Student time allocation and educational production functions

In this paper we aim to remedy some shortcomings in the economic literature on university student absenteeism and academic performance. We start by introducing a simple theoretical model in which students decide the optimal allocation of their time between lecture attendance, self-study and leisure. Under some specific assumptions, we find a positive relationship between lecture attendance and time devoted to self-study in each course, from which we infer that estimates of student performance regressions which omit self-study might be biased. Thus, we estimate an academic performance regression using data from first year undergraduate students of economics in the academic year 1998-99 at the University of Ancona (Italy) and find evidence that once self-study time is controlled for, the positive and significant effect of lecture attendance for some courses disappears. This is likely to be important especially when student performance regressions are used to evaluate the effectiveness of course attendance and to inform the debate on the introduction of mandatory attendance on some courses to enhance student performance.course attendance, student performance, time allocation

On Short-Term Contracts Regulations

We present a theoretical as well as empirical analysis of the impact of employment regulations on permanent and temporary employment. We consider three different forms of such regulations, namely insider protection, fixed term contract regulations, and legislation on temporary work agencies, and we present some empirical evidence as regards total, female and young employees based on a panel of nine European countries. We show that these three types of regulations have different impacts on the employment performances of those countries. Moreover, these institutions act asymmetrically along the business cycle. The most notable findings are that lower employment protection leads to the substitution of permanent employees by termporary ones with an insignificant net effect on the total; more flexible regulations on fixed term contracts have a beneficial effect on temporary as well as permanent employment among young people; flexible regulations on temporary work agencies have a positive impact on temporary employment, while they may reduce permanent employment.Fixed Term Contracts, Temporary Work Agencies, Temporary Employment, Labour Market Institutions, Employment Protection

Can Market Power influence Employment, Wage Inequality and Growth ?

We introduce an efficiency-wage mechanism into an innovation-driven growth model. Due to informational problems, the labour market is segmented and homogeneous workers may be employed either in a non-competitive intermediate sector or in a competitive research one. We analyse the impact that variations in the monopoly power of the intermediate firms may have on unemployment, wage inequality and growth. We find that the lower the product market competition in the intermediate sector, the higher the research employment, the lower the intermediate sector employment, the higher the aggregate growth rate. Growth and inequality are negatively correlated whereas growth and unemployment are positively correlated. The last two results are obtained through numerical simulations.Efficiency wages; research and development; endogenous growth; market power

Investigation of Interfacial and Transport properties of LIBs/NIBs anodes and commercial SOFCs

In this thesis work, two types of electrochemical energy systems (EESs) have been studied, i.e.: electrochemical energy storage by Li-/Na-ion batteries, and electrochemical energy conversion by Solid Oxide Fuel Cells. Energy production worldwide is moving toward renewable energy sources to decrease the greenhouse gases emissions. In this context, electrochemical energy systems will be in the very next future the key enablers for the production and storage of green energy. Furthermore, Li-ion batteries will play the main role for the transport electrification. To achieve this goal, several aspects of EESs needs to be studied and optimized, considering both performances and sustainability. Speaking of Li-ion batteries, graphite is the state-of-the-art anode material. However, it must be partially or totally replaced because of its low specific capacity (372 mAh g-1 ) as well as its introduction into the critical raw materials list of the European Union. SnO2 is a potential candidate because of its high theoretical capacity (1484 mAh g-1 ), environmentally friendliness, and at the moment is not considered a critical raw material by the European Union. However, it suffers of cycling instability due to the structural rearrangements upon cycling, and large voltage hysteresis. In this regard, three different nanocomposite anodes based on SnO2 have been synthesized and characterized in terms of both performance and interfacial and transport properties. The effect of an active/inactive matrix, as well as the morphology of SnO2 has been deeply studied. As a result, the studied SnO2-based anodes can offer promising and tailored performances in terms of energy density, energy efficiency, and rate capability according to the end user application. Speaking of Na- ion batteries, a Fe3O4-based anode was studied as a sustainable high-power anode material. In this regard, the material was structurally, morphologically, and electrochemically characterized. A deep electrochemical characterization in terms of interfacial and transport properties has been carried out by means of cyclic voltammetry at different scan rates, potentiostatic electrochemical impedance spectroscopy, and ex-situ Raman spectroscopy. The last section is focused on electrochemical energy conversion by Solid Oxide Fuel Cells. In this regard, a new technique, based on electrochemical impedance spectroscopy and the study of the distribution of relaxation times, has been proposed for assessing the state-of-health of the SOFC under real operating conditions. Firstly, an extended experimental campaign has been pursued to build a meaningful equivalent circuit model. Subsequently, an a priori known stress agent was applied to validate the obtained electrochemical model

Recuperación del cuerpo de Mujeres Mayores a partir de la mediación de los Programas de Salud

Desde mediados del siglo XX se reconoce mundialmente el envejecimiento continuo y constante de la población. Este grupo muestra particularidades que son abordadas desde diferentes espacios sanitarios. El más reconocido de ellos, los Programas de salud tienen como una de sus principales metas 'controlar' las enfermedades; en este caso las asociadas con el proceso de envejecimiento. El trabajo aborda la emergencia del cuerpo a partir de la implementación de dichas políticas. El objetivo ha sido describir las implicancias que surgen en la recuperación del cuerpo de mujeres Mayores, cuyas prácticas culturales y roles sociales han ocultado a sus sensaciones y proyecciones cotidianas. Se implementó una metodología cualitativa a partir de relatos de experiencias de mujeres Mayores que participan de las actividades prescritas desde los Programas de Salud propuestos por el Instituto Nacional de Servicios Sociales para Jubilados y Pensionados, en los lugares donde dichas actividades se realizan. Los resultados obtenidos marcan la re-emergencia de un cuerpo que el contexto y la historia de esas mujeres se ocuparon de borrar de las prioridades cotidianas, y que las enfermedades ponen de manifiesto desde el lugar del dolor y la pérdida, habilitando a sensaciones, sentimientos, goces, que se creían perdido

Identifiability and singular locus of secant varieties to Grassmannians

Secant varieties are among the main protagonists in tensor decomposition, whose study involves both pure and applied mathematical areas. Grassmannians are the building blocks for skewsymmetric tensors. Although they are ubiquitous in the literature, the geometry of their secant varieties is not completely understood. In this work we determine the singular locus of the secant variety of lines to a Grassmannian Gr(k,V) using its structure as SL(V)-variety. We solve the problems of identifiability and tangential-identifiability of points in the secant variety: as a consequence, we also determine the second Terracini locus to a Grassmannian.Comment: 25 page

American options with acceleration clauses

Acceleration clauses shorten the residual life of an option when an acceleration condition is met. Acceleration clauses are frequent in warrants, American call options on traded stocks. In warrants with the acceleration clause, if an index (e.g. the average underlying stock) triggers an acceleration threshold, the American call option can be exercised on a much shorter maturity (e.g. 30 days). The actual time-to-maturity of an American option with an acceleration condition is therefore stochastic. In order to evaluate these contracts we first reduce the generic American option with stochastic time-to-maturity to a compound American option with constant maturity, and provide estimates for their prices. Finally we propose an efficient algorithm to price American call options with the acceleration clause in a binomial setting

Individual Earnings, International Outsourcing and Technological Change.

The aim of this paper is to empirically evaluate the relative effects of international outsourcing of materials and services and of ICT capital deepening on wage inequality between blue and white collars in the Italian manufacturing industry during the period 1985-1999. We merge an administrative data set on workers\' wages and individual characteristics with data on imported inputs from Italian input-output tables and other sector-level variables. Our results confirm that both material and service outsourcing widen the skilled/unskilled wage gap while ICT capital deepening positively affects real wages regardless of the worker\'s status. However, important differences emerge when the overall sample is split between traditional and innovative sectors.International Outsourcing, ICT, Wage Inequality