Public infrastructure, private capital and the performance of manufactures: short and long run effects

Despite the general idea among economists that public capital is a necessary but not sufficient condition for regional economic development, there is not consensus on the quantification of its effect. It is our belief that the variety of results on infrastructure impact in the economic literature is due to the fact that it depends on a series of factors. Among them we can think of a different sectoral effect, the level of economic development in the area, so as the amount of the existing public capital stocks and their interaction with infrastructures in other regions. In this paper we focus on this latter condition, having into account that the evidence on public capital spillovers obtained in other studies is not homogeneous. This way, whereas in Holtz-Eakin and Schwartz (1995) the stock of highways in a state does not suppose benefits in productivity further its borders, Mas et al. (1997) obtain that the infrastructural endowment in the neighbours can be important. Using different functional forms, the first purpose of this paper is to shed light into the existence of public capital spillovers considering not only the physical interaction among regions but also other forms of relationship such as trade linkages. In a second step, we follow a discusion on the existence of other economic externalities that in case of not being considered could be the reason why we obtain biased estimations for regional returns to scale. Both purposes are treated through the use of spatial econometrics techniques in the Spanish regional case. Keywords: Public capital, Infrastructure Spillovers, External Effects, Spatial Econometrics

The Tcc = DD* molecular state

We show that the molecule-like configuration of DD^* enables weak binding with two realistic potential models (Bhaduri and Grenoble AL1). Three-body forces may increase the binding and strengthen the cc diquark configuration. As a signature we propose the branching ratio between radiative and pionic decay.Comment: 19 pages, 18 figures, revised version, to be published in Few-Body System

Podcasts as a conversational pedagogy

The use of technology such as podcasts, social networking sites, wikis, and Google docs for communicating information which supports teaching and learning in tertiary institutions is well documented (Bates, 2005). These tools have been shown to enhance traditional lectures and tutorials (Salmon, 2007). Little attention, however, has been given to the use of conversational approaches when using these tools and their potential in developing alternative pedagogical approaches to teaching. This article examines the use of a conversational style podcast in an online pre-service early childhood teacher education programme. The podcasts were initially used to disseminate information and respond to the students’ needs, however, their conversational use revealed a number of unexpected outcomes. Analysis of the podcast conversations that occurred between the two lecturers, and the student feedback to these, were used to identify unexpected outcomes for students enrolled in the programme. These included the ‘humanising’ of the e-learning environment and the sense of community that emerged. This paper argues that the affordance of conversational podcasts personalises the e-learning environment, enhances students’ and lecturers’ motivation, and engenders a greater connectedness with the university context

Proton Spin in Deep Inelastic Scattering

So far the analyses of the polarized structure functions of the proton and neutron have been limited to the evaluation of their integrals and comparing them to the prediction of the static quark model of the nucleon. We extended our analysis to the x dependence of the polarized structure functions and observe: the measured structure function excellently agrees with the prediction of the static quark model for Bjorken $x>0.2$ and drops rapidly for $x<0.2$. It is suggested that for Bjorken $x>0.2$ electrons get scattered on the undamaged constituent quarks (alias valence quarks) denoted as quasi-elastic scattering on the constituent quarks and for $x<0.2$ the constituent quarks fragment. In the fragmentation strong interaction is involved which does not preserve the polarization.Comment: 6 pages, 4 figures, Presented at the workshop on Diffraction and Low-x, Reggio Calabria, Aug. 26-Sept. 1, 201

SPATIAL MOBILITY AND LOCATION CHOICES OF HIGHLY SKILLED WORKERS

The aim of the present paper is to shed light on the determinants of geographical mobility and location choices of skilled individuals across the European regions. The most talented workers, e.g. inventors, move for a number of reasons, contributing in this manner to the geographical diffusion of knowledge as well as to reshape the geography of talent. Thus, geographic areas constitute nodes through which talent circulate, bringing knowledge from one place to another. By means of a gravity model, we will test whether social proximity between inventors’ communities and the so-called National System of Innovation drive in- and out-flows of inventors between pairs of regions, above and beyond physical separation, as well as other pulling factors (amenities, economic conditions, and the like). As for the econometrics is concerned, in order to accommodate our estimations to the count nature of our dependent variable and the high number of zeros in it, zero inflated negative binomial models are used. Our first results point out to the importance of, still, geographical proximity in driving this phenomenon. However, social relationships, as well as institutional, or technological and cultural proximities, are also playing a preponderant role in mediating the mobility patterns of inventors across the European geography.

Double heavy baryons and dimesons

We critically examine the question whether the cc\bar{q}\bar{q} dimeson is bound or not.Comment: Talk presented at the Fourth Int. Conf. on Perspectives in Hadronic Physics, ICTP - Trieste; May 12-16, 2003; to be published in European Journal of Physics A; 6 pages LaTe