The World Trade Web: A Multiple-Network Perspective

International Trade (IT) plays a fundamental role in today's economy: by connecting world countries production and consumption processes, it radically contributes in shaping their economy and development path. Although its evolving structure and determinants have been widely analyzed in the literature, much less has been done to understand its interplay with other complex phenomena. The aim of this work is, precisely in this direction, to study the relations of IT with International Migration (IM) and Foreign Direct Investments (FDI). In both cases the procedure used is to first approach the problem in a multiple-networks perspective and than deepen the analysis by using ad hoc econometrics techniques. With respect to IM, a general positive correlation with IT is highlighted and product categories for which this effect is stronger are identified and cross-checked with previous classifications. Next, employing spatial econometric techniques and proposing a new way to define country neighbors based on the most intense IM flows, direct/indirect network effects are studied and a stronger competitive effect of third country migrants is identified for a specific product class. In the case of FDI, first correlations between the two networks are identified, highlighting how they can be mostly explained by countries economic/demographic size and geographical distance. Then, using the Heckman selection model with a gravity equation, (non-linear) components arising from distance, position in the Global Supply Chain and presence of Regional Trade Agreements are studied. Finally, it is shown how IT and FDI correlation changes with sectors: they are complements in manufacturing, but substitutes in services.Comment: PhD thesis at IMT Institute for Advanced Studies Lucca. 114 pages, 12 figures, 18 table

Visualisation of Origins, Destinations and Flows with OD Maps

We present a new technique for the visual exploration of origins (O) and destinations (D) arranged in geographic space. Previous attempts to map the flows between origins and destinations have suffered from problems of occlusion usually requiring some form of generalisation, such as aggregation or flow density estimation before they can be visualized. This can lead to loss of detail or the introduction of arbitrary artefacts in the visual representation. Here, we propose mapping OD vectors as cells rather than lines, comparable with the process of constructing OD matrices, but unlike the OD matrix, we preserve the spatial layout of all origin and destination locations by constructing a gridded two‐level spatial treemap. The result is a set of spatially ordered small multiples upon which any arbitrary geographic data may be projected. Using a hash grid spatial data structure, we explore the characteristics of the technique through a software prototype that allows interactive query and visualisation of 105‐106 simulated and recorded OD vectors. The technique is illustrated using US county to county migration and commuting statistics

Spatial Unemployment Differentials in Colombia

This paper studies the geographic distribution of unemployment rates in Colombian urban areas. It introduces measures of spatial correlation and spatial econometric techniques to analyze the dependence in local unemployment rates across municipalities. Results suggest that Colombian municipalities have experienced a polarization process between 1993 and 2005, as municipalities' unemployment rates have followed different evolutions relative to the National average. This process has been accompanied by the creation of unemployment clusters, that is to say, municipalities had very similar unemployment outcomes to those of their neighbors. This analysis uses a spatial Durbin model to explore the influence of various factors in determining differences in regional unemployment rates. According to our findings differences in labor demand, immigration rates, and urbanization are factors behind observed municipal unemployment disparities.local labor markets, unemployment di erential, polarization, clustering, spatial econometrics, spatial Durbin model

Chow-Lin Methods in Spatial Mixed Models

Missing data in dynamic panel models occur quite often since detailed recording of the dependent variable is often not possible at all observation points in time and space. In this paper we develop classical and Bayesian methods to complete missing data in panel models. The Chow-Lin (1971) method is a classical method for completing dependent disaggregated data and is successfully applied in economics to disaggregate aggregated time series. We will extend the space-time panel model in a new way to include cross-sectional and spatially correlated data. The missing disaggregated data will be obtained either by point prediction or by a numerical (posterior) predictive density. Furthermore, we point out that the approach can be extended to more complex models, like ow data or systems of panel data. The panel Chow-Lin approach will be demonstrated with examples involving regional growth for Spanish regions.Space-time interpolation, Spatial panel econometrics, MCMC, Spatial Chow-Lin, missing regional data, Spanish provinces, MCMC, NUTS: nomenclature of territorial units for statistics

The migration network effect on international trade

This paper studies the relationship between migration and trade, with the aim of measuring both direct and indirect network effects. We analyze trade of diferentiated and homogeneous goods using an econometric approach inspired by spatial econometrics, proposing a new way to define country neighbors based on the most intense links in the migration network. We find that migration significantly affects trade across categories both in direct and in indirect way. The indirect impact highlights a stronger competitive effect of third country migrants for homogeneous goods. We also confirm that the effect of migration channels is higher on differentiated goods

Community-driven dispersal in an individual-based predator-prey model

We present a spatial, individual-based predator-prey model in which dispersal is dependent on the local community. We determine species suitability to the biotic conditions of their local environment through a time and space varying fitness measure. Dispersal of individuals to nearby communities occurs whenever their fitness falls below a predefined tolerance threshold. The spatiotemporal dynamics of the model is described in terms of this threshold. We compare this dynamics with the one obtained through density-independent dispersal and find marked differences. In the community-driven scenario, the spatial correlations in the population density do not vary in a linear fashion as we increase the tolerance threshold. Instead we find the system to cross different dynamical regimes as the threshold is raised. Spatial patterns evolve from disordered, to scale-free complex patterns, to finally becoming well-organized domains. This model therefore predicts that natural populations, the dispersal strategies of which are likely to be influenced by their local environment, might be subject to complex spatiotemporal dynamics.Comment: 43 pages, 7 figures, vocabulary modifications, discussion expanded, references added, Ecological Complexity accepte

An alternative framework for studying the effects of family policies on fertility in the absence of individual-level data: a spatial analysis with small-scale macro data on Germany

For studying both individual-level and small-scale contextual influences on the effects of family policies on fertility, Multilevel Event History methods are the state-of-the-art. But in many countries, these methods cannot be applied because the available individual-level data are inadequate. This paper uses an alternative methodological framework that can be of help in these cases. It utilizes small-scale macro data, which is analyzed with Exploratory Data, Cluster, and Spatial Panel Model Analysis techniques. In a case study on the western German city of Bremen, the potential of this approach, as well as its limitations, are investigated. The study analyzes the impact of the parental leave reform of 1986 and the child benefit reform of 1996 on fertility levels in different city quarters (Stadtteile) of Bremen. The results indicate that both family policy reforms had, at least in the short-term, a significant impact on fertility levels. These positive effects were stronger in economically disadvantaged quarters. The findings also suggest that the reforms affected the timing more than the quantum of fertility. With regard to the methodological framework, we can conclude that the Spatial Analysis with small-scale macro data is a useful alternative when there is no individual-level data available for carrying out a Multilevel Event History Analysis.Bremen, Germany, family policies, fertility trends, methodology, spatial analysis

Quality of life in the regions: An exploratory spatial data analysis for West German labor markets

Which of Germanys regions is the most attractive? Where is it best to live and work - on objective grounds? These questions are summed up in the concept quality of life. This paper uses recent research projects that determine this parameter to examine the spatial distribution of quality of life in Germany. For this purpose, an Exploratory Spatial Data Analysis is conducted which focuses on identifying statistically significant (dis-)similarities in space. An initial result of this research is that it is important to choose the aggregation level of administrative units carefully when considering a spatial analysis. The level plays a crucial role in the strength and impact of spatial effects. In concentrating on various labor market areas, this paper identifies a significant spatial autocorrelation in the quality of life, which seems to be characterized by a North-Mid-South divide. In addition, the ESDA results are used to augment the regression specifications, which helps to avoid the occurrence of spatial dependencies in the residuals. --Quality of Life,Exploratory Spatial Data Analysis,Functional Economic Areas,Spatial Econometrics,LISA Dummies

Trading Cultural Goods in the Era of Digital Piracy

The issue of digital piracy as violation of intellectual property rights is a hot button among many governments around the world. Until now, nor legislation or its enforcement have managed to keep up with the most recent technologies facilitating piracy. Piracy rates may significantly affect both internal demand and international trade of cultural goods. This paper aims to empirically assess the effect of digital piracy on bilateral trade in cultural goods. We focus on trade in music and media. Analysing an 11-year panel of 25 countries, we find that piracy does affect negatively bilateral trade, although to a varying extent.trade; cultural goods; piracy; spatial filtering; network autocorrelation