A new spatial shift-share decomposition for the regional growth analysis: a local study of the employment based on Italian Business Statistical Register

This paper presents a new shift-share model to decompose the employment growth rate of a territorial unit by taking into consideration the association between industry mix and firm legal status effects measured in its neighborhood. We explicitly consider this kind of association to go beyond the problem of asymmetry found in a previous work. The empirical application refers to the data collected in the Italian Business Statistical Register and, in particular, regional employment figures in Friuli Venezia Giulia (NUTS2 level), for 219 territorial units (LAU2 level) and 12 Local Labour Systems (LLS), for the years 2001 and 2004.     

Maximum likelihood estimation of heterogeneous mixtures of Gaussian and uniform distributions

Existence and consistency of the Maximum Likelihood estimator of the parameters of heterogeneous mixtures of Gaussian and uniform distributions with known number of components are shown under constraints to prevent the likelihood from degeneration and to ensure identifiability. The EM-algorithm is discussed, and for the special case with a single uniform component a practical scheme to find a good local optimum is proposed. The method is compared theoretically and empirically to the estimation of a Gaussian mixture with “noise component” as introduced by Banfield and Raftery (1993) to find out whether it is a worthwhile alternative particularly in situations with outliers and points not belonging to the Gaussian components.     

《凤子》中反讽的各个侧面（下）

在《凤子》中,沈从文破除了归隐的基础、文化预设、物质可能和终极目的,涉及的是归隐的不可能性。沈从文以反讽为特色的隐士的归隐应当被理解为哲学和神秘意义上的归隐。沈从文的所有思考经过了反讽的筛选都被改头换面了,反讽性的超脱,相对于严肃的彻底超脱只是局部的。另外,这是一种双重的超脱：一方面,作者虽不乏公民与政治意识,但这却不成为一种崇拜;另一方面,生命的张力和对知识的相对化阻止了向神秘主义的转变。沈从文的人物并不逃避,他们生活在现实中。从根本上,沈从文将一个以极端化为特色的时代加以相对化。     

Approximating distributions of random functionals of Ferguson-Dirichlet priors

We explore the possibility of approximating the Ferguson-Dirichlet prior and the distributions of its random functionals through the simulation of random probability measures. The proposed procedure is based on the constructive definition illustrated in Sethuraman (1994) in conjunction with the use of a random stopping rule. This allows us to set in advance the closeness to the distributions of interest. The distribution of the stopping rule is derived, and the practicability of the simulating procedure is discussed. Sufficient conditions for convergence of random functionals are provided. The numerical applications provided just sketch the idea of the variety of nonparametric procedures that can be easily and safely implemented in a Bayesian setting.     

Extending the family of Bayesian bootstraps and exchangeable urn schemes

A Bayesian bootstrap for a finite population with censored observations is introduced. It is shown to reduce to the finite population Bayesian bootstrap if there is no censoring and to reduce to the censored data Bayesian bootstrap for a large population. A class of general urn schemes for simulating exchangeable sequences of variables is introduced which is connected to the bootstrap method.     

Influence of urbanization on the avian species-area relationship: insights from the breeding birds of Rome

Urban Ecosystems - The species-area relationship (SAR) is one of the most investigated patterns in ecology and conservation biology, yet there is no study testing how different levels of...     

Conjugate Priors Represent Strong Pre-Experimental Assumptions

Abstract.  It is well known that Jeffreys' prior is asymptotically least favorable under the entropy risk, i.e. it asymptotically maximizes the mutual information between the sample and the parameter. However, in this paper we show that the prior that minimizes (subject to certain constraints) the mutual information between the sample and the parameter is natural conjugate when the model belongs to a natural exponential family. A conjugate prior can thus be regarded as maximally informative in the sense that it minimizes the weight of the observations on inferences about the parameter; in other words, the expected relative entropy between prior and posterior is minimized when a conjugate prior is used.     

Military conscription and university enrolment: evidence from Italy

This paper analyses the effect of the abolition of compulsory military service (CMS) on university enrolment in Italy. A triple-difference model is used to account for various potentially confounding factors. The identification strategy exploits variation along three dimensions: (a) between gender, (b) between age-groups and (c) between time periods. The results show that there is no statistically significant evidence suggesting that the abolition of CMS has a causal effect on the decision to enrol in university studies. Estimates obtained employing a double-difference model exploiting variation along the dimensions (a) and (b) overestimate the effect. Finally, although there is no statistically significant overall effect, we find some evidence of heterogeneous effects between students from different social backgrounds.     

Sensory analysis via multi-block multivariate additive PLS splines

In the last decade, much effort has been spent on modelling dependence between sensory variables and chemical–physical ones, especially when observed at different occasions/spaces/times or if collected from several groups (blocks) of variables. In this paper, we propose a nonlinear generalization of multi-block partial least squares with the inclusion of variable interactions. We show the performance of the method on a known data set.