The Politics of Growth: Can Lobbying Raise Growth and Welfare?

This paper aims at analyzing the eects of lobbying over economic growth and primarily welfare. We model explicitly the interaction be- tween policy-makers and rms in a setup where the latter undertakes political contributions to the former in exchange for more restrictive market regulations which induce exit and enhance the protability of the market. In a sectorial equilibrium, despite stimulating growth, lobbying restricts the market structure and reduces welfare when com- pared to the free-entry outcome. However, once general equilibrium considerations are taken into account, we nd that lobbying may im- prove welfare over a welfare maximizing free-entry equilibrium, by means of an expansion in aggregate demand. This introduces a new paradigm in the literature about the eects of lobbying over economic performance. JEL codes: D72, L13, O31

Endogenous spillovers in the trade-off between centralization and decentralization

In this paper, we revisit the classical trade-o between centralized and decentralized provision of local public goods, in a setting where in- terregional spillovers depend on the level of a national public good. We compare the standard benevolent planner approach with a political econ- omy in which decisions, in a centralized system, are undertaken by a non-cooperative legislature with no separation of powers. We observe that the policy-maker in a centralized system is able to play both with local public goods and spillovers, a mechanism that is not available un- der a decentralized system. When compared to the traditional exogenous spillovers assumption, this improves the case for centralization under the standard benevolent planner approach. However, the same is not neces- sarily true in the non-cooperative legislature, as in this case the interests of the legislator do not need to be aligned with those of the society. Fi- nally, we extend the traditional political economy analysis by considering a legislature in which decisions are undertaken by dierent committees (separation of powers), and show that it performs better than the original non-cooperative legislature, greatly improving the case for centralization. JEL codes: D70, H11, H41, H70

Digging Out the PPP Hypothesis: an Integrated Empirical Coverage

We use several popular tests to test the validity of the Purchasing Power Parity (PPP) hypothesis. In particular, we analyze four classes of tests { standard univariate unit root tests, co-integration, panel unit root tests and unit root tests for nonlinear frameworks {, for a dataset consisting of 20 bilateral exchange rates. Through this approach, we ascertain the eectiveness of each methodology in assessing the validity of PPP. Overall, our results suggest little evidence to support PPP. Among the conducted tests, the panel analysis of nonstationarity idiosyncratic and common components provides the richest insights by disentangling the possible sources of non-stationarity of real exchange rates. The relevance of using price indexes with dierent characteristics is also pinpointed.PPP; Real exchange rate; Unit roots; Co-integration; Panel; Nonlinear models; Cross-sectional dependence

Disk and elliptical galaxies within renormalization group improved gravity

The paper is about possible effects of infrared quantum contributions to General Relativity on disk and elliptical galaxies. The Renormalization Group corrected General Relativity (RGGR model) is used to parametrize these quantum effects. The new RGGR results presented here concern the elliptical galaxy NGC 4374 and the dwarf disk galaxy DDO 47. Using the effective approach to Quantum Field Theory in curved background, one can argue that the proper RG energy scale, in the weak field limit, should be related to the Newtonian potential. In the context of galaxies, this led to a remarkably small variation of the gravitational coupling G, while also capable of generating galaxy rotation and dispersion curves of similar quality to the the best dark matter profiles (i.e., the profiles that have a core).Comment: 5 pages. This paper is based on a talk given by D.C. Rodrigues at the I CosmoSul meeting (Rio de Janeiro, RJ - Brazil. August, 01-05, 2011). To be published in AIP conference Proceeding

Advanced Control for Energy Management of Grid-Connected Hybrid Power Systems in the Sugar Cane Industry

This work presents a process supervision and advanced control structure, based on Model Predictive Control (MPC) coupled with disturbance estimation techniques and a finite-state machine decision system, responsible for setting energy productions set-points. This control scheme is applied to energy generation optimization in a sugar cane power plant, with non-dispatchable renewable sources, such as photovoltaic and wind power generation, as well as dispatchable sources, as biomass. The energy plant is bound to produce steam in different pressures, cold water and, imperiously, has to produce and maintain an amount of electric power throughout each month, defined by contract rules with a local distribution network operator (DNO). The proposed predictive control structure uses feedforward compensation of estimated future disturbances, obtained by the Double Exponential Smoothing (DES) method. The control algorithm has the task of performing the management of which energy system to use, maximize the use of the renewable energy sources, manage the use of energy storage units and optimize energy generation due to contract rules, while aiming to maximize economic profits. Through simulation, the proposed system is compared to a MPC structure, with standard techniques, and shows improved behavior.Ministerio de Economía y Competitividad CNPq401126/2014-5Ministerio de Economía y Competitividad CNPq303702/2011-7Ministerio de Economía y Competitividad DPI2016-78338-

Binary Search Algorithm for Mixed Integer Optimization: Application to energy management in a microgrid

This paper presents a binary search algorithm to deal with binary variables in mixed integer optimization problems. One example of this kind of problem is the optimal operation of hydrogen storage and energy sale and purchase into a microgrids context. In this work was studied a system composed by a microgrid that has a connection with the external electrical network and a charging station for electric cars. The system modeling was carried out by the Energy Hubs methodology. The proposed algorithm transforms the MIQP (Mixed Integer Quadratic Program) problem into a QP (Quadratic Program) that is easier to solve. In this way the overall control task is carried out the electricity purchase and sale to the power grid, maximizes the use of renewable energy sources, manages the use of energy storages and supplies the charge of the parked vehicles.Ministerio de Economía y Competitividad DPI2013-46912-C2-1-RUniversidad de Sevilla CNPq401126/2014-5Universidad de Sevilla CNPq303702/2011-

Thermodynamics of Small Magnetic Particles

In the present paper, we discuss the interpretation of some of the results of the thermodynamics in the case of very small systems. Most of the usual statistical physics is done for systems with a huge number of elements in what is called the thermodynamic limit, but not all of the approximations done for those conditions can be extended to all properties in the case of objects with less than a thousand elements. The starting point is the Ising model in two dimensions (2D) where an analytic solution exits, which allows validating the numerical techniques used in the present article. From there on, we introduce several variations bearing in mind the small systems such as the nanoscopic or even subnanoscopic particles, which are nowadays produced for several applications. Magnetization is the main property investigated aimed for two singular possible devices. The size of the systems (number of magnetic sites) is decreased so as to appreciate the departure from the results valid in the thermodynamic limit; periodic boundary conditions are eliminated to approach the reality of small particles; 1D, 2D and 3D systems are examined to appreciate the differences established by dimensionality is this small world; upon diluting the lattices, the effect of coordination number (bonding) is also explored; since the 2D Ising model is equivalent to the clock model with q=2 degrees of freedom, we combine previous results with the supplementary degrees of freedom coming from the variation of q up to q=20. Most of the previous results are numeric; however, for the case of a very small system, we obtain the exact partition function to compare with the conclusions coming from our numerical results. Conclusions can be summarized in the following way: the laws of thermodynamics remain the same, but the interpretation of the results, averages and numerical treatments need special care for systems with less than about a thousand constituents, and this might need to be adapted for different properties or devices.Fil: Vogel, Eugenio. Universidad de La Frontera; Chile. Center for the Development of Nanoscience and Nanotechnology; ChileFil: Vargas, Patricio. Center for the Development of Nanoscience and Nanotechnology; Chile. Universidad Técnica Federico Santa María; ChileFil: Saravia, Gonzalo. Universidad de La Frontera; ChileFil: Valdes, Julio. Universidad de La Frontera; ChileFil: Ramirez Pastor, Antonio Jose. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Física Aplicada "Dr. Jorge Andrés Zgrablich". Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto de Física Aplicada "Dr. Jorge Andrés Zgrablich"; ArgentinaFil: Centres, Paulo Marcelo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Física Aplicada "Dr. Jorge Andrés Zgrablich". Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto de Física Aplicada "Dr. Jorge Andrés Zgrablich"; Argentin

Active Learning of Physics: synergy of teaching strategies

We report on the application of Tutorial for Introductory Physics and Interactive Lecture Demonstrations (ILD’s) in the Mechanics course taken by engineering students at the Universidad Nacional de San Juan. Argentina. A pre/post test quasi experimental design was implemented to compare the learning gains of two previously formed complete groups of engineering students. One of the groups continued with the traditional instruction, while in the experimental group active learning strategies were introduced in two steps: the first experiment included only Tutorials, while in the second experiment ILD’s were added. Conceptual knowledge was measured with the Force Concept Inventory (FCI) test, while the institutional evaluation included three rather traditional problem solving written exams. A normalized gain of g=0.27 was obtained in the control course, well above the average for traditional instruction, as indicated by the wide study of Hake. The experimental instruction yielded g=0.56 in the first application and g=0.62 in the second experiment, indicating the synergy of using together coherent teaching strategies. The most striking result is the high degree of student success in the institutional evaluation, which increased the fraction of retained (successful) student to more than double that obtained by the traditional instruction. Implications for educational reform in similar educational systems are discussed.Como ejemplo de aplicación de las metodologías de aprendizaje activo en cursos de física básica para carreras de ingeniería se describen dos experimentos sucesivos. En el primero, se implementó la estrategia “Tutoriales para Física Introductoria” y se la comparó con un curso donde se siguió practicando la enseñanza tradicional, mientras que en la segunda experiencia se incorporaron a los Tutoriales algunas clases estructuradas de acuerdo a la estrategia “Clases Interactivas Demostrativas” (CID). Estas experiencias fueron realizadas en los cursos normales de Física Básica para estudiantes de ingeniería de la Universidad Nacional de San Juan (Argentina). Se utilizó un diseño de comparación de grupos preestablecidos, con determinación del conocimiento pre y post instrucción mediante el test Force Concept Inventory. Los cursos con estrategias de aprendizaje activo lograron niveles de aprendizaje muy satisfactorios, distribuidos en la mayoría de los estudiantes de la muestra y obteniendo, en promedio, ganancias intrínsecas de g=0.56 en la primera experiencia y g=0.62 en la segunda experiencia, mientras que el curso testigo, con enseñanza tradicional, se obtuvo g=0.27. Estos resultados pueden considerarse típicos de la importante mejoría que puede lograrse en los aprendizajes utilizando estrategias de aprendizaje activo de la física de una manera coherente.Fil: Godoy, Paulo. Universidad Nacional de San Juan; ArgentinaFil: Benegas, Julio Ciro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Matemática Aplicada de San Luis "Prof. Ezio Marchi". Universidad Nacional de San Luis. Facultad de Ciencias Físico, Matemáticas y Naturales. Instituto de Matemática Aplicada de San Luis "Prof. Ezio Marchi"; ArgentinaFil: Pandiella, Susana Beatriz. Universidad Nacional de San Juan; Argentin