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El sistema escolar chileno escolariza de forma creciente a estudiantes migrantes, quienes asisten preferentemente a escuelas públicas, concentrándose en algunos establecimientos de ciertas comunas. Esta tendencia suele ser explicada por su patrón residencial, hipótesis que es analizada en este trabajo. Para ello se desarrolla un estudio cuantitativo que explota datos secundarios para escuelas que concentran estudiantes extranjeros y escuelas vecinas que no. Se concluye que ni el patrón residencial ni la dependencia administrativa explican la concentración de alumnado migrante y que en este fenómeno incidirían otras características de las escuelas, así como la acción de las familias.

A long tradition of research has shown that personality traits, such as extraversion and agreeableness, and interpersonal constructs better predict job performance with a tacit but not explicit distinction in sales marketing activities. In this contribution, we aim to understand the role of job-related and interest data, interpersonal, and personality traits in affecting either inbound or outbound marketing activities and the overall sales performance. An original questionnaire integrates the interpersonal traits and personality factors reported in the literature in sales marketing activities (independent variables). The results were matched with the individual job-related and interest data (control variables) and sales performance (criterion variables) - expressed as the total number of closed contracts over the inbound/outbound related contacts of employees with responsibility in marketing activities for a large banking group. We are able to identify the relevant predictors of sales performance by creating full binary trees using control and independent variables in conditional inference forests and variable importance index measures. Higher performers in either inbound or outbound marketing activities rely on distinct personality sub-traits, which have fundamentally essential implications for interpersonal functioning, and personal data when agreeableness is central to the ability to function effectively in the interpersonal realm of sales activity.

A deep comprehension of the vaginal ecosystem may hold promise for unraveling the pathophysiology of pregnancy and may provide novel biomarkers to identify subjects at risk of maternal-fetal complications. In this prospective study, we assessed the characteristics of the vaginal environment in a cohort of pregnant women throughout their different gestational ages and puerperium. Both the vaginal bacterial composition and the vaginal metabolic profiles were analyzed. A total of 63 Caucasian women with a successful pregnancy and 9 subjects who had a first trimester miscarriage were enrolled. For the study, obstetric examinations were scheduled along the three trimester phases (9-13, 20-24, 32-34 gestation weeks) and puerperium (40-55 days after delivery). Two vaginal swabs were collected at each time point, to assess the vaginal microbiome profiling (by Nugent score and 16S rRNA gene sequencing) and the vaginal metabolic composition (1H-NMR spectroscopy). During pregnancy, the vaginal microbiome underwent marked changes, with a significant decrease in overall diversity, and increased stability. Over time, we found a significant increase of Lactobacillus and a decrease of several genera related to bacterial vaginosis (BV), such as Prevotella, Atopobium and Sneathia. It is worth noting that the levels of Bifidobacterium spp. tended to decrease at the end of pregnancy. At the puerperium, a significantly lower content of Lactobacillus and higher levels of Gardnerella, Prevotella, Atopobium, and Streptococcus were observed. Women receiving an intrapartum antibiotic prophylaxis for Group B Streptococcus (GBS) were characterized by a vaginal abundance of Prevotella compared to untreated women. Analysis of bacterial relative abundances highlighted an increased abundance of Fusobacterium in women suffering a first trimester abortion, at all taxonomic levels. Lactobacillus abundance was strongly correlated with higher levels of lactate, sarcosine, and many amino acids (i.e., isoleucine, leucine, phenylalanine, valine, threonine, tryptophan). Conversely, BV-associated genera, such as Gardnerella, Atopobium, and Sneathia, were related to amines (e.g., putrescine, methylamine), formate, acetate, alcohols, and short-chain fatty-acids (i.e., butyrate, propionate).

Supplemental Material, sj-pdf-1-teu-10.1177_1354816620983131 for Dutch Disease phenomenon and demand for international business travels: Panel ARDL/PMG estimation by Hassan F Gholipour, Reza Tajaddini and Usama Al-mulali in Tourism Economics

Supplemental Material, sj-pdf-1-teu-10.1177_1354816620987198 for Semiparametric APC analysis of destination choice patterns: Using generalized additive models to quantify the impact of age, period, and cohort on travel distances by Maximilian Weigert, Alexander Bauer, Johanna Gernert, Marion Karl, Asmik Nalmpatian, Helmut Küchenhoff and Jürgen Schmude in Tourism Economics

Supplemental Material, sj-pdf-3-teu-10.1177_1354816620987198 for Semiparametric APC analysis of destination choice patterns: Using generalized additive models to quantify the impact of age, period, and cohort on travel distances by Maximilian Weigert, Alexander Bauer, Johanna Gernert, Marion Karl, Asmik Nalmpatian, Helmut Küchenhoff and Jürgen Schmude in Tourism Economics

Gardnerella vaginalis (GV) is an anaerobic bacterial species involved in the pathogenesis of bacterial vaginosis (BV), a condition of vaginal dysbiosis associated with adverse pregnancy outcomes. GV strains are categorized into four clades, characterized by a different ability to produce virulence factors, such as sialidase. We investigated the distribution of GV clades and sialidase genes in the vaginal ecosystem of a cohort of pregnant women, assessing the correlations between GV clades and the whole vaginal microbiome. A total of 61 Caucasian pregnant women were enrolled. Their vaginal swabs, collected both at the first and third trimester of pregnancy, were used for (i) evaluation of the vaginal status by Nugent score, (ii) vaginal microbiome profiling by 16S rRNA sequencing, (iii) detection and quantification of GV clades and sialidase A gene by qPCR assays. DNA of at least one GV clade was detected in most vaginal swabs, with clade 4 being the most common one. GV clade 2, together with the presence of multiple clades (>2 simultaneously), were significantly associated with a BV condition. Significantly higher GV loads and sialidase gene levels were found in BV cases, compared to the healthy status. Clade 2 was related to the major shifts in the vaginal microbial composition, with a decrease in Lactobacillus and an increase in several BV-related taxa. As the number of GV clades detected simultaneously increased, a group of BV-associated bacteria tended to increase as well, while Bifidobacterium tended to decrease. A negative correlation between sialidase gene levels and Lactobacillus, and a positive correlation with Gardnerella, Atopobium, Prevotella, Megasphaera, and Sneathia were observed. Our results added knowledge about the interactions of GV clades with the inhabitants of the vaginal microbiome, possibly helping to predict the severity of BV and opening new perspectives for the prevention of pregnancy-related complications.

This study explores the downsizing propensity of family and non-family firms by considering their territorial embeddedness during both periods of economic stability and financial crisis. By drawing on a panel dataset of Spanish manufacturing firms for the period 2002–2015, we show that, all things being equal, family firms have a lower propensity to downsizing than non-family firms. When considering the effect of territorial embeddedness, we found that territorially embedded family firms have an even lower propensity to downsizing than their non-family counterparts. Furthermore, the concern of territorially embedded family firms for their employees’ welfare was particularly pronounced during the years of the global financial crisis. This result is explained by the existence of socially proximate relationships with the firms’ immediate surroundings, based on similarity and a sense of belonging, which push deeply rooted family firms to treat their employees as salient stakeholders during hard times. Overall, our study stresses the importance of local roots in moderating the relationship between family firms and downsizing.

Increased incidence rates of amyotrophic lateral sclerosis (ALS) have been recently reported across various Western countries, although geographic and temporal variations in terms of incidence, clinical features and genetics are not fully elucidated. This study aimed to describe demographic, clinical feature and genotype–phenotype correlations of ALS cases over the last decade in the Emilia Romagna Region (ERR). From 2009 to 2019, our prospective population-based registry of ALS in the ERR of Northern Italy recorded 1613 patients receiving a diagnosis of ALS. The age- and sex-adjusted incidence rate was 3.13/100,000 population (M/F ratio: 1.21). The mean age at onset was 67.01 years; women, bulbar and respiratory phenotypes were associated with an older age, while C9orf72-mutated patients were generally younger. After peaking at 70–75 years, incidence rates, among women only, showed a bimodal distribution with a second slight increase after reaching 90 years of age. Familial cases comprised 12%, of which one quarter could be attributed to an ALS-related mutation. More than 70% of C9orf72-expanded patients had a family history of ALS/fronto-temporal dementia (FTD); 22.58% of patients with FTD at diagnosis had C9orf72 expansion (OR 6.34, p = 0.004). In addition to a high ALS incidence suggesting exhaustiveness of case ascertainment, this study highlights interesting phenotype–genotype correlations in the ALS population of ERR.

This research presents the application of a beam finite element, specifically derived for simulating bending–torsion coupling in equivalent box-beam structures with curvilinear stiffeners. The stiffener path was simulated and optimized to obtain an expected coupling effect with respect to four typical static load cases, including geometric constraints related to the additive manufacturing production method. The selected load condition was applied to the centroid of the beam section, and the structure performance was consequently determined. A variation in load position up to one-fourth of the beam width was considered for investigating the stiffener path variation corresponding to a minimum bending–torsion coupling effect. The results demonstrated the capability of such a beam finite element to correctly represent the static behavior of beam structures with curvilinear stiffeners and show the possibility to uncouple its bending–torsion behavior using a specific stiffener orientation. The simulation of a laser powder bed fusion process showed new opportunities for the application of this technology to stiffened panel manufacturing.

During pregnancy, the vaginal ecosystem undergoes marked changes, including a significant enrichment with Lactobacillus spp. and profound alterations in metabolic profiles. A deep comprehension of the vaginal environment may shed light on the physiology of pregnancy and may provide novel biomarkers to identify subjects at risk of complications (e.g., miscarriage, preterm birth). In this study, we characterized the vaginal ecosystem in Caucasian women with a normal pregnancy (n = 64) at three different gestational ages (i.e., first, second and third trimester) and in subjects (n = 10) suffering a spontaneous first trimester miscarriage. We assessed the vaginal bacterial composition (Nugent score), the vaginal metabolic profiles (1H-NMR spectroscopy) and the vaginal levels of two cytokines (IL-6 and IL-8). Throughout pregnancy, the vaginal microbiota became less diverse, being mainly dominated by lactobacilli. This shift was clearly associated with marked changes in the vaginal metabolome: over the weeks, a progressive reduction in the levels of dysbiosis-associated metabolites (e.g., biogenic amines, alcohols, propionate, acetate) was observed. At the same time, several metabolites, typically found in healthy vaginal conditions, reached the highest concentrations at the end of pregnancy (e.g., lactate, glycine, phenylalanine, leucine, isoleucine). Lower levels of glucose were an additional fingerprint of a normal vaginal environment. The vaginal levels of IL-6 and IL-8 were significantly associated with the number of vaginal leukocytes, as well as with the presence of vaginal symptoms, but not with a condition of dysbiosis. Moreover, IL-8 concentration seemed to be a good predictor of the presence of vaginal Candida spp. Cytokine concentrations were negatively correlated to lactate, serine, and glycine concentrations, whereas the levels of 4-hydroxyphenyllactate, glucose, O-acetylcholine, and choline were positively correlated with Candida vaginal loads. Finally, we found that most cases of spontaneous abortion were associated with an abnormal vaginal microbiome, with higher levels of selected metabolites in the vaginal environment (e.g., inosine, fumarate, xanthine, benzoate, ascorbate). No association with higher pro-inflammatory cytokines was found. In conclusion, our analysis provides new insights into the pathophysiology of pregnancy and highlights potential biomarkers to enable the diagnosis of early pregnancy loss.

Vaginal microbes and their metabolic products have crucial functions, affecting local immunity development and maternal-fetal health. The composition of the vaginal microbiome can vary in response to various factors, including body mass index (BMI), and diet. In this study we get new insights into the vaginal ecosystem of Caucasian women (n = 24) at the first trimester of pregnancy, assessing whether pre-pregnancy diet can affect the structure of the vaginal environment in terms of bacterial composition and vaginal metabolite concentration. We characterized 1) the vaginal bacterial composition (Nugent score), 2) the vaginal metabolic profiles (1H-NMR spectroscopy), and 3) the dietary nutrient intake by means of a validated food frequency questionnaire. Pre-pregnancy BMI was negatively related to vaginal health status, indicating that women who begin pregnancy overweight/obese have a greater occurrence of vaginal dysbiosis during pregnancy. A lactobacilli-dominated vaginal microbiota was negatively associated with higher pre-pregnancy intake of animal-sourced protein. Conversely, a higher pre-pregnancy consumption of total carbohydrates and sugars seemed to be a protective factor for vaginal health. The vaginal environment of BV-women was characterized by higher levels of biogenic amines and organic acids, whereas higher levels of phenylpropionate and diverse amino acids were fingerprints of a healthy vaginal status. A significant association between a higher pre-pregnancy BMI and several dysbiosis-related vaginal metabolites was also found. Our study shed light on the role of pre-pregnancy BMI and diet on the vaginal environment during pregnancy, underlining the importance of limiting protein intake from animal foods to maintain a healthy lactobacilli-dominated microbiota.

Supplemental Material, sj-pdf-1-teu-10.1177_1354816621993627 for How does institutional quality moderates the impact of tourism on economic growth? Startling evidence from high earners and tourism-dependent economies by Festus Fatai Adedoyin, Naila Erum and Festus Victor Bekun in Tourism Economics

In 2015, the United Nations established 17 Sustainable Development Goals (SDGs) to be reached by 2030. They are aimed at all members of society, including businesses, which could integrate SDGs within their Corporate Social Responsibility (CSR) strategies. As family firms constitute the most widespread form of business, understanding the factors that drive the decisions to pursue SDGs is essential. Thus, this research aims to understand why a family firm complies with SDGs. Additionally, it examines how SDGs enter, at the strategic level, activities and management practices. Following the case study method, the paper focuses on a family firm based in Italy, by means of documentary analysis, semi-structured interviews, and online data. In line with the Socioemotional Wealth (SEW) theory, family and personal values are crucial. While SDGs are only now entering the strategic level, their rationale has always been part of the family values, and the firm’s culture. The selected firm is pursuing ten Goals. SDGs serve as a further motivator for family firms to behave more responsibly, meaning that they help to align the firm’s strategy with the global challenges, building on existing family and firm’s values. \ud Our paper brings several contributions to the family business, CSR and SDGs literature, providing a representation of the reasons why a family firm pursues SDGs and the first reaction phases to SDGs. It brings practical implications for policymakers, highlighting the role of family values as the main drivers of the choice to invest in SDGs. By providing unique evidence, it is the first to connect the family business literature, CSR and SDGs.

The inhabitants of the vaginal ecosystem can harbor genetic determinants conferring antimicrobial resistance. However, detailed data about the distribution of resistance genes in the vaginal microbiome of pregnant women are still lacking. Therefore, we assessed the presence of macrolide (i.e., erm genes) and tetracycline (i.e., tet genes) resistance markers in the vaginal environment of Caucasian women at different gestational ages. Furthermore, the detection of resistance genes was related to the composition of the vaginal microbiota. A total of 228 vaginal samples, collected at different trimesters of pregnancy or during the puerperium, were tested for the presence of ermB, ermF, tet(W), and tet(M) by in-house end-point PCR assays. The composition of the vaginal microbiota was assessed through a microscopic evaluation (i.e., Nugent score) and by means of sequencing V3–V4 hypervariable regions of the bacterial 16 rRNA gene. Overall, the most detected resistance gene was tet(M) (76.7%), followed by ermB (55.2%). In 17% of women, mainly with a ‘normal’ vaginal microbiota, no resistance genes were found. Except for tet(W), a significant correlation between the positivity of resistance genes and a dysbiotic vaginal status (i.e., bacterial vaginosis (BV)) was noticed. Indeed, samples positive for at least one resistance determinant were characterized by a decrease in Lactobacillus spp. and an increase of BV-related genera (Prevotella, Gardnerella, Atopobium, Sneathia). A high predominance of vaginal Lactobacillus spp. (>85%) was associated with a lower risk of tet(W) gene detection, whereas the presence of Megasphaera (>1%) increased the risk of positivity for all analyzed genes. Different types of vaginal microbiota are associated with peculiar resistance profiles, being a lactobacilli-dominated ecosystem poor in or free of resistance genes. These data could open new perspectives for promoting maternal and neonatal health.

Consistent with the social and institutional paradigm, countries with similar cultures, such as Italy and Spain, may show similar trends in the development of accounting research. This article develops a Comparative International Accounting History perspective, which is aimed at comparing accounting history subjects and themes in different countries. This research analyses publication patterns in accounting, understanding emerging topics and fields. It compares the last 20 years of Italian and Spanish accounting journals, developing a content analysis of each issue in the 20-year time frame from 1994 to 2014. Highlighting common trends and insights, this article adds to previous literature that examines publishing patterns of research in accounting journals from a historical point of view. It demonstrates that accounting research is developing beyond the institutional paradigm, showing an internationalisation process and trends consistent with Anglo-Saxon Journals.

The influence of die wall lubrication during warm die compaction on densification, microstructure and mechanical properties of three low alloy ferrous powders was investigated. Specimens were sintered at 1250°C. Die wall lubrication leads to higher green and sintered density and enhances the dimensional stability. It does not affect the microstructure of the matrix, while pores are smaller and more rounded than in bulk lubricated specimens. In TRS tests, both strength and deformation are higher in die wall lubricated specimens than bulk lubricated ones.

This paper employs the most recent Input Output tables to discuss the Italian lockdown after the COVID-19 epidemics. We define “basic activities” and derive a ranking of industries which more intensively contribute to them. Confronting our results with the choices of the Italian government, we find that these were broadly correct in terms of industrial composition. However, we find that the lockdown of industries such as construction, real estate and manufacture of basic metals reveal a very conservative preferences in terms of the target share of output of essential activities (below 85 %).

Supplemental material, sj-pdf-1-jtr-10.1177_00472875211028322 for Estimating the Economic Impact of Tourism in the European Union: Review and Computation by Paolo Figini and Roberto Patuelli in Journal of Travel Research

Over the past decades, leisure travel has become increasingly popular in older segments of the world population, as a consequence of global factors such as a rise in life expectancy, improved health conditions, a higher disposable income and increased availability of discretionary time in retirement age. Consequently, researchers have become more interested in studying the motivations for travel of seniors. A number of questions may be raised or have been addressed in the recent past: What are the main factors explaining the travelling choices of seniors? Are their travel motivations different from the ones of the general population, which have been widely studied in the past? Are geographical differences in terms of motivations comparable between different age groups? Why is senior tourism a topic of particular interest with regard to Asia? In order to answer such questions, in this article, we provide a review of the literature on the travel motivations of seniors. On the basis of 29 articles published between 1988 and 2015 on the topic, we present a qualitative and meta-analytic assessment of past findings, by investigating the dimensions of travel motivations most frequently identified in past seniors surveys. Finally, we discuss a research agenda for further analysis of senior travel motivations and for the integration of this branch of travel research within the wider framework of senior tourism analysis and management.

The present research is aimed at analysing the role of the State towards the first British and Italian railway companies before the nationalisations. The article reviews the British and Italian railway legislation and financial reports, retrieved from historical archives. The results highlight two very different roles of the public institutions: while one State acted as a regulator, the other one mainly acted as an entrepreneur.

According to a recent trend of research, there is a growing interest in applications of machine learning techniques to business analytics. In this work, both supervised and unsupervised machine learning techniques are applied to the analysis of a dataset made of both family and non-family firms. This is worth investigating, because the two kinds of firms typically differ in some aspects related to performance, which can be reflected in balance sheet data. First, binary classification techniques are applied to discriminate the two kinds of firms, by combining an unlabeled dataset with the labels provided by a survey. The most important features for performing such binary classification are identified. Then, clustering is applied to highlight why supervised learning can be effective in the previous task, by showing that most of the largest clusters found are quite unequally populated by the two classes.

Literature on the formation of intention toward entrepreneurship in adolescents has focused on either parental (vertical) transmission of social capital or network effects from peers or neighbours (horizontal). Considering the simultaneous effect of parents, peers, and neighbours, we suggest that such three levels identify a mechanism whereby the individual perception of their importance interacts with their objective characteristics. With a unique dataset for second-year high-school adolescents in the Italian city of Palermo, and employing Logit and 3SLS methods, we find evidence for a strong parental effect and for secondary peer (peers) effects on student intention. We also detect clear endogenous effects from the neighbourhood and the overall context. Moreover, entrepreneurship is confirmed to be perceived, even by high-school students, as a buffer for possible unemployment and social mobility.

Tendenze nella ricerca di ragioneria: un’analisi degli ultimi 20 anni in Italia La presente ricerca intende illustrare l’avanzamento delle ricerche in tema di ragioneria in Italia, identificandone le principali tendenze negli ultimi vent’anni. In tale periodo, infatti, la ricerca nazionale inizia ad aprirsi al contesto internazionale, contemporaneamente ad alcuni cambiamenti sviluppatisi nell’accademia italiana. Il presente lavoro sviluppa una content analysis di oltre 1000 articoli della piu antica rivista italiana di ragioneria, RIREA (Rivista Italiana di Ragioneria e di Economia Aziendale). In particolare, si analizzano i cambiamenti negli autori, nelle tematiche trattate, negli intervalli temporali e nei luoghi studiati, estendendo framework italiani e internazionali. I risultati principali mostrano una progressiva internazionalizzazione degli autori e delle tematiche trattate. Infine, le riflessioni conclusive potranno essere utili agli studiosi e ai ricercatori della disciplina.

The paper presents an on-going activity for the development of a joint laboratory between University of Genova and ABB for training and research within the context of the shipboard power systems. In particular the laboratory has been installed for training courses to satisfy the HV requirements laid out in the Standards of Training, Certification and Watchkeeping (STCW), Manila Amendments. It has been approved by the Italian Minister of Transportation, decree 15th February 2016 (16A01447). The course defines the mandatory knowledge and training to meet the competence for management of marine High Voltage electrical installations, for engine officers designed to work on vessels equipped with High Voltage devices (>1000V) and Electro Technical Officers (ETO), as per sections A-III/2, AIII/3 e A-III/6 of STCW code. Further, the laboratory and the research activities have been developed towards two main directions. The first aspect is related to the development of Microgrid models in a dedicated platform (OPAL-RT) for Hardware-in-The-Loop (HIL) testing of LV breakers and PMS (Power management system) applications. The second objective is the development of a real small-scale shipboard power system with two emulated gensets rated 7 kVA and different AC drives and loads for training purpose and validation of controllers.

This paper analyses recent tendencies of managing public real estate and public stake-holdings in a sample of Italian municipalities. The data, retrieved from the Italian Ministry of Interior (Central Department of Local Finances), has been analysed to understand if the local public group, intended in a wider sense and including both subsidiaries and real estate property, is changed over time, in terms of size and composition. The first results show that there has not been adequate divestment to postulate on a general reduction of the boundaries of the “Integrated” Public Groups.

The present book is concerned with spatial interaction modelling. In particular, it aims to illustrate, through a collection of methodological and empirical studies, how estimation approaches in this field recently developed, by including the tools typical of spatial statistics and spatial econometrics (Anselin 1988; Cressie 1993; Arbia 2006, 2014), into what LeSage and Pace (2009) deemed as ‘spatial econometric interaction models’.

Monoclinic celsian derived from an innovative route, i.e. cation exchanged zeolites heat-treated at low temperature, was added at different contents (10, 20, 30 wt%) to a glass matrix, in order to improve its mechanical and electrical performances. The effect of the celsian reinforcement was evaluated by testing several properties of the composite materials, such as the elastic modulus, abrasion resistance, flexural strength and electrical insulation. The results so far obtained suggest that the addition of the monoclinic celsian to the glass matrix may produce low-cost particulate composites with interesting technological properties.

The analysis of complex networks has recently received considerable attention. The work by Albert and Barabási presented a research challenge to network analysis, that is, growth of the network. The present paper offers a network analysis of the spatial commuting network in Germany. First, we study the spatial evolution of the commuting network over time. Secondly, we compare two spatial interaction model (SIM) specifications, in order to replicate the actual network structure. Our findings suggest that the commuting network appeared to become more dense and clustered, while the SIMs seem to require more sophisticated specifications, in order to replicate such a connectivity structure. © Springer Science+Business Media, LLC 2007.

The thermal endurance of nanocomposites based on isotactic poly(propylene) filled with nanosilicates, is evaluated by a short-term analytical procedure. The procedure is based on oxidative stability measurements by isothermal thermogravimetric analysis in a pure oxygen flow, over the temperature range form 120 to 150 degC, and provides the activation energy of the thermo-oxidative degradation process. The activation energy values thus obtained were compared with those derived by scanning thermogravimetric analysis at different heating rates. The thermal endurance lines for the investigated materials can be drawn with the aid of a conventional life test, based on weight loss measurement as a function of aging time, according to the IEC 60216 procedure. A noticeable increase of the thermal endurance of the isotactic poly(propylene) based nanocomposite with respect to the unmodified polymer is found out.

In this paper, a set of neural network (NN) models is developed to compute short-term forecasts of regional employment patterns in Germany. Neural networks are modern statistical tools based on learning algorithms that are able to process large amounts of data. Neural networks are enjoying increasing interest in several fields because of their effectiveness in handling complex data sets when the functional relationship between dependent and independent variables is not specified explicitly. The present paper compares two NN methodologies. First, it uses NNs to forecast regional employment in both the former West and East Germany. Each model implemented computes single estimates of employment growth rates for each German district, with a 2-year forecasting range. Next, additional forecasts are computed, by combining the NN methodology with shift-share analysis (SSA). Since SSA aims to identify variations observed among the labour districts, its results are used as further explanatory variables in the NN models. The data set used in our experiments consists of a panel of 439 German (NUTS 3) districts. Because of differences in the size and time horizons of the data, the forecasts for West and East Germany are computed separately. The out-of-sample forecasting ability of the models is evaluated by means of several appropriate statistical indicators.

Recent works indicate that polypropylene (PP) and ethylene-vinylacetate (EVA) filled by nanosilicates may present low content of space charge and high electric strength. Investigations are being made to explain nanocomposite behaviour and characterize their electrical, thermal and mechanical properties. In this paper, the results of broad-band dielectric spectroscopy performed on EVA and PP filled by layered nanosized silicates are reported. Isochronal and isothermal curves of complex permittivity, as well as activation energies of the relaxation processes, are presented and discussed. Nanostructuration gives rise to substantial changes in the polarisation and dielectric loss behaviour. While the relaxation process of EVA, associated with glass transition of the material amorphous phase, results unchanged from base to nanostructured material, nanocomposites EVA and PP have shown the rise of a new process at higher temperatures respect to the typical host material processes, as well as a different distribution of relaxation processes. Changes in space charge accumulation in relation to the effectiveness of the purification process performed upon nanostructured materials are also reported: while the dispersion of the clean clays leads to a reduction of the space charge, especially at high fields, an unclean filler gives rise to significant homo-charge accumulation and interfacial polarisation phenomena.

(Spatial) panel data are routinely modeled in discrete time (DT). However, compelling arguments exist for continuous-time (CT) modeling of (spatial) panel data. Particularly, most social processes evolve in CT, so that statistical analysis in DT is an oversimplification, gives an incomplete representation of reality, and may lead to misinterpretation of estimation results. The most compelling reason for a CT approach is that, in contrast to DT modeling, it allows adequate modeling of dynamic adjustment processes. This article introduces spatial dependence in a CT modeling framework. We propose a nonlinear structural equation model (SEM) with latent variables for estimation of the exact discrete model (EDM), which links CT model parameters to DT observations. The use of a SEM with latent variables enables a specification that accounts for measurement errors in the variables, leading to a reduction of attenuation bias (i.e., disattenuation). The SEM-CT model with spatial dependence developed here is the first dynamic SEM with spatial dependence. A simple regional labor market model for Germany, comprising changes in unemployment and population as endogenous state variables, and changes in regional average wages and in the structure of the manufacturing sector as exogenous input variables, illustrates this spatial econometric SEM-CT framework.

Research and development (R&D), in the field of nanomaterials is expected to be a major driver of innovation and economic growth. Consequently, it is of great interest to understand which factors facilitate the creation of new technological knowledge. The existing literature has typically addressed this question by employing a knowledge production function based on firm-, regional- or even country-level data. Estimating the effects for the entire national system of innovation, however, assumes poolability of regional data. We apply our reasoning to Germany, which has well-known regional disparities, in particular between the East and the West. Based on analyses at the NUTS 3 regional level, we find different knowledge production functions for the East and the West. Moreover, we investigate how our results are affected by the adoption of alternative aggregation levels. Overall, our findings suggest that a careful evaluation of poolability and aggregation is required before estimating knowledge production functions at the regional level.

Intention toward any occupational choice can be widely categorized as a rational choice process combined with a subjective attitude function. There is extensive literature dealing with the formation of intention toward entrepreneurship in adolescents, in particular as a result of either parental (vertical) transmission of social capital or network effects from peers or neighbours (the latter two being two different levels of horizontal transmission varying in proximity in terms of bonding and bridging). We contribute to this literature by considering the joint effect of all these three levels simultaneously, in order to avoid an underspecification of the model due to omission of important cultural factors. We hypothesize that such three levels identify a mechanism where the individual perception of their importance interacts with their objective characteristics. With data for second-year high-school students, and employing empirical triangulation through Logit and 3SLS methods, we find evidence for a strong parental effect and of secondary peer effects on student intention. We also detect clear endogenous effects from the neighbourhood and the overall cultural context. Moreover, entrepreneurship is confirmed to be perceived, even by students, as a buffer for unemployment and social mobility.

Nonlinear estimation of the gravity model with Poisson/negative binomial methods has become popular to model international trade flows, because it permits a better accounting for zero flows and extreme values in the distribution tail. Nevertheless, as trade flows are not independent from each other due to spatial autocorrelation, these methods may lead to biased parameter estimates. To overcome this problem, eigenvector spatial filtering variants of the Poisson/negative binomial specification have been proposed in the literature of gravity modelling of trade. However, no specific treatment has been developed for cases in which many zero flows are present. This paper contributes to the literature in two ways. First, by employing a stepwise selection criterion for spatial filters that is based on robust (sandwich) p-values and does not require likelihood-based indicators. In this respect, we develop an ad hoc backward stepwise function in R. Second, using this function, we select a reduced set of spatial filters that properly accounts for importer-side and exporter-side specific spatial effects, both at the count and the logit processes of zero-inflated methods. Applying this estimation strategy to a cross-section of bilateral trade flows between a set of worldwide countries for the year 2000, we find that our specification outperforms the benchmark models in terms of model fitting, both considering the AIC and in predicting zero (and small) flows.

none 2 si Empirical assessments of the forecasting power of spatial panel data econometric models are still scarcely available. Moreover, several methodological contributions rely on simulated data to showcase the potential of proposed methods. While simulations may be useful to evaluate the properties of a single estimator, the empirical set-ups of simulation studies are often based on strong assumptions regarding the shape and regularity of the statistical distribution of the variables involved. It is then valuable to have, next to simulation studies, empirical assessments of competing econometric models based on real data. In this paper, we evaluate competing spatial (dynamic) panel methods, selecting a number of data sets characterized by a range of different cross-sectional and temporal dimensions, as well as different levels of spatial autocorrelation. We carry out our empirical exercise on regional unemployment data for France, Spain and Switzerland. Additionally, we test different forecasting horizons, in order to investigate the speed of deterioration of forecasting quality. We compare two classes of methods: spatial vector autoregressive (SpVAR) models and dynamic panel models making use of eigenvector spatial filtering (SF). We find that, as it could be expected, the unbalance between the temporal and cross-sectional dimension (T >> n) does play in favour of the SpVAR model. On the other hand, the advantage of the SpVAR model over the SF model appears to diminish as the forecasting horizon widens, eventually leading the SF model to being preferred for more distant forecasts. mixed M. Mayor; R. Patuelli M. Mayor; R. Patuelli

Bilateral trade flows traditionally have been analysed by means of the spatial interaction gravity model. Still, (auto)correlation of trade flows has only recently received attention in the literature. This paper takes up this thread of emerging literature, and shows that spatial filtering (SF) techniques can take into account the autocorrelation in trade flows. Furthermore, we show that the use of origin and destination specific spatial filters goes a long way in correcting for omitted variable bias in an otherwise standard empirical gravity equation. For a cross-section of bilateral trade flows, we compare an SF approach to two benchmark specifications that are consistent with theoretically derived gravity. The results are relevant for a number of reasons. First, we correct for autocorrelation in the residuals. Second, we suggest that the empirical gravity equation can still be considered in applied work, despite the theoretical arguments for its misspecification due to omitted multilateral resistance terms. Third, if we include SF variables, we can still resort to any desired estimator, such as OLS, Poisson or negative binomial regression. Finally, interpreting endogeneity bias as autocorrelation in regressor variables and residuals allows for a more general specification of the gravity equation than the relatively restricted theoretical gravity equation. In particular, we can include additional country-specific push and pull variables, besides GDP (e.g., land area, landlockedness, and per capita GDP). A final analysis provides autocorrelation diagnostics according to different candidate indicators.

In this paper we empirically assess the evolution for the EU regions of both employment and unemployment before and after the Global Crisis. After a review of the literature on the theories and key determinants of regional unemployment, we shall overview the main findings concerning the labour market impact of the Global Crisis. The empirical analysis will initially be carried out at the national level including all EU countries; subsequently, we shall focus on the EU regions (at the NUTS-2 level), in order to detect possible changes in the dispersion of regional unemployment rates after the crisis. Our econometric investigations aim to assess the effect, on labour market performance, of previous developments in regional labour markets time series, as well as the importance of structural characteristics of the labour markets, in terms of the sectoral specialization of the regional economies. In fact, the local industry mix may have played a crucial role in shaping labour market performance in response to the crisis. In addition, we consider further characteristics of the regional labour markets, by including indicators of the level of precarization of labour and of the share of long-term unemployed, as indicators of the efficiency of the local labour markets. From a methodological viewpoint, we exploit eigenvector decomposition-based spatial filtering techniques, which allow us to greatly reduce unobserved variable bias – a significant problem in cross-sectional models – by including indicators of latent unobserved spatial patterns. Finally, we render a geographical description of the heterogeneity influence of past labour market performance over the crisis period, showing that the past performance has a differentiated impact on recent labour market developments.

En el artículo se aborda la calidad de la educación en el 2º Medio mediante el análisis de la eficiencia de los colegios y liceos. Se utilizan los datos de la prueba nacional SIMCE de 2º Medio de 1994, 1998 y 2001. La eficiencia se calcula mediante regresión lineal múltiple de la eficacia (logro escolar = resultados SIMCE), con control de variables de input: inversión por alumno, nivel educativo de los padres y vulnerabilidad educativa. Los resultados SIMCE dependen en un 69% de las tres variables de input estudiadas, siendo imputable a los centros escolares en un 31 %. Las diferencias en eficiencia entre las redes pública y privada apenas alcanza a 1.75 puntos promedio (hay que tener en cuenta que no se ha podido controlar la selección de alumnos por los centros). Los centros financiados con fondos públicos son los que muestran un progreso en su eficiencia en el estudio longitudinal, especialmente los municipales. Los resultados apuntan a que el mercado en la educación no está justificado empíricamente para mejorar la calidad y eficiencia en la educación, aunque si para generar negocios con la educación.

Bilateral trade flows traditionally have been analysed by means of the spatial interaction gravity model. Still, (auto)correlation of trade flows has only recently received attention in the literature. This paper takes up this thread of emerging literature, and shows that spatial filtering (SF) techniques can take into account the autocorrelation in trade flows. Furthermore, we show that the use of origin and destination specific spatial filters goes a long way in correcting for omitted variable bias in an otherwise standard empirical gravity equation. For a cross-section of bilateral trade flows, we compare an SF approach to two benchmark specifications that are consistent with theoretically derived gravity. The results are relevant for a number of reasons. First, we correct for autocorrelation in the residuals. Second, we suggest that the empirical gravity equation can still be considered in applied work, despite the theoretical arguments for its misspecification due to omitted multilateral resistance terms. Third, if we include SF variables, we can still resort to any desired estimator, such as OLS, Poisson or negative binomial regression. Finally, interpreting endogeneity bias as autocorrelation in regressor variables and residuals allows for a more general specification of the gravity equation than the relatively restricted theoretical gravity equation. In particular, we can include additional country-specific push and pull variables, besides GDP (e.g., land area, landlockedness, and per capita GDP). A final analysis provides autocorrelation diagnostics according to different candidate indicators.