Transacciones, delegación o unilateralidad. Un análisis de los equilibrios de poder en las relaciones ejecutivo-legislativo durante los primeros gobiernos de Álvaro Uribe en Colombia y Carlos Saúl Menem en Argentina.

El presente trabajo analiza las relaciones entre poder ejecutivo y legislativo en los sistemas presidenciales, concentrándose específicamente en los casos de los primeros gobiernos de Álvaro Uribe Vélez en Colombia [2002-2006] y de Carlos Saúl Menem en Argentina [1989-1995]. Lo hace desde de una perspectiva analítica denominada neomadisoniana. Ubicada bajo el paraguas del neoinstitucionalismo, ésta utiliza como punto de partida el pensamiento de los padres fundadores de la democracia americana, particularmente el de James Madison, concentrándose en el estudio de como los arreglos institucionales constriñen el comportamiento de los actores a través del establecimiento de incentivos mediante los que se distribuyen distintos recursos de poder, proporcionando, además, una estructura estable, aunque no necesariamente eficiente, para la interacción humana. De este modo, el enfoque posee un particular interés por el análisis de la organización de los gobiernos, ya sea en términos de jerarquía o de transacciones entre actores instituciones [poderes ejecutivo y legislativo] que, de acuerdo al caso, gozan de distintos niveles de simetría y, consecuentemente, de capacidad de impactar sobre el proceso de toma de decisiones. Dentro de este marco, se intentarán identificar en el análisis de los casos patrones de regularidad y diferencia en relación a las características asumidas en el proceso de separación de poderes y el efecto que ejercen sobre él los poderes constitucionales y partidarios de los presidentes.

Modelli non lineari statici e dinamici su dati microeconomici: analisi delle condizioni finanziarie delle famiglie italiane

The thesis studies the economic and financial conditions of Italian households, by using microeconomic data of the Survey on Household Income and Wealth (SHIW) over the period 1998-2006. It develops along two lines of enquiry. First it studies the determinants of households holdings of assets and liabilities and estimates their correlation degree. After a review of the literature, it estimates two non-linear multivariate models on the interactions between assets and liabilities with repeated cross-sections. Second, it analyses households financial difficulties. It defines a quantitative measure of financial distress and tests, by means of non-linear dynamic probit models, whether the probability of experiencing financial difficulties is persistent over time. Chapter 1 provides a critical review of the theoretical and empirical literature on the estimation of assets and liabilities holdings, on their interactions and on households net wealth. The review stresses the fact that a large part of the literature explain households debt holdings as a function, among others, of net wealth, an assumption that runs into possible endogeneity problems. Chapter 2 defines two non-linear multivariate models to study the interactions between assets and liabilities held by Italian households. Estimation refers to a pooling of cross-sections of SHIW. The first model is a bivariate tobit that estimates factors affecting assets and liabilities and their degree of correlation with results coherent with theoretical expectations. To tackle the presence of non normality and heteroskedasticity in the error term, generating non consistent tobit estimators, semi-parametric estimates are provided that confirm the results of the tobit model. The second model is a quadrivariate probit on three different assets (safe, risky and real) and total liabilities; the results show the expected patterns of interdependence suggested by theoretical considerations. Chapter 3 reviews the methodologies for estimating non-linear dynamic panel data models, drawing attention to the problems to be dealt with to obtain consistent estimators. Specific attention is given to the initial condition problem raised by the inclusion of the lagged dependent variable in the set of explanatory variables. The advantage of using dynamic panel data models lies in the fact that they allow to simultaneously account for true state dependence, via the lagged variable, and unobserved heterogeneity via individual effects specification. Chapter 4 applies the models reviewed in Chapter 3 to analyse financial difficulties of Italian households, by using information on net wealth as provided in the panel component of the SHIW. The aim is to test whether households persistently experience financial difficulties over time. A thorough discussion is provided of the alternative approaches proposed by the literature (subjective/qualitative indicators versus quantitative indexes) to identify households in financial distress. Households in financial difficulties are identified as those holding amounts of net wealth lower than the value corresponding to the first quartile of net wealth distribution. Estimation is conducted via four different methods: the pooled probit model, the random effects probit model with exogenous initial conditions, the Heckman model and the recently developed Wooldridge model. Results obtained from all estimators accept the null hypothesis of true state dependence and show that, according with the literature, less sophisticated models, namely the pooled and exogenous models, over-estimate such persistence.