Accounting for unobservables in production models:management and inefficiency

This paper explores the role of unobserved managerial ability in production and its relationship with technical efficiency. Previous analyses of managerial ability have been based on strong assumptions about its role in production or on the use of proxies. We avoid these limitations by introducing managerial ability as an unobserved random variable in a translog production function. The resulting empirical model can be estimated as a stochastic production frontier with random coefficients.Managerial ability, technical efficiency, production frontier, random coefficients model, maximum simulated likelihood.

Factores asociados con mortalidad perioperatoria a 30 días en cirugía no cardiaca en Bogotá, Colombia

La identificación de factores de riesgo asociados a morbimortalidad perioperatoria permite tomar acciones para optimizar la condición de los pacientes previo a la cirugía, disminuyendo así la morbimortalidad perioperatoria. Nuestro objetivo es determinar los factores asociados con la mortalidad perioperatoria en nuestra población, identificando los pacientes con mayor riesgo de presentar un desenlace fatal.The identification of risk factors associated with perioperative morbidity and mortality allows us to take actions to optimize the condition of patients prior to surgery, thus reducing perioperative morbidity and mortality. Our objective is to determine the factors related to perioperative mortality in our population, identifying the patients with the highest risk of presenting a fatal outcome

Grand canonical electronic density-functional theory: Algorithms and applications to electrochemistry

First-principles calculations combining density-functional theory and continuum solvation models enable realistic theoretical modeling and design of electrochemical systems. When a reaction proceeds in such systems, the number of electrons in the portion of the system treated quantum mechanically changes continuously, with a balancing charge appearing in the continuum electrolyte. A grand-canonical ensemble of electrons at a chemical potential set by the electrode potential is therefore the ideal description of such systems that directly mimics the experimental condition. We present two distinct algorithms: a self-consistent field method and a direct variational free energy minimization method using auxiliary Hamiltonians (GC-AuxH), to solve the Kohn-Sham equations of electronic density-functional theory directly in the grand canonical ensemble at fixed potential. Both methods substantially improve performance compared to a sequence of conventional fixed-number calculations targeting the desired potential, with the GC-AuxH method additionally exhibiting reliable and smooth exponential convergence of the grand free energy. Finally, we apply grand-canonical density-functional theory to the under-potential deposition of copper on platinum from chloride-containing electrolytes and show that chloride desorption, not partial copper monolayer formation, is responsible for the second voltammetric peak

Sistema detector de radiación UV a diferentes bandas de frecuencia

El campo de la detección y posterior medición de radiación ultravioleta ha alcanzado gran importancia en los últimos años, dado el crecimiento de diferentes campos de acción donde la radiación UV interviene, tales como desinfección de agua, manufactura de microprocesadores y monitoreo de actividad solar con fines de salubridad. El proyecto que aquí se expone es un sistema el cual permite detectar radiación UV a diferentes bandas de frecuencia y además seleccionar el rango de longitudes de onda sobre el cual se desea detectar radiación dentro del espectro UV.Ingeniero (a) ElectrónicoPregrad

Pending issues in protection, productivity growth, and poverty reduction

This paper selectively synthesizes much of the research on Latin American and Caribbean labor markets in recent years. Several themes emerge that are particularly relevant to ongoing policy dialogues. First, labor legislation matters, but markets may be less segmented than previously thought. The impetus to voluntary informality, which appears to be a substantial fraction of the sector, implies that the design of social safety nets and labor legislation needs to take a more integrated view of the labor market, taking into account the cost-benefit analysis workers and firms make about whether to interact with formal institutions. Second, the impact of labor market institutions on productivity growth has probably been underemphasized. Draconian firing restrictions increase litigation and uncertainty surrounding worker separations, reduce turnover and job creation, and poorly protect workers. But theory and anecdotal evidence also suggest that they, and other related state or union induced rigidities, may have an even greater disincentive effect on technological adoption, which accounts for half of economic growth. Finally, institutions can affect poverty and equity, although the effects seem generally small and channels are not always clear. Overall, the present constellation of labor regulations serves workers and firms poorly and both could benefit from substantial reform.Labor Markets,Labor Standards,Economic Theory&Research,Work&Working Conditions,Labor Management and Relations