designed to be appropriate for both campus-based and online learning, and for administration in a battery of tests on student development. Undergraduate students (n = 265) in a business school in Milan and a department of psychology in Rome participated in the final study. Beginning with a random sample of 200 participants, item response theory and exploratory factor analysis with LISREL were used to identify a 10 item scale to measure SEL. The scales properties were confirmed in a second random sample of 200 participants, using confirmatory factor analysis in LISREL. Correlation with expected grades was, consistent with earlier studies, moderately small (.22), but statistically significant.

The discussion on the causes of the most recent fertility decline in Europe, and in particular on the emergence of lowest low fertility, emphasizes the relevance of cultural factors as compared to economic ones. Within such framework, the heterogeneity of preferences concerning the career vs. family dichotomy has been systematized in the Preference Theory approach developed by Catherine Hakim. This heterogeneity, however, has been so far underinvestigated in a comparative framework. This paper makes use of new comparative data from the 2004/05 Round of the European Social Survey to test the links between individual-level preferences and both fertility outcomes and fertility intentions, in a variety of societal settings. Results confirm an association between work-family lifestyle preferences and realized fertility in a variety of European countries, while they do not support the relevance of lifestyle preferences on fertility intentions.