Industrial districts, innovation and I-district

The I-district effect hypothesis establishes the existence of highly intense innovation in Marshallian industrial districts due to the presence of external localization economies. However, industrial districts are characterized by specific manufacturing specializations in such a way that this effect could be due to these dominant specializations. The objective of this research is to test whether the effect is explained by the conditions of the territory or by the industrial specialization and to provide additional evidence of the existence and causes of the highly intense innovation in industrial districts (I-district effect). The estimates for Spain of a fixed effects model interacting territory and industry suggest that the high innovative performance of industrial districts is maintained across sectors whereas the industrial specialization behaves differently depending on the type of local production system in which it is placed. The I-district effect is related to the conditions of the territory more than to the industrial specialization. The territory is a key variable in explaining the processes of innovation and should be considered a basic dimension in the design of innovation and industrial policies.

Surface collective oscillations of metal clusters and spheres: Random-phase-approximation sum-rules approach

Using the once and thrice energy-weighted moments of the random-phase-approximation strength function, we have derived compact expressions for the average energy of surface collective oscillations of clusters and spheres of metal atoms. The L=0 volume mode has also been studied. We have carried out quantal and semiclassical calculations for Na and Ag systems in the spherical-jellium approximation. We present a rather thorough discussion of surface diffuseness and quantal size effects on the resonance energies.

Critical clusters and efficient dynamics for frustrated spin models

A general method to find, in a systematic way, efficient Monte Carlo cluster dynamics among the avast class of dynamics introduced by Kandel et al. [Phys. Rev. Lett. 65, 941 (1990)] is proposed. The method is successfully applied to a class of frustrated two-dimensional Ising systems. In the case of the fully frustrated model, we also find the intriguing result that critical clusters consist of self-avoiding walk at the theta point.

Urban space and industrial heritage

Postprint (published version)

The impact of FTAs on MENA trade in agricultural and industrial products

This paper analyses the impact of Free Trade Agreements (FTAs) on Middle East and North African Countries (MENA) trade for the period 1994-2010. The analysis distinguishes between industrial and agricultural trade to take into account the different liberalisation schedules. An augmented gravity model is estimated using up-to-date panel data techniques to control for all time-invariant bilateral factors that influence bilateral trade as well as for the so-called multilateral resistance factors. We also control for the endogeneity of the agreements and test for self-selection bias due to the presence of zero trade in our sample. The main findings indicate that North-South-FTAs and South-South- FTAs have a differential impact in terms of increasing trade in MENA countries, with the former being more beneficial in terms of exports for MENA countries, but both showing greater global market integration. We also find that FTAs that include agricultural products, in which MENA countries have a clear comparative advantage, have more favourable effects for these countries than those only including industrial products. JEL code: F10, F15

Industrial district effects and innovation in the Tuscan shipbuilding industry

The aim of the present work is to investigate innovative processes within a geographical cluster, and thus contribute to the debate on the effects of industrial clusters on innovation capacity. In particular, we would like to ascertain whether the advantages of industrial districts in promoting innovation, as already revealed by literature (diffusion of knowledge, social capital and trust, efficient networking), are also keys to success in the Tuscan shipbuilding industry of pleasure and sporting boats. First, we verify the existence of clusters of shipbuilding in Tuscany, using a specific methodology. Next, in the identified clusters, we analyse three innovative networks financed in a policy to support innovation, and examine whether the typical features of a cluster for promoting innovation are at work, using a questionnaire administered to 71 actors. Finally, we develop a performance analysis of the cluster firms and ascertain whether their different behaviours also lead to different performances. The analysis results show that our case records effects of industrial clustering on innovation capacity, such as the important role given to trust and social capital, the significant worth put in interfirm relations and in each partner’s specific competencies, or even the distinctive performance of firms belonging to a cluster.

Giacomo Becattini and the Marshall's method. A Schumpeterian approach

The studies of Giacomo Becattini concerning the notion of the "Marshallian industrial district" have led a revolution in the field of economic development around the world. The paper offers an interpretation of the methodology adopted by Becattini. The roots are clearly Marshallian. Becattini proposes a return to the economy as a complex social science that operates in historical time. We adopt a Schumpeterian approach to the method in economic analysis in order to highlight the similarities between the Marshall and Becattini's approach. Finally the paper uses the distinction between logical time, real time and historical time which enable us to study the "localized" economic process in a Becattinian way.

Industrial agglomerations and wage gradients: the Spanish economy in the interwar period

This paper gives new evidence on the relationship between integration and industrial agglomeration in the presence of scale economies, by testing directly one of the predictions that can be derived from Krugman (1991), that is, the existence of regional nominal wage gradients and its transformation following changes in trade regimes. Our case study analyzes the effects of the substitution of an open economy by a closed economy regime, exactly the opposite process studied by Hanson (1996, 1997). In Spain, during the interwar period, protectionist policies would have favored the loss of centrality of the coastal location (Barcelona) and the relative rise of central locations (such as Madrid). Our results indicate the existence of a wage gradient centered in Barcelona during the interwar period (1914-1930) and its weakening after 1925.

Industrial agglomerations and wage gradients: the Spanish economy in the interwar period

This paper gives new evidence on the relationship between integration and industrial agglomeration in the presence of scale economies, by testing directly one of the predictions that can be derived from Krugman (1991), that is, the existence of regional nominal wage gradients and its transformation following changes in trade regimes. Our case study analyzes the effects of the substitution of an open economy by a closed economy regime, exactly the opposite process studied by Hanson (1996, 1997). In Spain, during the interwar period, protectionist policies would have favored the loss of centrality of the coastal location (Barcelona) and the relative rise of central locations (such as Madrid). Our results indicate the existence of a wage gradient centered in Barcelona during the interwar period (1914-1930) and its weakening after 1925.

Spatial correlations and cross sections of clusters in the A + B -> 0 reaction

We consider the distribution of cross sections of clusters and the density-density correlation functions for the A+B¿0 reaction. We solve the reaction-diffusion equations numerically for random initial distributions of reactants. When both reactant species have the same diffusion coefficients the distribution of cross sections and the correlation functions scale with the diffusion length and obey superuniversal laws (independent of dimension). For different diffusion coefficients the correlation functions still scale, but the scaling functions depend on the dimension and on the diffusion coefficients. Furthermore, we display explicitly the peculiarities of the cluster-size distribution in one dimension.

Genesis and evolution of the Evx and Mox genes and the extended Hox and ParaHox gene clusters

Background: Hox and ParaHox gene clusters are thought to have resulted from the duplication of a ProtoHox gene cluster early in metazoan evolution. However, the origin and evolution of the other genes belonging to the extended Hox group of homeobox-containing genes, that is, Mox and Evx, remains obscure. We constructed phylogenetic trees with mouse, amphioxus and Drosophila extended Hox and other related Antennapedia-type homeobox gene sequences and analyzed the linkage data available for such genes.Results: We claim that neither Mox nor Evx is a Hox or ParaHox gene. We propose a scenariothat reconciles phylogeny with linkage data, in which an Evx/Mox ancestor gene linked to aProtoHox cluster was involved in a segmental tandem duplication event that generated an arrayof all Hox-like genes, referred to as the `coupled¿ cluster. A chromosomal breakage within thiscluster explains the current composition of the extended Hox cluster (with Evx, Hox and Moxgenes) and the ParaHox cluster.Conclusions: Most studies dealing with the origin and evolution of Hox and ParaHox clustershave not included the Hox-related genes Mox and Evx. Our phylogenetic analyses and theavailable linkage data in mammalian genomes support an evolutionary scenario in which anancestor of Evx and Mox was linked to the ProtoHox cluster, and that a tandem duplication of alarge genomic region early in metazoan evolution generated the Hox and ParaHox clusters, plusthe cluster-neighbors Evx and Mox. The large `coupled¿ Hox-like cluster EvxHox/MoxParaHox wassubsequently broken, thus grouping the Mox and Evx genes to the Hox clusters, and isolating theParaHox cluster.

Industrial agglomerations and wage gradients: the Spanish economy in the interwar period

This paper gives new evidence on the relationship between integration and industrial agglomeration in the presence of scale economies, by testing directly one of the predictions that can be derived from Krugman (1991), that is, the existence of regional nominal wage gradients and its transformation following changes in trade regimes. Our case study analyzes the effects of the substitution of an open economy by a closed economy regime, exactly the opposite process studied by Hanson (1996, 1997). In Spain, during the interwar period, protectionist policies would have favored the loss of centrality of the coastal location (Barcelona) and the relative rise of central locations (such as Madrid). Our results indicate the existence of a wage gradient centered in Barcelona during the interwar period (1914-1930) and its weakening after 1925.

Spatial correlations and cross sections of clusters in the A + B -> 0 reaction

We consider the distribution of cross sections of clusters and the density-density correlation functions for the A+B¿0 reaction. We solve the reaction-diffusion equations numerically for random initial distributions of reactants. When both reactant species have the same diffusion coefficients the distribution of cross sections and the correlation functions scale with the diffusion length and obey superuniversal laws (independent of dimension). For different diffusion coefficients the correlation functions still scale, but the scaling functions depend on the dimension and on the diffusion coefficients. Furthermore, we display explicitly the peculiarities of the cluster-size distribution in one dimension.

Industrial agglomerations and wage gradients: the Spanish economy in the interwar period

This paper gives new evidence on the relationship between integration and industrial agglomeration in the presence of scale economies, by testing directly one of the predictions that can be derived from Krugman (1991), that is, the existence of regional nominal wage gradients and its transformation following changes in trade regimes. Our case study analyzes the effects of the substitution of an open economy by a closed economy regime, exactly the opposite process studied by Hanson (1996, 1997). In Spain, during the interwar period, protectionist policies would have favored the loss of centrality of the coastal location (Barcelona) and the relative rise of central locations (such as Madrid). Our results indicate the existence of a wage gradient centered in Barcelona during the interwar period (1914-1930) and its weakening after 1925.