When an Event Makes a Difference

For (S, Σ) a measurable space, let and be convex, weak^* closed sets of probability measures on Σ. We show that if ∪ satisfies the Lyapunov property , then there exists a set A ∈ Σ such that min_μ1∈ μ₁(A) > max_μ2 ∈ (A). We give applications to Maxmin Expected Utility (MEU) and to the core of a lower probability.     

The effect of delaying motherhood on the second childbirth in Europe

We examine the effect of delaying motherhood on the transition to the second childbirth across European countries. There exist two opposite forces of delaying the first birth: biological and socio-cultural factors producing a postponement effect and career-related factors leading to a catch-up effect. Estimating a multistate duration model that addresses the endogeneity of age at first birth, we find a catch-up effect in countries where the career effect is large and a postponement effect in countries where the opportunity cost of childbearing is relatively high due to the lack of family friendly institutions and cultural influences, which may discourage late childbearing.     

Education,reputation or network? Evidence on migrant workers employability

The strong adverse selection that immigrants face in hosting labour markets may induce them to adopt some behaviours or signals to modify employers’ beliefs. Relevant mechanisms for reaching this purpose are personal reputation; exploiting ethnic networks deeply rooted in the hosting country; and high educational levels used as an indirect signal of productivity. On this last point, the immigrant status needs a stronger signal compared to that necessary for a native worker, and this may lead the immigrant to accept job qualifications which are lower than those achievable through the embodied educational level.The aim of the paper is to investigate whether the above mentioned mechanisms are adopted by immigrants in Italy, a crucial country for EU immigration flows, and if they are useful in increasing immigrants’ likelihood of employment. The empirical analysis has been conducted using the dataset from a national Labour Force Survey which provides information on thousands of documented immigrants. We estimate a logit model for immigrants’ likelihood of being employed, focusing on the above mentioned mechanisms: reputation, ethnic networks and educational level. Moreover we concentrate on the interaction effects of the mechanisms and investigate whether one of them wins on the others. Results show that each of the three mechanisms is statistically and economically significant and exerts positive influence: all factors contribute to increase the immigrant's probability of being employed. Anyway, a high level of education increases the probability of being employed more than the belonging to ethnic networks deeply rooted in Italy. The specific embodied capital of workers matter relatively more. This is relevant for labour public policies in this specific realm since the human capital lever is a possible direct target in various public policies and private human capital investments.     

Multivariate Markov switching dynamic conditional correlation GARCH representations for contagion analysis

This paper provides an extension of the Dynamic Conditional Correlation model of Engle (2002) by allowing both the unconditional correlation and the parameters to be driven by an unobservable Markov chain. We provide the estimation algorithm and perform an empirical analysis of the contagion phenomenon in which our model is compared to the traditional CCC and DCC representations. We acknowledge financial support from the Italian national research project on "The Euro and European financial market volatility: contagion, interdependence and volatility transmission" financed by the Italian Ministry of University and Research. Furthermore, we thank William De Pieri for research assistance and are grateful to Loriana Pelizzon, Claudio Pizzi, Domenico Sartore and the participants at the Forecasting Financial Markets 2004 conference and at the XLII Annual Meeting of the Italian Statistical Society for helpful comments. Usual disclaimer applies. Correspondence to: Monica Bilio     

Labour force participation and marital fertility of Italian women: The role of education

This paper uses data from the 1993 Survey of Household Income and Wealth conducted by the Bank of Italy in order to estimate a reduced form purist model of female marital fertility and labour force participation. It focuses in particular on the effect of formal education on both fertility and labour force participation, and accounts for the potential endogeneity of education. Our estimates show that increasing education up to the upper secondary level exerts ceteris paribus a positive effect on marital fertility at ages 21–39 and that highly educated women postpone fertility and have a higher labour market attachment.I wish to thank participants at the 15 ^th Annual Conference of the European Society for Population Economics 2001 (Athens), the 16 ^{t h} Italian Conference of Labour Economics 2001 (Florence), especially my discussant Emilia Del Bono, the Royal Economic Society Annual Conference 2002 (Warwick), Luca Mancini, Jeremy Smith and the anonymous referee of this Journal for useful comments. The usual disclaimer applies. The Bank of Italy is gratefully acknowledged as the original depository of the Survey of Household Income and Wealth data used in this paper. Funding from the Italian Ministry of University and Scientific Research (MURST) Project Too many or too few? The relationship between population dynamics and socio-economic development is also gratefully acknowledged. Responsible editor: Alessandro Cigno.     

Distribution of the C statistic with applications to the sample mean of Poisson data

The C statistic, also known as the Cash statistic, is often used in astronomy for the analysis of low-count Poisson data. The main advantage of this statistic, compared to the more commonly used χ2 statistic, is its applicability without the need to combine data points. This feature has made the C statistic a very useful method to analyze Poisson data that have small (or even null) counts in each resolution element. One of the challenges of the C statistic is that its probability distribution, under the null hypothesis that the data follow a parent model, is not known exactly. This paper presents an effort towards improving our understanding of the C statistic by studying (a) the distribution of C statistic for a fully specified model, (b) the distribution of C_min resulting from a maximum-likelihood fit to a simple one-parameter constant model, i.e. a model that represents the sample mean of N Poisson measurements, and (c) the distribution of the associated ΔC statistic that is used for parameter estimation. The results confirm the expectation that, in the high-count limit, both C statistic and C_min have the same mean and variance as a χ2 statistic with same number of degrees of freedom. It is also found that, in the low-count regime, the expectation of the C statistic and C_min can be substantially lower than for a χ2 distribution. The paper makes use of recent X-ray observations of the astronomical source PG 1116+215 to illustrate the application of the C statistic to Poisson data.     

Misspecification tests for periodic long memory GARCH models

Distributional theory for Quasi-Maximum Likelihood estimators in long memory conditional heteroskedastic models is not formally defined, even asymptotically. Because of that, this paper analyses the real size and power of the likelihood ratio and the Lagrange multiplier misspecification tests when periodic long memory GARCH models are involved. The performance of these tests is studied by means of Monte Carlo simulations with respect to the class of generalized long memory GARCH models. For this class of models, analytical derivatives are developed. An application to the USD/JPY exchange rate is also provided.     

Ageing,Health, Loneliness and Wellbeing

Social Indicators Research - Older people experience high rates of depression and suicide, yet they make a positive net contribution to the economy through activities such as employment,...