This Ph.D. thesis comprises of two parts. Part I develops a framework to provide insights into the understanding of several political macro-economy issues related to fiscal policy making. This framework links the overall macroeconomic performance to the public spending and borrowing decisions. The key feature of this framework is that it makes a distinction between productive (e.g. public investment) and non-productive public spending (e.g. popular spending). It is shown that a high level of political instability may lead to myopic and populist policies and may be associated with less favorable macroeconomic performance in terms of not only future output and inflation but also future popular spending. Part I also suggests an alternative channel for expansionary or Non-Keynesian fiscal contractions based on the productivity enhancing role of productive public spending. It is shown that if the incumbent government reduces popular (productive) spending rather than productive (popular) spending, then Non-Keynesian (Keynesian) effects are achieved. Furthermore, it is shown that the favorable effects of public investment depends positively on its quality in this framework. Moreover, the net effect of productive spending financed by borrowing on the next period&#039 / s macroeconomic performance depends on the benefits of productive spending relative to the costs of borrowing. Even under a capital borrowing rule higher public investment may yield unfavorable effects and also it may not necessarily prevent the strategic use of public investment, even though it prevents strategic debt accumulation. Part II investigates the effects of macroeconomic instability on capital accumulation and economic growth in the Turkish economy over the 1963-1999 period. Descriptive and econometric (time series) analyses suggest that macroeconomic instability not only deters capital accumulation and economic growth but it may also reverse the complementarity between public and private investment in the long-run.

Notre étude a été inspirée par l’observation que malgré les efforts considérables en matière de la libéralisation financière au Malawi à partir de la fin des années 1980, les résultats apparents étaient plutôt médiocres, notamment en ce qui concerne la persistance de marges d’intermédiation (spreads) élevés. L’objectif central de notre travail est d’essayer d’élucider pourquoi. Notre hypothèse centrale est que si l’on ne tient pas compte du comportement des banques en matière de leurs réactions vis-à-vis de leurs incitations et leurs contraintes dans la mise en place de la politique de la libéralisation financière, on est voué à la déception en matière des résultats. L’étude montre que dans une situation économique caractérisée par une instabilité macroéconomique, les banques ont moins d’incitations à être plus efficientes du point de vue macroéconomique, c’est à dire en agissant dans la direction de l’approfondissement financier et de l’octroi de crédit au secteur privé. Bien au contraire, tout en agissant de manière rationnelle, elles sont tentées de rechercher des rentes faciles et sûres qui viennent du financement des déficits publics. Ceci leur permet d’accomplir deux objectifs : maximiser leur profit et minimiser leur risque-crédit, notamment en repoussant les « contraintes externes » imposées par les conditions économiques -notamment les taux d’escompte élevées- à leur clients à travers la combinaison d’une augmentation de taux d'intérêt sur les prêts et d’une faible augmentation des taux d'intérêt sur les dépôts. / This study was inspired by the observation that despite the considerable efforts in financialliberalization in Malawi from the late 1980s, the apparent results were mediocre, especially with regardto the persistence of high intermediation margins (spreads). The central objective of this study is to tryto investigate why. The key hypothesis is that if one does not take into account of bank behavior interms of how banks react vis-à-vis their incentives and constraints during the process of financialliberalization, the results are likely to be disappointing. The study shows that in an economic situationcharacterized by macroeconomic instability, banks have less incentive to be more efficient from amacroeconomic perspective, i.e., by enhancing financial deepening through higher credit to the privatesector. On the contrary, while acting rationally, they are tempted to look for easy and safe returnscoming from financing government deficits. This allows them to accomplish two objectives: maximizingprofit and minimizing credit risk, notably by pushing the "external constraints" imposed by economicconditions - including high rediscount rates- to their customers through a combination of an increasein interest rates on loans and a smaller increase in interest rates on deposits.Keywords: financial liberalization, bank behavior, intermediation margins, bank