Working papers results

Agent-based modelling and numerical simulations are means that facilitate exploring the structural and dynamic characteristics of systems which may prove intractable with analytical methods. This contribution examines the issues related to them with a particular attention to their use in the study of social economic and ecological systems. Besides a general description, the possibilities, limitations and their relationship with other more traditional investigation methods are examined. Special focus is put on the assessment of their validation and reliability. Finally an application example is provided. A simple model is built to analyse the movements of tourists and the relationship between these and the attractiveness of a tourism destination. The results are discussed along with possible future developments.

We use the theory of planned behavior to investigate the role of attitudes, norms and perceived behavioural control on short-term and long-term fertility intentions, using data from Norway (N = 1,307). There is some evidence that, net of other background variables, positive scores on these factors makes it easier to establish concrete childbearing plans, especially among parents. Subjective norms are particularly important among both parents and childless adults, while perceptions of behavioural control have no additional effect once the actual life situation is taken into account. Attitudes are not important in decisions about the timing of becoming a parent, probably because the main issue for childless adults is not the timing, but the decision to have a child or not.

The aim of this paper is to assess the quality of the ranking of institutions obtained with multilevel techniques in presence of different model misspecifications and data structures. Through a Monte Carlo simulation study, we find that it is quite hard to obtain a reliable ranking of the whole effectiveness distribution while, under various experimental conditions, it is possible to identify institutions with extreme performances. Ranking quality increases with increasing intra class correlation coefficient and/or overall sample size. Furthermore, multilevel models where the between and within cluster components of first-level covariates are distinguished perform significantly better than both multilevel models where the two effects are set to be equal and the fixed effect models.

Using a specific data set drawn from the Spanish Module Education to Labour Market Transitions (2000), this paper analyses the labour market entrance of Spanish school leavers and the match between education and work at the early stages of working life. Moreover, special attention is paid to graduates, because Spain experienced a strong growth in the demand for higher education during the last decades of 20th century. The empirical evidence shows that, besides other personal and family individual's characteristics, human capital exerts a strong influence on the finding of an employment. With regard to the match between education and work, the results indicate that over-education is a common phenomenon in the Spanish youth labour market. However, unlike what one could expect, being a graduate seems to be associated to a lower likelihood of over-education in the first employment.

In this paper the question of within-country heterogeneity in patterns of transition to adulthood is addressed, focusing on the exit from the parental home in Spain, a country representative of the latest-late transition to adulthood. Microcensus data are used to investigate the relative weight that structural-contextual factors measured at the municipal level and cultural factors measured at the provincial level might have in explaining regional existing differences in the transition to independent living, by applying multilevel multinomial logistic model on three choices of living arrangements, namely, co-residing with parents, living outside the parental home and in partnership, living outside the parental home and not in partnership.

Surveys differ in the way they measure satisfaction and happiness, so comparative research findings are vulnerable to distortion by survey design differences. We examine this using the British Household Panel Survey, exploiting its changes in question design and parallel use of different interview modes. We find significant biases in econometric results, particularly for gender differences in attitudes to the wage and hours of work. Results suggest that the common empirical finding that women care less than men about their wage and more about their hours may be an artifact of survey design rather than a real behavioural difference.

We present an introduction to the NetLogo simulation environment using the Segregation Model presented by Nobel Prize Winner Thomas Schelling in 1978. While reviewing the model, its Netlogo implementation is described step by step, using visual tools accompanied by the code for programming in the Netlogo language. Two extensions to the original model are proposed and programmed. All the models are fully described in the text.

This paper investigates the role of extended parental leave in the return to work of mothers of newborn children. Exploiting the variability in policies offered by European countries, the paper studies the influence of statutory leave on the probability of returning to work at different ages of the child. Results suggest that providing paid leaves increases the probability of remaining at home when the child is under 3, and that lengthy statutory leaves are associated with being more likely to return eventually to work.

This paper aims to answer to what extent fertility has a causal effect on households economic wellbeing-an issue that has received considerable interest in development studies and policy analysis. However, only recently has the literature begun to give importance to adequate modelling for estimation of causal effects. We discuss several strategies for causal inference, stressing that their validity must be judged on the assumptions we can plausibly formulate in a given application, which in turn depends on the richness of available data. This discussion has a general importance, representing a set of guidelines that can be helpful to choose the appropriate strategy of analysis. We contrast methods relying on the Unconfoundedness Assumption, which include regressions and propensity score matching, with Instrumental Variable methods. We discuss why they give different estimates of the causal effect using data from the Vietnam Living Standard Measurement Survey.

Studies adopting the Theory of Planned Behavior (TPB) mostly use quantitative methods. Sometimes, however, researchers choose to use a qualitative method because of the nature of available data (e.g., interviews) or availability of only a limited number of cases. This paper describes a study in which the TPB was used with qualitative methods to explain differences in university teaching. It focuses primarily on the methods used: qualitative data coding, data analysis and interpretation, and methods for presenting and supporting results. The study explored factors which influence university teachers to adopt teaching models based on online social interaction when an e-learning platform is used to complement undergraduate classroom teaching. Participants were 26 university teachers (15 from Australia and 11 from Italy). They responded to a semi-structured interview based on the TPB. Three approaches to use of e-learning platforms were identified: upload of materials, use of discussion forums, and computer-supported collaborative learning (CSCL). Using this approach, it was possible to highlight substantial differences in the attitudes, social influence, and perceived behavioral control among the three groups.