Analyzing Consumer’s Behaviour in Risk and Uncertainty Situations

In the paper we will generalize the Slutsky Equation in risk and uncertainty situations using the compensated and uncompensated demand and some local measures of risk aversion. We will obtain a nonlinear optimization problem of maximizing the expected utility; this problem will be solved using the Kuhn-Tucker method. We use the results to analyze the income and substitution effects of price changes on demand in risk and uncertainty conditions.Compensated demand, risk aversion, Slutsky Equation, uncertainty, uncompensated demand

Modeling techniques related to taxation policies when dealing with negative externalities

Recently, in February 2006, the Romanian government has approved the introduction of the tax on vices – on the products heavily affected the health if consumed (cigarettes and alcohol) - The tax set up is 10 euro/1.000 cigarettes, meaning 20 eurocents/cigarette pack, and 200 euro/hl alcohol. It is estimated that the measure will lead to significant price increasing and also to budgetary revenue increasing. It is estimated that the price for a cigarette package will increase in average with 37% - 38% - conforming to a study conducted by Phillip Morris International. Following this decision, the paper purpose is to analyze the impact of the introduction of the tax on vices on the social welfare trough a generalized mathematical model, suitable for the economies where negative externalities are present. Particularly, the model is suitable to analyze the tobacco consumption consequences, as this is one of the possible sources for negative externalities in an economy. Before presenting the modeling techniques, the paper contains an introduction part with data from the Romanian tobacco market and with arguments related to taxes on the tobacco consumption.modeling techniques, negative externalities, tobacco, taxation policies, social welfare.

Optimal Labor Contracts with Asymmetric Information and More than Two Types of Agent

In the paper we discuss the optimal labor agreements between workers and firms in the situation of asymmetric information. Using a standard adverse selection model, we analyze the optimality of the labor contracts when it is the firm which has private information affecting the results of the contractual relationship. We propose an alternative procedure to solve the optimization problem, using the informational rents as variables. In the last part of the paper we derive and comment the features of the optimal labor contracts in asymmetric information

Adverse selection model regarding tobacco consumption

The impact of introducing a tax on tobacco consumption can be studied trough an adverse selection model. The objective of the model presented in the following is to characterize the optimal contractual relationship between the governmental authorities and the two type employees: smokers and non-smokers, taking into account that the consumers’ decision to smoke or not represents an element of risk and uncertainty. Two scenarios are run using the General Algebraic Modeling Systems software: one without taxes set on tobacco consumption and another one with taxes set on tobacco consumption, based on an adverse selection model described previously. The results of the two scenarios are compared in the end of the paper: the wage earnings levels and the social welfare in case of a smoking agent and in case of a non-smoking agent.modeling techniques, adverse selection, tobacco, taxation policies, social welfare

Estudio de soluciones para resolver las filtraciones en la cerrada de la presa de Alloz (Navarra). Estudio geológico, estudio hidrológico y estudio geotécnico

[EN] The Alloz dam, located in the Navarre community, was built in 1930. Since its use until now, there have been large leaks because this vault dam is located in an area of ¿¿associated gypsum outcrops to the Keuper that have resulted in leaks of considerable flow. After continued attempts to correct the situation, today considerable leaks continue to occur on the right bank of the dam, so the objective of this work is to carry out a definitive solution to the problem. Prior to the study of solutions and the choice of the solution to be executed, the corresponding previous studies have been carried out, such as the geological, hydrological and geotechnical study. As a solution, it has been decided to perform injections in two differentiated phases: a first phase by means of a stable mixture of cement, clay, water and sand, and a second one, by means of an unstable mixture of cement slurry. The first of the phases will aim to fill the larger cavities or holes existing in the rock mass, while the second phase, carried out interspersed with the first, will aim to fill the thinnest cracks that have been left free. For this, it is decided to execute a group of injections with a total length of 335 meters that covers both the axis of the dam and both margins of the closed one.[CA] La presa de Alloz, situada a la comunitat foral de Navarra, va ser construïda el 1930. Des de la seua posada en ús fins l'actualitat s'han produït grans filtracions en la tancada a causa de que aquesta presa es troba situada en una zona d'afloraments guixencs associats al Keuper que han donat lloc a fuites de considerable cabal. Després d'intents continuats per corregir la situació, a dia de hui se segueixen produint filtracions considerables en la marge dreta de la presa, per la qual cosa l'objectiu del present treball és dur a terme una solució definitiva per al problema. Prèviament a l'estudi de solucions i a l'elecció de la solució a executar, s'han portat els corresponents estudis previs, com són l'estudi geològic, hidrològic i geotècnic. Com a solució s'ha optat per realitzar una pantalla d'injeccions en dues fases diferenciades: una primera fase mitjançant una barreja estable de ciment, argila, aigua i sorra, i una segona, mitjançant barreja inestable de beurada de ciment. La primera de les fases tindrà com a objectiu omplir els buits o cavitats més grans que hi ha al massís, mentre que la segona fase, realitzada de forma intercalada amb la primera, tindrà com a objectiu omplir les fissures més fines que hagen quedat lliures. Per a això, es decideix executar una pantalla d'una longitud total de 335 metres que cobreix tant l'eix de la presa com ambdues marges de la tancada.[ES] La presa de Alloz, situada en la comunidad foral de Navarra, fue construida en 1930. Desde su puesta en uso hasta la actualidad se han producido grandes filtraciones en la cerrada debido a que esta presa bóveda se encuentra situada en una zona de afloramientos yesosos asociados al Keuper que han dado lugar a fugas de considerable caudal. Tras intentos continuados por corregir la situación, a día de hoy se siguen produciendo filtraciones considerables en la margen derecha de la presa, por lo que el objetivo del presente trabajo es llevar a cabo una solución definitiva para el problema. Previamente al estudio de soluciones y a la elección de la solución a ejecutar, se han llevado los correspondientes estudios previos, como son el estudio geológico, hidrológico y geotécnico. Como solución se ha optado por realizar una pantalla de inyecciones en dos fases diferenciadas: una primera fase mediante una mezcla estable de cemento, arcilla, agua y arena, y una segunda, mediante mezcla inestable de lechada de cemento. La primera de las fases tendrá como objetivo rellenar los huecos o cavidades de mayor tamaño existentes en el macizo, mientras que la segunda fase, realizada de forma intercalada con la primera, tendrá como objetivo rellenar las fisuras más finas que hayan quedado libres. Para ello, se decide ejecutar una pantalla de una longitud total de 335 metros que cubra tanto el eje de la presa como ambas márgenes de la cerrada.Dumitru, VM. (2018). Estudio de soluciones para resolver las filtraciones en la cerrada de la presa de Alloz (Navarra). Estudio geológico, estudio hidrológico y estudio geotécnico. http://hdl.handle.net/10251/106023Archivo delegad

USE OF LIQUID FERTILIZERS BASED ON HUMATES EXTRACTED FROM LIGNITE IN WASTE DUMPS RECULTIVATION

Four liquid fertilizers based on humates obtained from lignite were developed and tested. The fertilizers were applied on the waste dump resulted from lignite open cast covered with fertile soil, at maize and alfalfa crops. The application of liquid fertilizers based on humates led to very significant increase of maize grain and alfalfa yields. The production reached the level of yields obtained in the area on land that was not affected by mining activities. The alfalfa plants concentration of macro elements and micro elements belongs to the ”normal” domain. The maize leaves had scarce nitrogen, potassium, copper, iron, and manganese contents and normal phosphorus and zinc contents