Weighted nucleoli and dually essential coalitions

We consider linearly weighted versions of the least core and the (pre)nucleolus and investigate the reduction possibilities in their computation. We slightly extend some well-known related results and establish their counterparts by using the dual game. Our main results imply, for example, that if the core of the game is not empty, all dually inessential coalitions (which can be weakly minorized by a partition in the dual game) can be ignored when we compute the per-capita least core and the per-capita (pre)nucleolus from the dual game. This could lead to the design of polynomial time algorithms for the per-capita (and other monotone nondecreasingly weighted versions of the) least core and the (pre)nucleolus in specific classes of balanced games with polynomial many dually esential coalitions.

Three Essays on the Economics of Defense Contracting, Output and Income Inequality

This dissertation analyzes both the economics of the defense contracting process and the impact of total dollar obligations on the economies of U.S. states. Using various econometric techniques, I will estimate relationships across individual contracts, state level output, and income inequality. I will achieve this primarily through the use of a dataset on individual contract obligations. The first essay will catalog the distribution of contracts and isolate aspects of the process that contribute to contract dollar obligations. Accordingly, this study describes several characteristics about individual defense contracts, from 1966-2006: (i) the distribution of contract dollar obligations is extremely rightward skewed, (ii) contracts are unevenly distributed in a geographic sense across the United States, (iii) increased duration of a contract by 10 percent is associated with an increase in costs by 4 percent, (iv) competition does not seem to affect dollar obligations in a substantial way, (v) contract pre-payment financing increases the obligation of contracts from anywhere from 62 to 380 percent over non-financed contracts. The second essay will turn to an aggregate focus, and look the impact of defense spending on state economic output. The analysis in chapter two attempts to estimate the state level fiscal multiplier, deploying Difference-in-Differences estimation as an attempt to filter out potential endogeneity bias. Interstate variation in procurement spending facilitates utilization of a natural experiment scenario, focusing on the spike in relative spending in 1982. The state level relative multiplier estimate here is 1.19, and captures the short run, impact effect of the 1982 spending spike. Finally I will look at the relationship between defense contracting and income inequality. Military spending has typically been observed to have a negative relationship with income inequality. The third chapter examines the existence of this relationship, combining data on defense procurement with data on income inequality at the state level, in a longitudinal analysis across the United States. While the estimates do not suggest a significant relationship exists for the income share of the top ten percent of households, there is a significant positive relationship for the income share of top one percent households for an increase in defense procurement.

Estimation of Sample Size and Power For Quantile Regression

Quantile regression (QR) was first introduced by Roger Koenker and Gilbert Bassett in 1978. It is robust to outliers which affect least squares estimator on a large scale in linear regression. Instead of modeling mean of the response, QR provides an alternative way to model the relationship between quantiles of the response and covariates. Therefore, QR can be widely used to solve problems in econometrics, environmental sciences and health sciences. Sample size is an important factor in the planning stage of experimental design and observational studies. In ordinary linear regression, sample size may be determined based on either precision analysis or power analysis with closed form formulas. There are also methods that calculate sample size based on precision analysis for QR like C.Jennen-Steinmetz and S.Wellek (2005). A method to estimate sample size for QR based on power analysis was proposed by Shao and Wang (2009). In this paper, a new method is proposed to calculate sample size based on power analysis under hypothesis test of covariate effects. Even though error distribution assumption is not necessary for QR analysis itself, researchers have to make assumptions of error distribution and covariate structure in the planning stage of a study to obtain a reasonable estimate of sample size. In this project, both parametric and nonparametric methods are provided to estimate error distribution. Since the method proposed can be implemented in R, user is able to choose either parametric distribution or nonparametric kernel density estimation for error distribution. User also needs to specify the covariate structure and effect size to carry out sample size and power calculation. The performance of the method proposed is further evaluated using numerical simulation. The results suggest that the sample sizes obtained from our method provide empirical powers that are closed to the nominal power level, for example, 80%.

Work Ethic, Social Ethic, no Ethic: Measuring the Economic Values of Modern Christians

Benito Arruñada finds evidence of a distinct Protestant social ethic in the ISSP’s 1998 Religion II Survey (Economic Journal 2010; 120: 890-918). We replicate Arruñada’s results using his broad definition of Protestantism and our new narrow definition, which includes only those ascetic denominations that Max Weber singled out for possessing a strong capitalist work ethic. We then extend this analysis to the ISSP’s 2008 Religion III Survey, the most recent comparable international questionnaire on religious attitudes and religious change. We find no evidence of a Calvinist work ethic, and suggest that Arruñada’s Protestant social ethic continues into the twenty-first century.

Human capital and the quantity–quality trade-off during the demographic transition

This paper provides an empirical test of the child quantity–quality (QQ) trade-off predicted by unified growth theory. Using individual census returns from the 1911 Irish census, we examine whether children who attended school were from smaller families—as predicted by a standard QQ model. To measure causal effects, we use a selection of models robust to endogeneity concerns which we validate for this application using an Empirical Monte Carlo analysis. Our results show that a child remaining in school between the ages of 14 and 16 caused up to a 27 % reduction in fertility. Our results are robust to alternative estimation techniques with different modeling assumptions, sample selection, and alternative definitions of fertility. These findings highlight the importance of the demographic transition as a mechanism which underpinned the expansion in human capital witnessed in Western economies during the twentieth century.

Neural networks would 'vote' according to Borda's Rule

Can neural networks learn to select an alternative based on a systematic aggregation of convicting individual preferences (i.e. a 'voting rule')? And if so, which voting rule best describes their behavior? We show that a prominent neural network can be trained to respect two fundamental principles of voting theory, the unanimity principle and the Pareto property. Building on this positive result, we train the neural network on profiles of ballots possessing a Condorcet winner, a unique Borda winner, and a unique plurality winner, respectively. We investigate which social outcome the trained neural network chooses, and find that among a number of popular voting rules its behavior mimics most closely the Borda rule. Indeed, the neural network chooses the Borda winner most often, no matter on which voting rule it was trained. Neural networks thus seem to give a surprisingly clear-cut answer to one of the most fundamental and controversial problems in voting theory: the determination of the most salient election method.

Technical appendix to Macrodynamics of economics: a bibliometric history

A history of specialties in economics since the late 1950s is constructed on the basis of a large corpus of documents from economics journals. The production of this history relies on a combination of algorithmic methods that avoid subjective assessments of the boundaries of specialties: bibliographic coupling, automated community detection in dynamic networks, and text mining. These methods uncover a structuring of economics around recognizable specialties with some significant changes over the period covered (1956–2014). Among our results, especially noteworthy are (1) the clear-cut existence of ten families of specialties, (2) the disappearance in the late 1970s of a specialty focused on general economic theory, (3) the dispersal of the econometrics-centered specialty in the early 1990s and the ensuing importance of specific econometric methods for the identity of many specialties since the 1990s, and (4) the low level of specialization of individual economists throughout the period in contrast to physicists as early as the late 1960s.

William Stanley Jevons : el uso de las probabilidades y el cálculo

En el capítulo tercero de la TPE, Jevons recurre al uso de las probabilidades como un método alternativo para analizar el intercambio de las mercancías. Jevons, decide no continuar con el uso de las probabilidades en los capítulos siguientes; su teoría se bifurca imperando el uso del cálculo diferencial. La explicaciónde esta bifurcación radica en la existencia de dos métodos alternativos para explicar el análisis del intercambio: La teoría de las probabilidades y el cálculo diferencial. Usar el cálculo diferencial no significaba que fuese el método más eficiente, pues no sólo existieron errores al maximizar como muestra Westergaard(1874), sino también problemas metodológicos, como muestranStigler (1956) y Blaug (1985). Por otro lado, el método de las probabilidades habría significado para el análisis del intercambio, un problema de valores esperados y un camino totalmente diferente para la revolución marginalista.

¿El consenso sobre la racionalidad económica?

Este artículo examina la robustez que sostiene el núcleo teórico ortodoxo, más específicamente, los supuestos de información y racionalidad perfectas. Se hace alusión a un modelo de toma de decisiones bajo racionalidad acotada y perfecta información comoalternativa teórica.

El papel de los costes de transacción en la formación de convenciones

Este ensayo discute la convención a partir de la dinámica de réplica. La coordinación surge a través del concepto de eficiencia explicando por qué los costes de transacción son fundamentalesen las decisiones de los agentes. Cuando los agentes siguendinámicas de réplica existe una serie de reglas «heredadas» que proveen la experiencia que los jugadores necesitan para alcanzar la coordinación. De esta forma la convención será una estrategia evolutivamente estable.

Análisis de la gestión ambiental integral de las empresas grandes del Valle del Cauca

El trabajo de investigación realizado por los profesores Juan Antonio Gudziol y Andrés López de la Universidad ICESI pretende poner a disposición de los gerentes de las empresas grandes del Valle del Cauca, una serie de herramientas que les permitirán en el futuro evaluar su posición competitiva en el ámbito mundial en lo relativo a la Gestión Ambiental Integral. Los resultados de dichasevaluaciones periódicas servirán de guía para una mejor utilización de los recursos con que cuenta el país y en especial el departamento del Valle del Cauca. Los resultados obtenidos en esta investigación son el punto de partida para evaluaciones futuras y reenfoques necesarios para mantener los niveles de competitividad de las industrias que utilicen este método propuesto.

Crisis de la deuda en las Empresas Municipales de Cali y perspectivas

Emcali es una Empresa Industrial y Comercial del Estado, la principal entidad descentralizada del municipio de Cali; actualmente, y desde abril de 2000, se encuentra intervenidapor la Superintendencia de Servicios Públicos Domiciliarios, por locual debe resolver antes de abril del año 2002 los problemas financieros que amenazan la viabilidad en su actividad económica, consistente en la prestación de los servicios de acueducto, alcantarillado, energía y telecomunicaciones.No es objetivo de este trabajo constituirse en la carta de salvación para la empresa, pues esta es una tarea que le corresponde a los asesores contratados por el Gobierno para tal fin; se trata más bien de un aporte desde el punto de vistaacadémico para llamar la atención sobre los hechos que desencadenaron la crisis y así evitar futuras situacionessimilares. Sin embargo, al final se exponen algunas recomendaciones que consideramos podrían tomarse encuenta para llegar a una solución.

Características socioeconómicas y consistencia en la toma de decisiones

Este ensayo analiza cuál es el efectode las características socioeconómicassobre la consistencia en las preferenciascuando los agentes se encuentraneligiendo entre loterías. Elanálisis parte de realizar la pruebade ALLAIS, sobre la consistencia en laselecciones, a los estudiantes de lacarrera de Economía y Negocios Internacionalesde la Universidad Icesiy, se encuentra que el sexo, el estratosocioeconómico, el ingreso, laedad y el semestre en forma conjuntano son relevantes para explicar laconsistencia en las preferencias. Sinembargo, también se observa que laedad y el semestre podrían ayudar aexplicar la consistencia.

¿Es posible explorar nuevas alternativas para la formación de creencias en la decisión de invertir en capital humano?

Es imposible negar el sentimiento de fastidio por parte de uno que otro economista frente a la teoría clásica. Fastidio que nace cuando insistentemente se compara el supuesto de racionalidadperfecta y la manera como el ser humano en realidad se comporta. Pero, no sólo ha sido la insatisfacción de muchos economistas frente a dicha construcción teórica, sino tambiénlos intentos por reemplazar el modelo básico del hombre racional,los que han hecho que surjan una serie de propuestas para modelar el problema de la toma de decisiones de una manera diferente. Así como muchos han expresado su disconformidad,este artículo tendrá como propósito hacer lo mismo. Es decir, intentará explorar una nueva alternativa para entender cómo y por qué los agentes toman la decisión de invertir en capital humano.

Evaluación de la aplicación de dos modelos de valoración de opciones a la administración de portafolios

El artículo revisa la teoría de opciones y propone un método para la implementación del «Portfolio Insurance » basado en el modelo binomial, el cual es evaluado en oposición al modelo de Black-Scholes. Usando datos reales y simulados se encuentra que el método de Black-Scholes se desempeña mejor en condiciones «inestables »; el modelo binomial, en cambio,obtiene mejores resultados con tendencias definidas en los precios de las acciones (crecientes, decrecientes o estables durante un período extendido).