Job Opportunities, Amenities, and Variable Distance-Deterrence Elasticities: An Empirical Model of Inter-Municipal Migration in Belgium

This paper investigates inter-municipal migration flows in Belgium using a Poisson gravity model. Besides distance, the model also includes municipal-specific factors as explanatory variables. The model is tested using aggregate, cross-sectional, data on migrations between the municipalities of the Belgian province of Limburg, over the period 1998-2003. The model assumes heterogeneity of the distance-deterrence effect. The model also accounts for unobserved origin/destination characteristics. To overcome the problem of under-determinacy, we use the method of Generalized Cross-Entropy estimation. A number of major findings stand out. Firstly, we find evidence of a "U-shaped" relationship between the distance-deterrence elasticity and distance, where the distance elasticity is smaller for short-distance moves. Secondly, distance between origin and destination reinforces (attenuates) the pull effect of local employment opportunities (amenities). This finding may indicating a shift in the composition of migration flows from residential migration to labor migration as distance increases. Finally, the spatial distribution of the net pull effects of unobserved factors seem to coincide with proximity to major roads and railway stations.

Local law-of-the-wall in complex topography: a confirmation from wind tunnel experiments

It is well known that in a neutrally-stratified turbulent flow in a deep constant-stress layer above a flat surface, the variation of the mean velocity with respect to the distance from the surface obeys the logarithmic law (the so-called ``law-of-the-wall''). More recently, the same logarithmic law has been found also in the presence of non flat surfaces. It governs the dynamics of the mean velocity (i.e. all the smaller scales are averaged out) and involves renormalized effective parameters. Recent numerical simulations analyzed by the authors of the present Letter show that a more intrinsic logarithmic shape actually takes place also at smaller scales. Such a generalized law-of-the-wall involves effective parameters smoothly depending on the position along the underlying topography. Here, we present wind tunnel experimental evidence confirming and corroborating this new-found property. New results and their physical interpretation are also presented and discussed.Comment: 9 pages, (Latex), 4 figure

A distance measure of interval-valued belief structures

Interval-valued belief structures are generalized from belief function theory, in terms of basic belief assignments from crisp to interval numbers. The distance measure has long been an essential tool in belief function theory, such as conflict evidence combinations, clustering analysis, belief function and approximation. Researchers have paid much attention and proposed many kinds of distance measures. However, few works have addressed distance measures of interval-valued belief structures up. In this paper, we propose a method to measure the distance of interval belief functions. The method is based on an interval-valued one-dimensional Hausdorff distance and Jaccard similarity coefficient. We show and prove its properties of non-negativity, non-degeneracy, symmetry and triangle inequality. Numerical examples illustrate the validity of the proposed distance

Horizontal versus Vertical Interdependence in Multinational Activity

Recent research in international economics highlights the role of interdependencies of investment decisions and sales of multinational firms. Previous work focused on and provided evidence for aggregate flows or stocks of foreign direct investment, showing that interdependence declines in geographical distance among host countries. This could be interpreted as implicit evidence for export-platform foreign direct investment—an activity which creates a complementary relationship between (potential) host markets through final goods exports of foreign subsidiaries to third countries. This paper sheds light on interdependencies that are brought about by (horizontal) trade in final goods and (vertical) trade in intermediate goods (within and between host countries). For this, we use a panel data set of U.S. foreign affiliate sales to 16 developed countries in 7 industries over the period 1983-2000. As one of the first studies on that matter, we explicitly distinguish between horizontal and vertical interdependence in MNE activity and allow for both market size (demand) related as well as remainder linkage effects. The latter are captured by a second order spatial regressive error process. Overall, there is evidence for mainly vertical as opposed to horizontal interdependence and, hence, mainly vertical motives of multinational activity.multinational firms, foreign affiliate sales, spatial econometrics, generalized method of moments estimation, panel data analysis

Institutions, geography, trade, and income per capita: A spatial-simultaneous equation approach

This paper tests a series of prominent hypotheses regarding how institutions, geography, and trade interact to influence income per capita using a novel spatial econometric approach to control for both spillovers among neighboring countries and spatially correlated omitted variables. Simultaneous equations are used to identify alternative channels through which country characteristics might affect income through trade and institutions, and then to test the robustness of those effects. Evidence indicated that both institutions and trade influence growth. Geographical factors such as whether a country is landlocked and its distance to the equator influence income, but only through trade. Data covering 95 countries across the world from 1960 through 2002 was used to construct a pooled dataset of 5-year averages (9 in all) centered on 1960, 1965, and so on through 2000. Both limited and full information estimators, partly based on a generalized moments (GM) estimator for spatial autoregressive coefficients, were used. These allow for spatial error correlation, correlation across equations, and the presence of spatially lagged dependent variables.economic growth, Geography, Institutions, simultaneous equations, spatial econometrics, trade,