This dissertation is divided into four essays, each of them having its own structure and methodological framework. Although each of the essays making the chapters of the thesis is self-contained, their topics are very closely related. Consequently, the reader will be able to follow the thesis in its unity. The four essays are empirical and address some relevant issues from monetary economics and policy. In first three essays we aim at the way central banks sets their policy rates, which is usually described by central bank’s reaction function or a monetary policy rule (Taylor, 1993), and in the fourth one, we look at the inflation dynamics and the New Keynesian (NK) Phillips Curve (Galí and Gertler, 1999). In the first three papers, we look at different issues related to policy rules such as their nonlinearities, evolution across time, the intensity of interest rate response to inflation, degree of policy inertia as well as how policy changes when it is faced by financial stress. The monetary policy rule and the NK Phillips Curve became key elements of the NK policy model (e.g. Galí, 2008), which is at present the most influential theoretic framework for analysis of macroeconomic dynamics and monetary policy both in academia and among monetary policy makers. Dynamics Stochastic General Equlibrium models (DSGE), which are the main analytic tools within most central banks (e.g. Area-Wide model of the European Central Bank), are inspired by the NK models. While the traditional Keynesian literature assumed sticky prices and wages in the short-term, it was unable to provide their satisfactory microeconomic explanations. The NK model enriched the original Keynesian literature by microeconomic foundations but at the same time by some important elements such as rational expectations and vertical long-term Phillips curve incompatible with the Keynesian tradition. Price rigidities (both nominal and real), which are result of imperfect competition, enable that monetary policy has impact on real variables in the short term. Such view on monetary policy is quite paradoxically close to monetarism but quite distant from other current macroeconomic branches such as Real Business Cycle Theory or Post-Keynesianism that cast doubt on the ability of monetary policy to affect real economy (Snowdon and Vane, 2005). In spite of the popularity of NK models, the empirical evidence goes behind the theory. The purpose of this thesis is to contribute to the empirics of the NK model.

This thesis investigates different social and political aspects of modern economies. The first chapter contributes to the natural resource curse debate, by showing that the impact of resource windfalls is different among democracies and autocracies. The results also point to the existence of a large heterogeneity in the response to resource shocks among autocracies. The second chapter focuses on metropolitan areas in the US, and deals with the issue of social capital formation. I examine one important aspect of social capital, trust, and argue that it is lower when income inequality between different racial groups in the metropolitan area is higher. The third chapter studies the relation between media influence and electoral voting in Italy. I relate electoral outcomes at the municipal level to differences in signal reception of Silvio Berlusconi's private TV network. The results show that greater exposure to commercial television increases support for Silvio Berlusconi's party. / Aquesta tesi investiga diferents aspectes socials i polítics de les economies modernes. El primer capítol versa sobre el debat a l'entorn dels recursos naturals, mostrant que l'impacte dels guanys imprevistos dels recursos és diferent entre democràcies i autocràcies. Els resultats també indiquen l'existència d'una àmplia heterogeneïtat entre autocràcies en la seva reacció davant a variacions dels recursos. El segon capítol se centra en les àrees metropolitanes dels EUA i tracta el tema de la formació de capital social. He examinat un aspecte important del capital social, la confiança, i, argumento que és baixa quan, en la mateixa zona metropolitana, hi ha una gran desigualtat en les rentes dels diferents grups racials. El tercer capítol estudia la relació entre la influència dels mitjans de comunicació i el vot electoral a Itàlia. He relacionat els resultats electorals a nivell municipal amb les diferències en la recepció del senyal dels canals privats de televisió de Silvio Berlusconi. El resultat mostra que una gran exposició a la televisió comercial incrementa el suport polític al partit de Berlusconi.