The Vector Curvaton

We analyze a massive vector field with a non-canonical kinetic term in the action, minimally coupled to gravity, where the mass and kinetic function of the vector field vary as functions of time during inflation. The vector field is introduced following the same idea of a scalar curvaton, which must not affect the inflationary dynamics since its energy density during inflation is negligible compared to the total energy density in the Universe. Using this hypothesis, the vector curvaton will be solely responsible for generating the primordial curvature perturbation \zeta. We have found that the spectra of the vector field perturbations are scale-invariant in superhorizon scales due to the suitable choice of the time dependence of the kinetic function and the effective mass during inflation. The preferred direction, generated by the vector field, makes the spectrum of \zeta depend on the wavevector, i.e. there exists statistical anisotropy in \zeta. This is discussed principally in the case where the mass of the vector field increases with time during inflation, where it is possible to find a heavy field (M >> H) at the end of inflation, making the particle production be practically isotropic; thus, the longitudinal and transverse spectra are nearly the same order which in turn causes that the statistical anisotropy generated by the vector field is within the observational bounds.Comment: LaTex file in Aipproc style, 6 pages, no figures. Prepared for the conference proceedings of the IX Mexican School of the DGFM-SMF: Cosmology for the XXIst Century. This work is entirely based on Refs. [23-26] and is the result of Andres A. Navarro's MSc thesi

Project based learning on industrial informatics: applying IoT to urban garden

Copyright (c) 2018 IEEEThe fast evolution of technologies forces teachers to trade content off for self-learning. PBL is one of the best ways to promote self-learning and simultaneously boost motivation. In this paper, we present our experience introducing project-based learning in the last year subject. New Internet of Things (IoT) topic allows us to carry out complete projects, integrating different technologies and tools. Moreover, the selection of open-source and standard free technologies makes easy and cheap the access to hardware and software platforms used. We carefully have picked communication, data management, and programming tools that we think would be attractive to our students. They can start making fast prototyping with little initial skills and, at the same time, these are serious and popular tools widely used in the industry. In this paper, we report on the design of a project-based learning for our course and the impact this has on the student satisfaction and motivation. Surveys taught us that tuning the courses towards developing real projects on the field, has a large impact on acceptance, learning objectives achievements and motivation towards the course content.”I Plan Propio Integral de Docencia de la Universidad de Málaga” y Proyecto de Innovación Educativa PIE17/085, de la Universidad de Málaga. Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Multinationals and Linkages: An Empirical Investigation

Several recent papers have used plant-level data and panel econometric techniques to carefully explore the existence FDI externalities. One conclusion that emerges from this literature is that it is difficult to find evidence of positive externalities from multinationals to local firms in the same sector (horizontal externalities). In fact, many studies find evidence of negative horizontal externalities arising from multinational activity while confirming the existence of positive externalities from multinationals to local firms in upstream industries (vertical externalities). In this paper we explore the channels through which these positive and negative externalities may be materializing, focusing on the role of backward linkages. In particular, we criticize the common usage of the domestic sourcing coefficient as an indicator of a firm?s linkage potential and propose an alternative, theoretically derived indicator. We then use plant-level data from several Latin American countries to compare multinationals? linkage potential to that of domestic firms. We find that multinational?s linkage potential in Brazil, Chile and Venezuela is higher than for domestic firms. For Mexico, we cannot reject the hypothesis that foreign and local firms have similar linkage potential. Finally, we discuss the relationship between this finding and the conclusions that emerge from the recent empirical literature.Foreign Direct Investment, Multinational Firms, Linkages, Spillovers, Economic Development.

Trade, Diffusion and the Gains from Openness

Building on Eaton and Kortum's (2002) model of Ricardian trade, Alvarez and Lucas (2005) calculate that a small country representing 1% of the world's GDP experiences a gain of 41% as it goes from autarky to frictionless trade with the rest of the world. But the gains from openness, which includes not only trade but all the other ways through which countries interact, are arguably much higher than the gains from trade. This paper presents and then calibrates a model where countries interact through trade as well as diffusion of ideas, and then quantifies the overall gains from openness and the role of trade in generating these gains. Having the model match the trade data (i.e., the gravity equation) and the observed growth rate is critical for this quantification to be reasonable. The main result of the paper is that, compared to the model without diffusion, the gains from openness are much larger (206%-240%) and the gains from trade are smaller (13%-24%) when diffusion is included in the model. This last result is a consequence of a novel feature of the model, namely that trade and diffusion are substitutes, implying that trade generates smaller gains when diffusion is present.

Economic Polarization Through Trade: Trade Liberalization and Regional Growth in Mexico

economic growth, regional disparities, trade, integration, polarization, Mexico

Externalities and Growth

Externalities play a central role in most theories of economic growth. We argue that international externalities, in particular, are essential for explaining a number of empirical regularities about growth and development. Foremost among these is that many countries appear to share a common long run growth rate despite persistently different rates of investment in physical capital, human capital, and research. With this motivation, we construct a hybrid of some prominent growth models that have international knowledge externalities. When calibrated, the hybrid model does a surprisingly good job of generating realistic dispersion of income levels with modest barriers to technology adoption. Human capital and physical capital contribute to income differences both directly (as usual), and indirectly by boosting resources devoted to technology adoption. The model implies that most of income above subsistence is made possible by international diffusion of knowledge.

THE RELATIONSHIP BETWEEN SOFTWARE PROTECTION AND PIRACY: EVIDENCE FROM EUROPE

piracy, enforcement, panel data, copyright