The association between two random elements: A complete characterization and odds ratio models

For random elements X and Y (e.g. vectors) a complete characterization of their association is given in terms of an odds ratio function. The main result establishes for any odds ratio function and any pre-specified marginals the unique existence of a corresponding joint distribution (the joint density is obtained as a limit of an iterative procedure of marginal fittings). Restricting only the odds ratio function but not the marginals leads to semi-parmetric association models for which statistical inference is available for samples drawn conditionally on either X or Y. Log-bilinear association models for random vectors X and Y are introduced which generalize standard (regression) models by removing restrictions on the marginals. In particular, the logistic regression model is recognized as a log-bilinear association model. And the joint distribution of X and Y is shown to be multivariate normal if and only if both marginals are normal and the association is log-bilinear.Acknowledgements The author thanks both referees for their helpful comments which improved the first draft of the paper.     

Volatility linkages in the spot and futures market in Australia: a copula approach

To better characterize the dependence structure of the joint returns distribution, we propose to blend copula functions with Asymmetric GARCH (AGARCH) models, which are allowed for generalized error distribution. We model the copula’s marginals by the AGARCH processes that can differentiate between the impacts of positive and negative shocks on the returns volatility while taking the large kurtosis of the returns into account. An application of the procedure is elaborated on the All Ordinaries Index and its corresponding Share Price Index on future contracts in Australia. The findings reveal that the two spot and future markets show a strong right tail dependence but no left tail dependence. This provides a very useful knowledge for the risk management and hedging in futures markets.     

Understanding graduate recruitment,development and retention for the enhancement of talent management: sharpening ‘the edge’ of graduate talent

Graduates are deemed to be a key source of talent within many organisations and thus recruiting, developing and retaining them is viewed as a logical talent management (TM) strategy. However, there has been little attention paid to university graduates as part of an organisation’s TM strategy. Such a specific focus addresses the need for further research into the segmentation of talent pools and the specific challenges different talent pools are likely to create. This research, which utilised a qualitative data collection strategy, examined the experiences and practices of six large UK organisations in relation to graduate TM. Drawing from Gallardo-Gallardo, Dries and González-Cruz’s (2013. What is the meaning of ‘talent’ in the world of work? Human Resource Management Review, 23, 290–300.) framework for the conceptualisation of talent, the findings from this research indicate and explain why graduate employers are frequently compelled to use the object approach (talent as characteristics of people) due to the unique characteristics that recent graduates possess, even though other studies have found that a subject approach (talent as people and what they do) is preferred by most employers. Ultimately, employers conceptualise graduate talent by what they describe as ‘the edge’ which needs to be ‘sharpened’ to fully realise the potential that graduates offer.     

Improving the J Test in the SARAR Model by Likelihood-based Estimation

Abstract

It has been demonstrated recently that in small-to-medium samples the empirical significance levels of the asymptotic J-type tests for the SARAR model introduced by Kelejian (2008) can be controlled in many cases by the use of a bootstrap to construct a reference distribution. A feature of the popular GMM estimator in this context that deserves to receive more attention is that in small samples it will often deliver spatial parameter estimates that lie outside the invertibility region of the model. Using such illegitimate estimates to construct bootstrap samples is then problematic; the present paper finds that this practical obstacle may be removed by the use of quasi-maximum likelihood estimates that guarantee invertibility. The effects of different spatial weight patterns and sample size on the empirical significance levels and power of the tests are illustrated, and the paper demonstrates that estimation using QMLE, allied to a simple bootstrap, yields tests with reliable significance levels and reasonable power, in a majority of cases.

RÉSUMÉ dans des échantillons petits à moyens, il est possible, dans de nombreux cas, de contrôler les niveaux à signification empirique des tests asymptotiques introduits par Kelejian (2008) à l'aide d'un ‘bootstrap’. Dans ce contexte, une caractéristique de l'estimateur GMM, très répandu, est qu'il fournit, dans de petits échantillons, des estimations de paramètres spatiaux situés hors de la région d'inversibilité du modèle. L'emploi de telles estimations illégitimes pour la réalisation d’échantillons ‘bootstrap’ devient alors problématique; la présente communication indique que l'on peut supprimer cet obstacle pratique en utilisant le QMLE garantissant l'inversibilité. Les effets des tendances du poids spatial et la taille des échantillons sur les niveaux d'importance et la puissance sont illustrés, et la communication démontre que le QMLE, allié à un simple ‘bootstrap’, permet de réaliser des tests offrant, dans la plupart des vas, des niveaux d'importance fiables et une puissance raisonnable.

EXTRACTO En muestras entre pequeñas y medianas, los niveles de significancia empírica de las pruebas asintóticas de tipo J para el modelo SARAR introducidas por Kelejian (2008) pueden controlarse en muchos casos mediante el uso de un bootstrap. Una característica del popular estimador GMM dentro de este contexto es que en las muestras pequeñas, a menudo producirá estimaciones de parámetros espaciales que están fuera de la región de reversibilidad del modelo. No obstante, el empleo de este tipo de estimaciones ilegítimas para construir muestras bootstrap es problemático; el estudio actual muestra que este obstáculo práctico puede eliminarse mediante el uso del QMLE que garantiza la reversibilidad. Se ilustran los efectos de las pautas de peso espacial y del tamaño de la muestra sobre el poder y los niveles de significancia, y el estudio demuestra que el QMLE, aliado a un bootstrap simple, dota a las pruebas de niveles de significancia fiables y de un poder razonable, en la mayoría de los casos.

     

Islam in Diaspora: Between Reterritorialization and Extraterritoriality

The concept of ‘diaspora’ seems to be a relevant framework for reading and understanding the parallel strategies of the settled state and mobility in contemporary flows of migration. This article presents a critical overview of the evolution of the concept, and then goes on to hypothesize the long‐term emergence of an Islamic diaspora in Europe, by analysing how Muslims today are reshaping their relations to time and space. The reappropriation of time is articulated on two distinct but complementary levels. The first is expressed through developments in interpretation of the religious sources (ijtihad), demonstrated by a dynamic of conflict in the reterritorialization of the Revelation: the adaptation of Koranic categories to new sets of social issues, individual reappropriation of the Text, the questioning of consistency between belief and normative behaviour by women and young people. The second, more complex level reflects the creation of a form of subjectivity through the development of collective memory and identity. In this, the structuring of a Muslim ‘community’ stumbles against difficulty in accepting the legitimacy of internal pluralism, which is reflected in the struggles between movements and religious leaderships for control of codes of meaning and symbolic boundaries. In contrast, the appropriation of space appears to be broadly under way: this is demonstrated by the successful integration of the majority of Muslims into the local urban space in Europe. This parallel process of settlement and transnational mobility is made possible by the current vitality of the field of religion – a spiritual extraterritoriality that enables fluid, pragmatic management of integration into the European space. Thus, the diaspora is becoming a true social laboratory, in which a flexible category of belonging is developing. La condition diasporique apparait comme une grille de lecture pertinente pour appréhender les stratégies parallèles de sédentarisation et de mobilité des flux migratoires contemporains. Après une synthèse critique de l’évolution du concept, on fait ici l’hypothèse de l’émergence à long terme d’un islam de diaspora en Europe en analysant comment les musulmans y recomposent aujourd’hui leur rapport au temps et à l’espace. La réappropriation du temps s’articule sur deux plans distincts mais complémentaires. Le premier s’exprime à travers l’évolution de l’interprétation des sources religieuses (ijtihad) qui se traduit par une dynamique conflictuelle de re‐territorialisation de la Révélation: adaptation des catégories coraniques aux nouvelles problématiques sociales, réappropriation individuelle du Texte, questionnement des femmes et des jeunes sur la cohérence entre croyance et conduite normative. Le deuxième plus complexe, exprime une subjectivité en marche qui passe par l’élaboration d’une mémoire et d’une identité collective. C’est ainsi que la structuration d’une ‘communauté’ musulmane trébuche encore sur la difficile acceptation de la légitimité d’un pluralisme interne que reflátent les luttes entre mouvements et leadership religieux pour le controle des codes de sens et des frontiáres symboliques. L’appropriation de l’espace apparait par contre largement entamée: en témoigne l’insertion réussie de la majorité des musulmans dans l’espace local urbain européen. Le processus parallále de sédentarisation et de mobilité transnationale est rendue possible grace à l’actuelle vitalité du champ religieux, extra‐territorialité spirituelle, qui permet ainsi une gestion fluide et pragmatique de l’insertion dans l’espace européen. La diaspora devient alors un véritable laboratoire social où s’élabore une catégorie flexible de l’appartenance.     

Blocked-Error-R 2: A Conceptually Improved Definition of the Proportion of Explained Variance in Models Containing Loops or Correlated Residuals

Bentler and Raykov (2000, Journal of Applied Psychology 85: 125–131), and Jöreskog (1999a, http://www.ssicentral.com/lisrel/column3.htm, 1999b http://www.ssicentral. com/lisrel/column5.htm) proposed procedures for calculating R ² for dependent variables involved in loops or possessing correlated errors. This article demonstrates that Bentler and Raykov’s procedure can not be routinely interpreted as a “proportion” of explained variance, while Jöreskog’s reduced-form calculation is unnecessarily restrictive. The new blocked-error-R ² (beR ²) uses a minimal hypothetical causal intervention to resolve the variance-partitioning ambiguities created by loops and correlated errors. Hayduk (1996) discussed how stabilising feedback models – models capable of counteracting external perturbations – can result in an acceptable error variance which exceeds the variance of the dependent variable to which that error is attached. For variables included within loops, whether stabilising or not, beR ² provides the same value as Hayduk’s (1996) loop-adjusted-R ². For variables not involved in loops and not displaying correlated residuals, beR ² reports the same value as the traditional regression R ². Thus, beR ² provides a conceptualisation of the proportion of explained variance that spans both recursive and nonrecursive structural equation models. A procedure for calculating beR ² in any SEM program is provided.     

Agglomeration,Agriculture, and the Perspective of the Periphery

Abstract

This paper aims at pulling everything related to ‘agriculture’ or the ‘periphery’ a little more into the focus of research. We try to achieve this through surveying the existing theoretical and empirical literature in the field of NEG (New Economic Geography) in order to elaborate its linkages to immobile factors such as land, land-intensive productive activities, agriculture, rural areas, and the periphery. The main features of the broad variety of NEG models are reviewed with a special focus on the theme of agglomeration, which turns out to be vital for rural areas. All of these contributions are then commented on, with the aim of suggesting and discussing some future lines of research in the field.

Agglomération, agriculture, et la perspective de la périphérie

RÉSUMÉ La présente communication s'efforce de placer davantage tout ce qui concerne ‘l'agriculture’ ou la ‘périphérie’ sous l'optique de la recherche. Pour ceci, nous nous efforçons d'examiner de près les ouvrages théoriques et empiriques existants dans le domaine du NEG (New Economic Geography), afin d'en examiner les rapports avec des facteurs immuables comme la terre, les activités de production à utilisation intensive de la terre, l'agriculture, les zones rurales, et la périphérie. On se penche sur les principales caractéristiques du grand nombre de modèles NEG, en mettant tout particulièrement l'accent sur le thème de l'agglomération, qui s'avère jouer un rôle d'importance primordiale pour les zones rurales. On présente ensuite des commentaires sur toutes ces contributions dans le but de proposer certaines filières de recherche futures dans ce domaine, et d'en discuter.

Aglomeración, agricultura y la perspectiva de la periferia

RÉSUMÉ Este trabajo tiene como objetivo poner todo lo relacionado con la ‘agricultura’ o la ‘periferia’ un poco más en el foco de investigación. Intentamos hacerlo a través de una inspección de la bibliografía teórica y empírica existente en el campo NEG (New Economic Geography), con objeto de elaborar sus vínculos con factores inmóviles, tales como el terreno, actividades productivas que requieren terreno, agricultura, áreas rurales y la periferia. Las principales características de la amplia variedad de modelos NEG se revisan con un enfoque especial en el tema de la aglomeración, que resulta tener una importancia vital para las áreas rurales. Seguidamente, todas estas contribuciones se comentan con el propósito de sugerir y discutir líneas futuras de investigación en el campo.

     

A copula-based time series model for global horizontal irradiation

The increasing importance of solar power for electricity generation leads to increasing demand for probabilistic forecasting of local and aggregated photovoltaic (PV) yields. Based on publicly available irradiation data, this paper uses an indirect modeling approach for hourly medium to long-term local PV yields. We suggest a time series model for global horizontal irradiation that allows for multivariate probabilistic forecasts for arbitrary time horizons. It features several important stylized facts. Sharp time-dependent lower and upper bounds of global horizontal irradiations are estimated. The parameters of the beta distributed marginals of the transformed data are allowed to be time-dependent. A copula-based time series model is introduced for the hourly and daily dependence structure based on simple vine copulas with so-called tail dependence. Evaluation methods based on scoring rules are used to compare the model’s power for multivariate probabilistic forecasting with other models used in the literature showing that our model outperforms other models in many respects.     

A Bayesian analysis of suicide data

The identification of change points in a sequence of suicide rates is one of the fundamental aspects of Durkheim’s theory. The specification of a statistical standard suitable for this purpose is the main condition for making inferences about the causes of suicide with distinctive trends of persistency and variability just as Durkheim theorized. At present, the statistical ‘strategy’ employed by the French social scientist is too ‘rudimentary’. A hundred years later, I take the opportunity to test Durkheim’s theory through modern methodological instruments, specifically the Bayesian change-point analysis. First of all, I analyzed the same suicide data which Durkheim took into consideration. Change-point analysis corroborates the Durkheimian analysis revealing the same change-points identified by the author. Secondly, I analyzed Italian suicide rates from 1864 to 2005. The change-point analysis was very useful. Durkheim’s theory ‘works’ until 1961: suicides rates increased as industrial development increased. However, after 1961 and the economic boom, they declined, and when they began increasing again, after 1984, they did not reach the same level as before. This finding obliges us to ‘adjust’ the Durkheim’s theory giving space to Halbwach’s convergence law. Therefore, as high economic and social development levels are attained, suicide rates tend to level-off: People adapt to the stress of modernization associated to low social integration levels. Although we are more ‘egoist’, individualism does not destroy identity and the sense of life as Durkheim had maintained.     

Applied Spatial Econometrics: Raising the Bar

Abstract

This paper places the key issues and implications of the new ‘introductory’ book on spatial econometrics by James LeSage & Kelley Pace (2009) in a broader perspective: the argument in favour of the spatial Durbin model, the use of indirect effects as a more valid basis for testing whether spatial spillovers are significant, the use of Bayesian posterior model probabilities to determine which spatial weights matrix best describes the data, and the book's contribution to the literature on spatio-temporal models. The main conclusion is that the state of the art of applied spatial econometrics has taken a step change with the publication of this book.

Relever le niveau de l'économetrie spatial appliquée

RÉSUMÉ La présente communication place les principales questions et implications du nouvel ouvrage d'introduction sur l'économétries spatiale de James LeSage & Kelley Pace (2009) dans un contexte plus général: l'argument favorisant le modèle spatial de Durbin, l'emploi d'effets indirects comme base plus valable pour évaluer l'aspect significatif des déversements spatiaux, l'emploi des probabilités d'un modèle baysien postérieur pour évaluer laquelle des matrices de poids spatiaux décrit le mieux les donnes, et la contribution de l'ouvrage la documentation sur les modèles spatio-temporels. La principale conclusion est qu'avec la publication de cet ouvrage, l'état de l'art de l'économétries spatiale applique a effectué un grand pas en avant.

Alzar el nivel de la econometría espacial aplicada

RÉSUMÉ Este trabajo plantea las cuestiones e implicaciones clave del nuevo libro introductorio sobre económetra espacial de James LeSage & Kelley Pace (2009) dentro de una perspectiva más amplia: el argumento a favor del modelo espacial Durbin, el uso de efectos indirectos como una base más válida para poner a prueba si los desbordamientos espaciales son significativos, el uso de probabilidades posteriores bayesianas para descubrir que matriz de pesos espaciales describe mejor los datos, y la contribución del libro a la bibliógrafa sobre modelos espaciotemporales. La principal conclusión es que la econometría espacial aplicada más avanzada ha experimentado un cambio radical con la publicación de este libro.

     

A Study of Vertical Integration and Vertical Divestiture: The Case of Store Brand Milk Sourcing in Boston

This article investigates whether a retailer’s store brand supply source impacts vertical pricing and supply channel profitability. Using chain‐level retail scanner data, a random coefficients logit demand model is estimated employing a Bayesian estimation approach. Supply models are specified conditional on demand parameter estimates. Bayesian decision theory is applied to select the best fitting pricing model. Results indicate that a vertically integrated retailer engages in linear pricing for brand manufacturers’ products while competing retailers make nonlinear pricing contracts with brand manufacturers for branded products and store brands. A simulated vertical divestiture based on real world events provides evidence for improved channel efficiency.     

Expatriate management and national culture: a bibliometric study of prolific,productive, and most cited authors and institutions

Abstract

This is a bibliometric study of reference literature related to the influence of national culture issues on expatriate management. It is based on publications in elite Management, International Business, and Human Resource academic journals between 2000 and 2012. The database comprises 222 articles involving 368 authors and 223 academic institutions. The analysis uses a broad scoring procedure that includes: (I) scholars and institutions’ productivity in terms of number of publications (both, total and adjusted), (II) authors and institutions’ productivity in terms of potential impact based on journals’ performance (a wide spectrum of different metrics is used in order to allow for alternative perspectives), and (III) a citation analysis. The use of multiple and diverse scores provides a comprehensive understanding of the ranking of academic institutions and scholars within this particular subfield of research. In addition, the article analyzes collaborative research patterns, expected institutional influence in the near future, and main issues to be included in the field’s research agenda.     

Procedures and Consistency Versus Flexibility and Commitment In Employee Relations: A Comment On Storey

Jon Clark, who is Professor of Industrial Relations at Southampton University, comments on one of the most important issues raised in John Storey's Developments in the Management of Human Resources: the contrast between the ‘procedure and consistency’ of the IR/ personnel tradition and the ‘business need, flexibility and commitment’ of the HRM tradition. In particular, he queries whether HRM can be successful without a firm basis in ‘procedure and consistency’.     

The Reassertion of Economics: 1990s Gentrification in the Lower East Side

This article utilizes property tax arrears data to trace the contraction of gentrification at the end of the 1980s and its resurgence in the 1990s in New York City’s Lower East Side. Contrary to the claims made during the recession about the end of gentrification, this article provides an important historical record of the resurgence of gentrification in the 1990s. The paper also argues that this new ‘third round’ gentrification has to be seen as a dramatic reassertion of economics in the central urban land market. That this shift is also expressed within the popular cultural discourses accompanying the process reveals an altered relationship between economics and culture in fin de siècle gentrification. Cet article utilise les données sur les arriérés des impôts sur la propriété pour retracer le déclin de l’embourgeoisement á la fin des années quatre-vingt et son renouveau dans les années quatre-vingt-dix dans le Lower East Side de New York City. Contrairement á ce qui fut dit sur la fin de l’embourgeoisement durant la récession, cet article fournit un dossier historique important qui montre le renouveau de l’embourgeoisement dans les années quatre-vingt-dix. Cet article soutient aussi que ce nouveau ‘troisième tour’ d’embourgeoisement doit ? tre regardé comme une réaffirmation dramatique de l’économie politique dans le marché foncier urbain central. Le fait que ce changement est aussi perceptible dans les discours de la culture populaire qui accompagnent ce processus révèle une relation changée entre l’écomonie politique et la culture dans l’embourgeoisement de fin de siècle.     

Interregional Inequality Dynamics in Mexico

Abstract

This paper examines 60 years of regional income inequality dynamics across the states of Mexico. Drawing on recent developments in exploratory spatial data analysis (ESDA) we examine the role of spatial clustering and heterogeneity in the evolution of regional inequality. We pay particular attention to the choice of the regionalization scheme that has been applied in previous work and we suggest a number of new approaches to evaluate the sensitivity of inferential conclusions to this choice. We also investigate if temporal shifts in equality are reflected in the NAFTA era.

Dynamique de l'inégalité interrégionale au Mexique

Résumé la présente communication se penche sur la dynamique des inégalités régionales entre les revenus pendant 60 ans dans les états du Mexique. Sur la base de développements récents dans les analyses exploratoires des données spatiales (ESDA), nous examinons le rôle du groupage et de l'hétérogénéité spatiaux dans l’évolution des inégalités régionales, en nous penchant tout particulièrement sur le choix du plan de régionalisation appliqué à des travaux précédents, et en proposant un certain nombre de méthodes nouvelles pour évaluer la sensibilité de conclusions déductives sur ce choix. En outre, nous tentons d’établir si des changements temporels dans les inégalités sont reflétés dans l’ère de NAFTA.

Dinámica de la desigualdad interregional en Méjico

Extracto Este trabajo examina 60 años en la dinámica de la desigualdad regional de ingresos a través de los estados de Méjico. Haciendo uso de desarrollos recientes en el análisis exploratorio de datos espaciales (ESDA) examinamos la función del agrupamiento espacial y la heterogeneidad en la evolución de la desigualad regional. Prestamos particular atención a la elección del esquema de regionalización que se ha aplicado en trabajo anterior y sugerimos varios planteamientos nuevos para evaluar la sensibilidad de conclusiones inferenciales de esta elección. También investigamos si los cambios temporales en igualdad se reflejan en la era NAFTA (Tratado de Libre Comercio de América del Norte).

     

The diffusion of mobile social networking: Further study

In a recent study, Scaglione et al. (2015) analyzed the diffusion of mobile social networking in four G7 countries. Using Bass’s model and Bemmaor’s Gamma/Shifted Gompertz (G/SG) model, they found evidence of a left skew in the right-censored distributions of the times to adoption in three countries out of four. However, this conclusion relied on the skewness parameter of Bemmaor’s model. We reanalyze the data, making use of three special cases of the G/SG as well as the full version. Extending the data set to six countries, we show that (i) fitting the four models to the data does not allow us to discriminate between models, but (ii) forecasting the subsequent adoptions provides a strong support of right skewness in the data set: each country (except France) shows a substantial mass of later adopters of mobile social networking following an initial embrace of the access.     

Global team members’ performance and the roles of cross-cultural training,cultural intelligence,and contact intensity: the case of global teams in IT offshoring sector

Abstract

This study investigates an unexplored form of global team prevalent in the Information Technology (IT) offshoring sector where IT service providers work alongside with client representatives in a global team context. Guided by theories of intelligence and intergroup contact, this study investigates global team members’ individual-level task performance. Specifically, this study examines the development of global team members’ cultural intelligence (CQ) following cross-cultural training. This study also determines the effects of improved CQ on individual-level task performance and examines the moderating role of contact intensity on the relationship between improved CQ and individual-level task performance. Data on the development of CQ, participation in cross-cultural training, and contact intensity were collected from 225 global team members while data on task performance were obtained from each of the global team members’ supervisors. The results of the statistical analyses reveal that: (i) CQ improved following participation in cross-cultural training sessions; (ii) improved CQ is positively and significantly related to individual-level task performance; and (iii) contact intensity moderates the relationship between improved CQ and individual-level task performance. These findings have a number of theoretical and practical implications for international organizations such as those in the IT offshoring sector.     

The Relationship of Housing Prices and Transportation Improvements: Location and Marginal Impact

Abstract

In this paper, I examine the relationship between housing prices and transport improvements. The relationship between distance and housing prices is known to be negative for a densely populated area. I will examine whether this relationship holds for a sparsely populated area, and will test whether this relationship is convex with respect to distance. A macro panel dataset from Iceland will be used. The existence of the expected relationship is among the main findings. Thus, transportation improvements between the CBD and other localities have greater marginal impact on the local real price of houses in closer localities compared to those which are farther away.

Rapports marginaux entre prix de l'immobilier et améliorations dans les transports: emplacement et impact marginal

Résumé Dans la présente communication, j'examine le rapport entre le prix de l'immobilier et l'amélioration des transports. On sait que le rapport entre la distance et le prix de l'immobilier est négatif pour les zones à forte densité de population. Je vais examiner si ce rapport reste vrai pour des zones à faible densité, et effectuer des essais afin d’établir si ce rapport est convexe en fonction de la distance. Un ensemble de données de macro panel provenant d'Islande sera utilisé. Une des principales conclusions est l'existence de rapports prévus. Ainsi, les améliorations des transports entre CBD et d'autres lieux ont un impact marginal supérieur sur le prix réel local de l'immobilier dans des localités plus proches, par rapport à des localités plus éloignées.

La relación marginal de los precios de la vivienda y las mejoras del transporte: ubicación e impacto marginal

Extracto En este trabajo examino la relación entre los precios de la vivienda y las mejoras en el transporte. Se sabe que la relación entre la distancia y los precios de la vivienda es negativa en las áreas densamente pobladas. Examinaré si esta relación se mantiene en un área escasamente poblada, y ensayaré si es convexa con respecto a la distancia. Se utilizará un conjunto de datos de macro-panel procedente de Islandia. La existencia de la relación esperada es uno de los principales descubrimientos. Así, las mejoras del transporte entre el CBD (distrito central de negocios) y otras localidades tienen un mayor impacto marginal sobre el precio local real de la vivienda en localidades más próximas, en comparación con las que están más alejadas.

     

ANOTHER LOOK AT ‘BANK COMPETITION AND FINANCIAL STABILITY: MUCH ADO ABOUT NOTHING’?

This study replicates Zigraiova and Havranek's (2016) meta-analysis of banking competition and financial stability. It performs multiple types of replications: a ‘Reproduction’ replication where Z&H's data and code are verified to reproduce the results of their study; a ‘Repetition’ replication where the studies used by Z&H are independently recoded and then re-analysed; an ‘Extension’ replication where additional studies on banking competition and stability are analysed; and a ‘Robustness Analysis’ where we check Z&H's results using an alternative empirical procedure. Our analysis strongly confirms Z&H's main finding that competition in the banking sector has an economically negligible effect on financial stability. This result is consistently confirmed across a variety of replication analyses. Most impressively, we confirm their finding even when we analyse a completely independent set of 35 studies not included in Z&H's meta-analysis. Our results for Z&H's other findings are less supportive. As the first comprehensive replication of a meta-analysis, this study also provides insights into the robustness of meta-analysis. We find that meta-regression analysis, where estimated effects are related to data, estimation, and study characteristics, is sensitive to how data are coded and to the choice of estimation procedure; and that this sensitivity extends to ‘best practice’ estimates.     

2.25Cr-1Mo-0.25V钢焊接工艺研究

本文通过一系列试验研究Cr-Mo钢中的新型钢2.25Cr-1Mo-0.25V钢的性能、焊接工艺、热处理等等。试验中采用法国SAF公司提供的焊丝S225V和焊剂F537,采用埋弧焊焊接方法,并经焊后热处理后,进行了化学成分分拉伸试验,AKV冲击等试验,试验结果均符合要求,试验表明:通过对2.25Cr-1Mo-0.25V钢性能的了解,确定了选择焊接材料的方法,选定焊丝S225V和焊剂F537,并制定了合理的焊接工艺;确定2.25Cr-1Mo-0.25V钢理想预热温度为180℃;确定焊后热处理温度,并且通过各项实验证明焊后热处理温度的合理性。