Essays in partial identification and applications to treatment effects and policy evaluation.

Dans cette thèse, je me suis interessé à l’identification partielle des effets de traitements dans différents modèles de choix discrets avec traitements endogènes. Les modèles d’effets de traitement ont pour but de mesurer l’impact de certaines interventions sur certaines variables d’intérêt. Le type de traitement et la variable d’intérêt peuvent être défini de manière générale afin de pouvoir être appliqué à plusieurs différents contextes. Il y a plusieurs exemples de traitement en économie du travail, de la santé, de l’éducation, ou en organisation industrielle telle que les programmes de formation à l’emploi, les techniques médicales, l’investissement en recherche et développement, ou l’appartenance à un syndicat. La décision d’être traité ou pas n’est généralement pas aléatoire mais est basée sur des choix et des préférences individuelles. Dans un tel contexte, mesurer l’effet du traitement devient problématique car il faut tenir compte du biais de sélection. Plusieurs versions paramétriques de ces modèles ont été largement étudiées dans la littérature, cependant dans les modèles à variation discrète, la paramétrisation est une source importante d’identification. Dans un tel contexte, il est donc difficile de savoir si les résultats empiriques obtenus sont guidés par les données ou par la paramétrisation imposée au modèle. Etant donné, que les formes paramétriques proposées pour ces types de modèles n’ont généralement pas de fondement économique, je propose dans cette thèse de regarder la version nonparamétrique de ces modèles. Ceci permettra donc de proposer des politiques économiques plus robustes. La principale difficulté dans l’identification nonparamétrique de fonctions structurelles, est le fait que la structure suggérée ne permet pas d’identifier un unique processus générateur des données et ceci peut être du soit à la présence d’équilibres multiples ou soit à des contraintes sur les observables. Dans de telles situations, les méthodes d’identifications traditionnelles deviennent inapplicable d’où le récent développement de la littérature sur l’identification dans les modèles incomplets. Cette littérature porte une attention particuliere à l’identification de l’ensemble des fonctions structurelles d’intérêt qui sont compatibles avec la vraie distribution des données, cet ensemble est appelé : l’ensemble identifié. Par conséquent, dans le premier chapitre de la thèse, je caractérise l’ensemble identifié pour les effets de traitements dans le modèle triangulaire binaire. Dans le second chapitre, je considère le modèle de Roy discret. Je caractérise l’ensemble identifié pour les effets de traitements dans un modèle de choix de secteur lorsque la variable d’intérêt est discrète. Les hypothèses de sélection du secteur comprennent le choix de sélection simple, étendu et généralisé de Roy. Dans le dernier chapitre, je considère un modèle à variable dépendante binaire avec plusieurs dimensions d’hétérogéneité, tels que les jeux d’entrées ou de participation. je caractérise l’ensemble identifié pour les fonctions de profits des firmes dans un jeux avec deux firmes et à information complète. Dans tout les chapitres, l’ensemble identifié des fonctions d’intérêt sont écrites sous formes de bornes et assez simple pour être estimées à partir des méthodes d’inférence existantes.

Moderating effects of management control systems and innovation on performance. Simple methods for correcting the effects of measurement error for interaction effects in small samples

In the accounting literature, interaction or moderating effects are usually assessed by means of OLS regression and summated rating scales are constructed to reduce measurement error bias. Structural equation models and two-stage least squares regression could be used to completely eliminate this bias, but large samples are needed. Partial Least Squares are appropriate for small samples but do not correct measurement error bias. In this article, disattenuated regression is discussed as a small sample alternative and is illustrated on data of Bisbe and Otley (in press) that examine the interaction effect of innovation and style of use of budgets on performance. Sizeable differences emerge between OLS and disattenuated regression

Crisis civilizatoria y marginalidad : un estudio del movimiento punk.

Conocer mejor los punks canarios, verificando: a)Los punks representan un estilo subcultural que se caracteriza por unas actitudes radicalmente disconformes con el estado actual de las cosas. b) Ese radicalismo y disconformidad es bastante más intenso que el de los otros sectores de la sociedad. c) Los punks son un auténtico grupo, dada la cohesión e integración de sus miembros en torno a dichas actitudes además de otros aspectos: música, apariencia, etc. 403 sujetos: 204 de Bachillerato y Formación Profesional; 157 universitarios; 42 punks. Se distribuyó también por sexo, edad, estado civil, tipo de residencia, dependencia económica, profesión del padre e ingresos aproximados de la familia al mes. Se utilizó un diseño correlacional para determinar las relaciones existentes entre las actitudes que se pretenden medir y las diferentes categorías de sujetos. Las variables que se estudian son: radicalismo, antiautoritarismo, desconfianza en el futuro y tolerancia sexual. Las variables controladas: categoría social de los sujetos (universitarios, no universitarios y punks), orden de presentación de las escalas y el cuestionario, la tendencia a la aquiescencia, etc. 1. Cuestionario de datos personales. 2. Escala de antiautoritarismo de M. de Bethencourt. 3. Escala de radicalismo, de elaboración propia. 4. Escala de desconfianza en el futuro. 5. Escala de tolerancia sexual, elaborada por J. Barroso Ribal. 1. Pruebas de fiabilidad, por el método de Crombach. 2. Análisis factorial. 3. Correlación interfactorial. 4. Distribución de frecuencias. 5. Prueba T. 6. Análisis discriminante. 1. En el interior del colectivo punk, aquellos que más contribuyen con sus respuestas a que disminuyeran las puntuaciones medias, fueron los punks de Santa Cruz de Tenerife, contrariamente con los de La Laguna. 2. Respecto al factor sexualidad libre, aparece una distancia significativa entre las mujeres punks, que puntúan más alto y las mujeres universitarias. 3. Con respecto al grado de desconfianza en el futuro aparece una actitud combinada de escepticismo, inmediatismo y combatividad. 1. Según los resultados obtenidos en las cuatro escalas de actitudes, las hipótesis que se planteaban al principio han quedado demostradas. 2. Se ratifica que los punks, más que una simple categoría o sector social, poseen una identidad simbólica, ritual que les proporciona una cohesión o conciencia de grupo, que está ausente o está menos acentuado en otros conjuntos humanos que carecen de señas identificatorias específicas.

The simple macroeconomics of North and South in EMU. Bruegel Working Paper 2012/12, 30 July 2012

The euro area today consists of a competitive, moderately leveraged North and an uncompetitive, over-indebted South. Its main macroeconomic challenge is to carry out the adjustment required to restore the competitiveness of its southern part and eliminate its excessive public and private debt burden. This paper investigates the relationship between fiscal and competitiveness adjustment in a stylised model with two countries in a monetary union, North and South. To restore competitiveness, South implements a more restrictive fiscal policy than North. We consider two scenarios. In the first, monetary policy aims at keeping inflation constant in the North. The South therefore needs to deflate to regain competitiveness, which worsens the debt dynamics. In the second, monetary policy aims at keeping inflation constant in the monetary union as a whole. This results in more monetary stimulus, inflation in the North is higher, and this in turn helps the debt dynamics in the South. Our main findings are: •The differential fiscal stance between North and South is what determines real exchange rate changes. South therefore needs to tighten more. There is no escape from relative austerity. •If monetary policy aims at keeping inflation stable in the North and the initial debt is above a certain threshold, debt dynamics are perverse: fiscal retrenchment is self-defeating; •If monetary policy targets average inflation instead, which implies higher inflation in the North, the initial debt threshold above which the debt dynamics become perverse is higher. Accepting more inflation at home is therefore a way for the North to contribute to restoring debt sustainability in the South. •Structural reforms in the South improve the debt dynamics if the initial debt is not too high. Again, targeting average inflation rather than inflation in the North helps strengthen the favourable effects of structural reforms.

Why is the Greek economy collapsing? A simple tale of high multipliers and low exports. CEPS Commentary, 21 December 2012

In an attempt to understand why the Greek economy is collapsing, this Commentary points out two key aspects that are often overlooked – the country’s large multiplier and a bad export performance. When combined with the need for a large fiscal adjustment, these factors help explain how fiscal consolidation in Greece has been associated with such a large drop in GDP.

Integral group ring of the Suzuki sporadic simple group

Using the Luthar-Passi method, we investigate the classical Zassenhaus conjecture for the normalized unit group of the integral group ring of the Suzuki sporadic simple group Suz. As a consequence, for this group we confirm the Kimmerle`s conjecture on prime graphs.

Microwave-Assisted Derivatization of Cellulose in an Ionic Liquid: An Efficient, Expedient Synthesis of Simple and Mixed Carboxylic Esters

Microwave (MW)-assisted cellulose dissolution in ionic liquids (ILs) has routinely led either to incomplete biopolymer solubilization, or its degradation. We show that these problems can be avoided by use of low-energy MW heating, coupled with efficient stirring. Dissolution of microcrystalline cellulose in the IL 1-allyl-3-methylimidazolium chloride has been achieved without changing its degree of polymerization; regenerated cellulose showed pronounced changes in its index of crystallinity, surface area, and morphology. MW-assisted functionalization of MCC by ethanoic, propanoic, butanoic, pentanoic, and hexanoic anhydrides has been studied. Compared with conventional heating, MW irradiation has resulted in considerable decrease in dissolution and reaction times. The value of the degree of substitution (DS) was found to be DS(ethanoate) > DS(propanoate) > DS(butanoate). The values of DS(pentanoate) and DS(hexanoate) were found to be slightly higher than DS(ethanoate). This surprising dependence on the chain length of the acylating agent has been reported before, but not rationalized. On the basis of the rate constants and activation parameters of the hydrolysis of ethanoic, butanoic, and hexanoic anhydrides in aqueous acetonitrile (a model acyl transfer reaction), we suggest that this result may be attributed to the balance between two opposing effects, namely, steric crowding and (cooperative) hydrophobic interactions between the anhydride and the cellulosic surface, whose lipophilicity has increased, due to its partial acylation. Four ethanoate-based mixed esters were synthesized by the reaction with a mixture of the two anhydrides; the ethanoate moiety predominated in all products. The DS is reproducible and the IL is easily recycled. (C) 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 134-143, 2010

Partial economic reforrns and financial crises: an emerging markets perspective

The recent emerging market experiences have posed a challenge to the conventional wisdom that unsustainable fiscal deficits are the key to understanding financial crises in these countries. The health of the domestic banking system has emerged as the main driving force behind the perverse dynamics of partial reforms. The current paper shares this view and uses a model of contractual inefliciencies in the banking sector to understand the dynamics of these reforms. We find that the threat of a large exchange rate devaluation depends on the stock of international reserves relative to the stock of domestic credit that must be extended by the Central Bank in response to a large capital outflow. Moreover, if a country has a weak banking sector but high net reserve ratios, the capital flow reversal might only increase the vulnerability to a currency crisis without necessarily causing it. The results are in accordance with much of the empiricalliterature on the determinants of financiaI crises in emerging markets. Some aspectsof the recent policy debate on the introduction of capital controls are also analysed.

Scaling in the BCS to Bose crossover problem in different partial waves

The BCS superconductivity to Bose condensation crossover problem is studied in two dimensions in S, P, and D waves, for a simple anisotropic pairing, with a finite-range separable potential at zero temperature. The gap parameter and the chemical potential as a function of Cooper-pair binding B c exhibit universal scaling. In the BCS limit the results for coherence length ξ and the critical temperature T c are appropriate for highT c cuprate superconductors and also exhibit universal scaling as a function of B c.

Distortional buckling of simple lipped channel in bending results of the experimental analysis versus direct strength methods

Cold-formed steel members are subject to failure caused by buckling, normally under loads smaller than those corresponding to partial or total yielding of the cross section. The buckling of members in bending can be classified as local or global, and the occurrence of one or the other type is expected by the members' geometric characteristics and by the constraints and load conditions. One of the local instability modes that can characterize a member's failure is distortional buckling of the cross section occurring on its own plane and involving lateral displacements and rotations. This paper presents and discusses the procedures and results obtained from experimental tests of cold-formed steel members under bending. Forty-eight beams were carried out on members in simple lipped channel, in pairs, with 6-meter spans and loads applied by concentrated forces at every 1/3 of the span. The thickness, width and dimensions, of the stiffeners were chosen so that the instability by distortion buckling of the cross section was the principal failure mode expected. The experimental results are compared with the obtained results by using the direct strength method.

Preliminary Overview of the Economies of Latin America and the Caribbean 2007

Includes bibliography

Monetary dilemmas: Argentina in MERCOSUR

Includes bibliography

Social and economic problems in Cuba during the crisis and subsequent recovery

Includes bibliography

Inferring a weighted elastic network from partial unfolding with coarse-grained simulations

A number of studies have demonstrated that simple elastic network models can reproduce experimental B-factors, providing insights into the structure-function properties of proteins. Here, we report a study on how to improve an elastic network model and explore its performance by predicting the experimental B-factors. Elastic network models are built on the experimental C coordinates, and they only take the pairs of C atoms within a given cutoff distance r(c) into account. These models describe the interactions by elastic springs with the same force constant. We have developed a method based on numerical simulations with a simple coarse-grained force field, to attribute weights to these spring constants. This method considers the time that two C atoms remain connected in the network during partial unfolding, establishing a means of measuring the strength of each link. We examined two different coarse-grained force fields and explored the computation of these weights by unfolding the native structures. Proteins 2014; 82:119-129. (c) 2013 Wiley Periodicals, Inc.

Stochastic Partial Budgeting: A New Look at an Old Tool

Farm business managers are constantly making adjustments in their businesses for smoother operations and profitability. Many times, these choices involve actions to enhance the financial return of the farm business; while other times these decisions are made out of necessity to minimize the effects of unfavorable conditions or events such as drought or changes in the market conditions. Some of these decisions are relatively simple, requiring making choices among alternatives within an enterprise; while others are complex involving a total overhaul of the business and its enterprises. Alternative choices within an individual enterprise can have a differential impact on farm profitability. Therefore, making the best decision may make the difference between profit or loss for that enterprise. Partial budgeting is very useful in making such changes within an enterprise of a farm.