E’ stato estesamente appurato che i mercati dell'elettricità mostrano mean-reversion e elevata volatilità dei prezzi. Questo lavoro utilizza un modello VAR-MGARCH al fine di cogliere queste caratteristiche presenti sul mercato dell'energia elettrica italiana (IPEX) e analizzare le interrelazioni esistenti tra le diverse regioni in cui il mercato è suddiviso. L’analisi è condotta sui prezzi giornalieri dal 1 ° gennaio 2006 al 31 dicembre 2008. I coefficienti stimati dalle equazioni condizionali indicano che i mercati regionali sono abbastanza integrati e i prezzi regionali dell'energia elettrica possono essere adeguatamente previsti impiegando i prezzi passati di ciascun mercato zonale. La volatilità e la cross-volatility sono significative per tutti i mercati, indicando la presenza di forti componenti ARCH e GARCH e la sostanziale inefficienza dei mercati. E’ inoltre evidente un’elevata persistenza della volatilità e della cross-volatility in tutti i mercati. I risultati indicano inoltre che gli shock rilevati, sia nella volatilità, sia nei vari mercati, persistono nel tempo e che in ogni mercato la persistenza è più marcata quando è causata da innovazioni stimate sulle stesso mercato rispetto a shock stimati su altre aree. Questa persistenza descrive la tendenza delle variazioni dei prezzi a raggrupparsi nel tempo. / It is commonly known that spot electricity markets show mean-reversion and high price volatility. This work employs a VAR-MGARCH model to capture these features in the Italian electricity market (IPEX) and analyze the interrelation existing among the different regions in which the market is divided. Daily spot prices from 1 January 2006 to 31 December 2008 are employed. The estimated coefficients from the conditional mean equations indicate that the regional markets are quite integrated and regional electricity prices could be usefully forecasted using lagged prices from either the same market or from the other areal markets. Volatility and cross-volatility spill-overs are significant for all markets, indicating the presence of strong ARCH and GARCH effects and market inefficiency. Strong persistence of volatility and cross-volatility are also evident in all local markets. The results also indicate that volatility innovations or shocks in all markets persist over time and that in every market this persistence is more marked for own-innovations or shocks than cross-innovations or shocks. This persistence captures the propensity of price changes of similar magnitude to cluster in time.

This thesis consists of four self-contained essays on the various topics in finance.  The first essay, The Information Content of The Systematic Risk Structure of Corporate Yields for Future Real Activity: An Exploratory Empirical Investigation, constructs a proxy for the systematic component of the risk structure of corporate yields (or systematic risk structure), and tests how well it predicts real economic activity in the United States. It finds that the systematic risk structure predicts the growth rate of industrial production 3 to 18 months into the future even when other leading indicators are controlled for, outperforming other models. A regime-switching estimation also shows that the systematic risk structure is very successful in identifying and capturing different growth regimes of industrial production.  The second essay, How Much Leverage is Too Much, or Does Corporate Risk Determine the Severity of a Recession? investigates whether financial conditions of the U.S. corporate sector  can explain the probability and severity of recessions. It proposes a measure of corporate vulnerability, the Corporate Vulnerability Index (CVI) constructed as the default probability for the entire corporate sector. It finds that the CVI is a significant predictor of the probability of a recession 4 to 6 quarters ahead, even controlling for other leading indicators, and that an increase in the CVI is also associated with a rise in the probability of a more severe and lengthy recession 3 to 6 quarters ahead.  The third essay, Asian Flu or Wall Street Virus? Tech and Non-Tech Spillovers in the United States and Asia (with Jorge A. Chan-Lau), using TGARCH models, finds that U.S. stock markets have been the major source of price and volatility spillovers to stock markets in the Asia-Pacific region during three different periods: the pre-LTCM crisis period, the “tech bubble” period, and the “stock market correction” period. Hong Kong SAR, Japan, and Singapore were sources of spillovers within the region and affected the United States during the latter period. There is also evidence of structural breaks in the stock price and volatility dynamics induced during the “tech bubble” period.  The fourth essay, Coping with Financial Spillovers from the United States: The Effect of U. S. Corporate Scandals on Canadian Stock Prices, investigates the effect of U.S. corporate scandals on stock prices of Canadian firms interlisted  in the United States. It finds that firms interlisted during the pre-Enron period enjoyed increases in post-listing equilibrium prices, while firms interlisted during the post-Enron period experienced declines in post-listing equilibrium prices, relative to a model-based benchmark. Analyzing the entire universe of Canadian firms, it finds that interlisted firms, regardless of their listing time, were perceived as increasingly risky by Canadian investors after the Enron’s bankruptcy. / Diss. Stockholm : Handelshögskolan, 2003

Cette thèse analyse les enjeux du développement économique liés aux dynamiques des cours des matières premières en général et ceux du coton en particulier. Traditionnellement, les travaux s’inscrivant dans une optique de long terme questionnent la pertinence des spécialisations primaires des PMA. À moyen terme l’intérêt porte davantage sur l’instabilité dont les conséquences sont d’autant plus importantes que la dépendance des pays à l’exportation de tels produits est forte. Les enjeux s’articulent alors autour des modalités de régulation des marchés, du choix d'outils (publics ou marchands) pour la gestion des incertitudes, le tout dépendant de l’appréhension de l’instabilité comme un phénomène endogène ou exogène. Dans un contexte nouveau marqué par l’affirmation d’oligopoles de firmes, la segmentation du processus productif mondial, et la financiarisation des marchés de matières premières, nous proposons un cadre analytique permettant d’aborder différemment ces problématiques. Nos travaux montrent d’abord comment les approches du type chaînes globales de valeur peuvent être mobilisées pour mieux orienter les stratégies commerciales / industrielles des PMA. S’appuyant sur la notion de rationalité limitée dans le cadre de modèles de comportements hétérogènes, ils prouvent ensuite l’existence d’une forte composante endogène dans l’instabilité et par là même, l'inefficacité des seuls outils marchands. Au final, pour les pays africains producteurs de coton, il apparait qu’il reste possible de mettre ce produit au service d’une stratégie globale de développement. Cela passe par le recours à des mécanismes hybrides de gestion de l’instabilité, combiné au renforcement des dynamiques de coopération transfrontalières en vue d’une structuration de chaînes régionales de valeur. / This thesis analyzes the economic development issues related to the medium and long-term dynamics of commodities prices in general and cotton prices in particular. Studies on the long-term perspective traditionally question the relevance of primary specializations of LDCs. In the medium term, the interest is relates to price instability for which the consequences are all the more important as countries’ dependency on the exports of such products becomes stronger. The stakes then revolve around market regulation modalities, and the choice of risk management tools (e.g. public or private interventions). These depend on the apprehension of price fluctuations as a phenomenon arising from endogenous or exogenous market factors. In a new economical context influenced by the growing importance of oligopolistic firms, a segmentation of the productive process and the financialization of commodity markets, we address differently these issues through a new analytical framework. The proposed analysis first shows how approaches such as the ones related to global value chains are more adapted to tackle industrial/commercial policies in commodity dependent LDCs. Second, in a context of heterogeneous behavioral models, we rely on the concept of bounded rationality to show the presence of a strong endogenous component in instability. Thus, it proves the inefficiency of private interventions to counter instability. Considering these findings in the case of African cotton producers, we conclude that it remains possible to incorporate the commodity in a global development strategy. But this involves the use of hybrid-type mechanisms (public-private) for managing uncertainty, combined with a reinforcement of cross-border cooperation dynamics in order to structure regional value chains.