Gouvernée par un socle juridique d’inspiration religieuse, le fonctionnement de la banque islamique est, sur le plan théorique, différent de celui de la banque conventionnelle. Bien que la littérature portant sur les mécanismes de transmission de la politique monétaire dans un cadre conventionnel soit abondante, rares sont les travaux, théoriques et empiriques, qui examinent le rôle des banques islamiques dans cette transmission. En effet, la littérature existante ne présente pas de schéma analytique complet permettant d’appréhender clairement le rôle des banques islamiques dans la transmission de la politique monétaire, et d'identifier et spécifier la nature des interactions entre banques islamiques et banques conventionnelles. L’ambition de la présente thèse, structurée en trois chapitres, consiste donc à étudier par quels mécanismes et dans quelles mesures la banque centrale est susceptible de réguler l’activité économique en présence de banques islamiques. / Governed by a religiously inspired legal framework, Islamic banking is, in theory, different from conventional banking. While the literature on the transmission mechanisms of monetary policy in a conventional framework is abundant, very little research, theoretical and empirical, has been focused directly at the role of Islamic banks in this transmission. Indeed, the existing literature does not present a complete analytical framework allowing a full and clear understanding of the role of Islamic banks in the transmission of monetary policy, and to identify and specify the nature of the interactions between Islamic and conventional banks. The aim of this thesis, made up of three chapters, is to study by which mechanisms and to what extent the central bank is likely to regulate the economic activity in the presence of Islamic banks.

Ma thèse étudie la pensée monétaire ainsi que les travaux de Ralph G. Hawtrey, Harry D. White et Robert Triffin, entre 1919 et 1960. Au cours des débats sur cette période, considérée comme fondatrice pour le système monétaire international, ces trois économistes ont été des personnalités clés qui ont influencé le cours de l’histoire monétaire. Premièrement, ils ont critiqué la théorie de l’étalon-or issue de la tradition ricardienne, en soulignant le caractère non-automatique et asymétrique du mécanisme d’ajustement de la balance des paiements. En s’articulant autour du rejet de cette tradition, les analyses de nos auteurs ont caractérisé les faiblesses liées au fonctionnement du système monétaire international. Deuxièmement, bénéficiant de leurs positions au Trésor américain et britannique, au FMI ou encore à la Fed, ces économistes ont exercé une influence sur les réformes en œuvrant pour une consolidation de la coopération monétaire internationale dans un régime de changes fixes. / My PhD dissertation studies Ralph G. Hawtrey’s, Harry D. White’s and Robert Triffin’s monetary thought and works between 1919 and 1960. Actively participating to key institutions which shaped the international monetary system – the British Treasury for Hawtrey, the US Treasury for White and the Fed and the IMF in the case of Triffin – those economists influenced the course of monetary theory and history. They both wrote on the non-automatic and asymmetric nature of the balance of payments adjustment mechanism, and formulated an original critic towards the classical Ricardian gold standard theory. Structured around the rejection of this classical theory, the authors’ analysis pointed out the weaknesses of the international monetary system. Since then, all of their reform proposals were grounded on the strengthening of monetary cooperation under a fixed exchange rates system.

Les fluctuations économiques représentent les mouvements de la croissance économique. Celle-ci peut connaître des phases d'accélération (expansion) ou de ralentissement (récession), voire même de dépression si la baisse de production est persistente. Les fluctuations économiques sont liées aux écarts entre croissance effective et croissance potentielle. Elles peuvent s'expliquer par des chocs d'offre et demande, ainsi que par le cycle du crédit. Dans le premier cas, les conditions de la production se trouvent modifiées. C'est le cas lorsque le prix des facteurs de production (salaires, prix des matières premières) ou que des facteurs externes influençant le prix des produits (taux de change) évolue. Ainsi, une hausse du prix des facteurs de production provoque un choc négatif et ralentit la croissance. Ce ralentissement peut être également dû à un choc de demande négatif provoqué par une hausse du prix des produits causée par une appréciation de la devise, engendrant une diminution des exportations. Le deuxième cas concerne les variables financières et les actifs financiers. Ainsi, en période d'expansion, les agents économiques s'endettent et ont des comportements spéculatifs en réaction à des chocs d'offre ou demande anticipés. La valeur des titres et actifs financiers augmente, provoquant une bulle qui finit par éclater et provoquer un effondrement de la valeur des biens. Dès lors, l'activité économique ne peut plus être financée. C'est ce qui génère une récession, parfois profonde, comme lors de la récente crise financière. Cette thèse inclut trois essais sur les fluctuations macroéconomiques et les cycles économiques, plus précisément sur les thèmes décrit ci-dessus. Le premier chapitre s'intéresse aux anticipations sur la politique monétaire et sur la réaction des agents écononomiques face à ces anticipations. Une emphase particulière est mise sur la consommation de biens durables et l'endettement relié à ce type de consommation. Le deuxième chapitre aborde la question de l'influence des variations du taux de change sur la demande de travail dans le secteur manufacturier canadien. Finalement, le troisième chapitre s'intéresse aux retombées économiques, parfois négatives, du marché immobilier sur la consommation des ménages et aux répercussions sur le prix des actifs immobiliers et sur l'endettement des ménages d'anticipations infondées sur la demande dans le marché immobilier. Le premier chapitre, intitulé ``Monetary Policy News Shocks and Durable Consumption'', fournit une étude sur le lien entre les dépenses en biens durables et les chocs monétaires anticipés. Nous proposons et mettons en oeuvre une nouvelle approche pour identifier les chocs anticipés (nouvelles) de politique monétaire, en les identifiant de manière récursive à partir des résidus d’une règle de Taylor estimée à l’aide de données de sondage multi-horizon. Nous utilisons ensuite les chocs anticipés inférer dans un modèle autorégressif vectoriel structurel (ARVS). L’anticipation d’une politique de resserrement monétaire mène à une augmentation de la production, de la consommation de biens non-durables et durables, ainsi qu’à une augmentation du prix réel des biens durables. Bien que les chocs anticipés expliquent une part significative des variations de la production et de la consommation, leur impact est moindre que celui des chocs non-anticipés sur les fluctuations économiques. Finalement, nous menons une analyse théorique avec un modèle d’équilibre général dynamique stochastique (EGDS) avec biens durables et rigidités nominales. Les résultats indiquent que le modèle avec les prix des biens durables rigides peut reproduire la corrélation positive entre les fonctions de réponse de la consommation de biens non-durables et durables à un choc anticipé de politique monétaire trouvées à l’aide du ARVS. Le second chapitre s'intitule ``Exchange Rate Fluctuations and Labour Market Adjustments in Canadian Manufacturing Industries''. Dans ce chapitre, nous évaluons la sensibilité de l'emploi et des heures travaillées dans les industries manufacturières canadiennes aux variations du taux de change. L’analyse est basée sur un modèle dynamique de demande de travail et utilise l’approche en deux étapes pour l'estimation des relations de cointégration en données de panel. Nos données sont prises d’un panel de 20 industries manufacturières, provenant de la base de données KLEMS de Statistique Canada, et couvrent une longue période qui inclut deux cycles complets d’appréciation-dépréciation de la valeur du dollar canadien. Les effets nets de l'appréciation du dollar canadien se sont avérés statistiquement et économiquement significatifs et négatifs pour l'emploi et les heures travaillées, et ses effets sont plus prononcés dans les industries davantage exposées au commerce international. Finalement, le dernier chapitre s'intitule ``Housing Market Dynamics and Macroprudential Policy'', dans lequel nous étudions la relation statistique suggérant un lien collatéral entre le marché immobilier and le reste de l'économique et si ce lien est davantage entraîné par des facteurs de demandes ou d'offres. Nous suivons également la littérature sur les chocs anticipés et examinons un cyle d'expansion-récession peut survenir de façon endogène la suite d'anticipations non-réalisées d'une hausse de la demande de logements. À cette fin, nous construisons un modèle néo-Keynésien au sein duquel le pouvoir d’emprunt du partie des consommateurs est limité par la valeur de leur patrimoine immobilier. Nous estimons le modèle en utilisant une méthode Bayésienne avec des données canadiennes. Nous évaluons la capacité du modèle à capter les caractéristiques principales de la consommation et du prix des maisons. Finalement, nous effectuons une analyse pour déterminer dans quelle mesure l'introduction d'un ratio prêt-à-la-valeur contracyclique peut réduire l'endettement des ménages et les fluctuations du prix des maisons comparativement à une règle de politique monétaire répondant à l'inflation du prix des maisons. Nous trouvons une relation statistique suggérant un important lien collatéral entre le marché immobilier et le reste de l'économie, et ce lien s'explique principalement par des facteurs de demande. Nous constatons également que l'introduction de chocs anticipés peut générer un cycle d'expansion-récession du marché immobilier, la récession faisant suite aux attentes non-réalisées par rapport à la demande de logements. Enfin, notre étude suggère également qu'un ratio contracyclique de prêt-à-la-valeur est une politique utile pour réduire les retombées du marché du logement sur la consommation par l'intermédiaire de la valeur garantie. / Economic fluctuations represent the movements of economic growth. It may experience acceleration phases (expansion) or deceleration (recession), and even depression if the decline in production is persistent. Economic fluctuations are related to differences between actual growth and potential growth. They can be explained by supply and demand shocks, as well as by the credit cycle. In the first case, the conditions of production are modified. This is the case when the price of production factors (wages, raw materials prices) or external factors influencing the price of products (exchange rate) evolve. Thus, an increase in the price of production factors causes a negative shock and slows growth. This slowdown may also be due to a negative demand shock caused by an increase in product prices caused by a currency appreciation, causing a decrease in exports. The second case concerns the financial variables and financial assets. Thus, in a period of expansion, economic agents borrow more and have speculative behaviors in response to anticipated supply and demand shocks. The value of securities and financial assets increases, causing a bubble that eventually burst, causing a collapse in the value of assets. Therefore, economic activity cannot be funded. This is what generates a recession, sometimes profound, as in the recent financial crisis. This thesis includes three essays on macroeconomic fluctuations and economic cycles, specifically on the topics described above. The first chapter deals with expectations about monetary policy and on the reaction of econonomic agents on these expectations. A particular emphasis is placed on the consumption of durable goods and indebtedness related to this type of consumption. The second chapter discusses the influence of fluctuations in foreign exchange rates on labour demand in the Canadian manufacturing sector. Finally, the third chapter focuses on spillover, sometimes negative, of the real estate market on household consumption and the impact on property prices and household debt of demand expectations in the property market. The first chapter, entitled ``Monetary Policy News Shocks and Durable Consumption'', provides insight on the link between durable goods spending and monetary policy news shocks. We propose and implement a new approach to identifying news shocks about future monetary policy. News shocks are identified recursively from the residuals of a monetary policy rule estimated using U.S. multi-horizon survey data. We then use those inferred news shocks in a structural VAR (SVAR). An expected monetary policy tightening leads to an increase in output, non-durable and durable goods consumption, and real price of durable goods. Although news shocks account for a significant fraction of output and consumption fluctuations, they contribute less than surprise shocks to economic fluctuations. We then carry out theoretical analysis using a dynamic stochastic general equilibrium (DSGE) model with durable goods and nominal rigidities. Results indicate that a model with sticky durable goods price can reproduce the positive correlation between the response functions of durable and non-durable goods consumption to policy news shocks that was found from the SVAR. The second chapter is entitled ``Exchange Rate Fluctuations and Labour Market Adjustments in Canadian Manufacturing Industries''. In this chapter, we estimate the impact of exchange rate fluctuations on hours worked and jobs in Canadian manufacturing industries. The analysis is based on a dynamic model of labour demand and the econometric strategy employs a panel two-step approach for cointegrating regressions. Our data is drawn from a panel of 20 manufacturing industries, from Statistics Canada's KLEMS database, and covers a long sample period that includes two full exchange rate appreciation and depreciation cycles. We find that exchange rate fluctuations have economically and statistically significant effects on the labour decisions of Canadian manufacturing employers, and that these effects are stronger for trade-oriented industries. Finally, the last chapter, entitled ``Housing Market Dynamics and Macroprudential Policy'', studies the statistical evidence suggesting a collateral link between the housing market and the rest of the economy and if the link is more demand- or supply-driven. We also followed the \textit{news shocks} literature and look if a housing-market boom-bust can arise endogenously following unrealized expectations of a rise in housing demand. To this end, we construct a New Keynesian model in which a fraction of households borrow against the value of their houses. We estimate the model with Canadian data using Bayesian methods. We assessed the model's ability to capture key features of consumption and house price data. Finally, we performed an analysis to determine how well the introduction of a countercyclical loan-to-value (LTV) ratio can reduced household indebtedness and housing price fluctuations compare to a monetary policy rule augmented with house price inflation. We find statistical evidence suggesting an important collateral link between the housing market and the rest of the economy, and this link is mainly driven by demand factors. We also find that the introduction of news shocks can generate a housing market boom-bust cycle, the bust following unrealized expectations on housing demand. Finally, our study also suggests that a countercyclical loan-to-value ratio is a useful policy to reduce the spillover from housing market to consumption via the collateral value.

Cette thèse analyse le rôle de l’apprentissage dans deux cadres de modélisation distincts. Dans le cas dunouveau modèle canonique avec apprentissage adaptatif, les caractéristiques les plus marquantes des dynamiquesd’apprentissage concernent la capacité des règles de politique monétaire à assurer la convergencevers l’équilibre en anticipations rationnelles. Le mécanisme de transmission de la politique monétaire estcelui de l’effet de substitution associé au canal de la consommation. Dans le cas d’un modèle multi-agentsqui relâche des hypothèses restrictives du nouveau modèle canonique, tout en restant structurellementproche de celui-ci, les variables agrégées évoluent à bonne distance de cet équilibre, et on observe desdynamiques nettement différentes. La politique monétaire influence les variables agrégées de manièremarginale via l’effet de revenu du canal de la consommation. En présence d’un processus d’apprentissagesocial évolutionnaire, l’économie converge vers un faible niveau d’activité économique. L’introductiond’un processus caractérisé par le fait que les agents apprennent individuellement à l’aide de leurs modèlesmentaux atténue le caractère dépressif des dynamiques d’apprentissage. Ces différences entre les deuxcadres de modélisation démontrent la difficulté de généraliser les résultats du nouveau modèle canonique. / This thesis analyses the role of learning in two different modelling frameworks. In the new canonicalmodel with adaptive learning, the most remarkable characteristics of the learning dynamics deal withthe capacity of monetary policy rules to guaranty convergence to the rational expectations equilibrium.The transmission mechanism of the monetary policy is based on the substitution effect associated to theconsumption channel. In the case of an agent-based model which relaxes some restrictive assumptionsof the new canonical model - but is endowed with a similar structure - aggregate variables evolve atsome distance from the rational expectations equilibrium. Monetary policy has a marginal impact onthe agregated variables via the wealth effect of the consumption channel. When agents learn accordingto an evolutionnary social learning process, the economy converges to regions of low economic activity.The introduction of a process where agents learn individually by using their mental models induces lessdepressive learning dynamics. These differences between the two modelling frameworks show that thegeneralisation of the results of the new canonical model is not easy to achieve.

Avec l’annonce de la création d’une Union bancaire européenne, l’évolution du cadre institutionnel de la régulation prudentielle est actuellement au coeur des débats politiques. Le projet de réforme prévoit la dévolution d’une importante partie du contrôle prudentiel des entreprises financières à la Banque centrale européenne. Les conflits d’intérêts potentiels susceptibles d’être générés dans le cadre de la détermination de la politique monétaire et de la mise en oeuvre du contrôle prudentiel ont souvent été mis en exergue par les détracteurs du modèle de régulation intégré aux institutions d’émission. Cependant, les influences réciproques ainsi que la complémentarité tenant à l’exercice des missions de stabilité monétaire et de stabilité financière par le banquier central pourraient tendre à justifier l’adoption de telles mesures. La concentration des pouvoirs monétaires et prudentiels dans le giron des banques centrales impliquerait néanmoins pour ces dernières de répondre au principe de la légitimité démocratique, cela tout en conservant un certain degré d’indépendance à l’endroit du pouvoir politique. La conciliation de ces deux exigences semblerait nécessaire dans l’hypothèse où les banques centrales se verraient amenées à exercer un rôle croissant au sein de la sphère financière. Plus largement, c’est peut-être dans la recherche de cet équilibre que réside le secret de la conception d’un cadre institutionnel optimal dans le domaine de la régulation monétaire et financière. Les insuffisances dénoncées des modèles de supervision pourraient-elles ainsi se voir pallier par l’institution d’un Système mondial de banques centrales en charge du contrôle prudentiel ? / With the announcement of the creation of an European banking union, the evolution of institutionnal framework of prudential supervision is currently at the center of political debates. The draft reform provides for the devolution of a significant part of prudential supervision of financial enterprises to the European central bank. The potential conflicts of interest which might be generated in the framework of the determination of monetary policy and the implementation of prudential supervision have often been underlined by critics of the integrated regulatory model within issuing institutions. However, both reciprocal influences and complementarity in the exercice of the missions of monetary stability and financial stability by the central banker might tend to justify the adoption of such measures. The concentration of monetary and prudential powers within central banks would imply, though, for those latter to satisfy the principle of democratic legitimacy, this while keeping some degree of independence from the political power. The conciliation between these two requirements would seem necessary assuming that central banks would be set to exercise an increasingly important role within the financial sphere. More extensively, perhaps the secret of the design of an optimal institutionnal framework in the area of financial and monetary supervision lies in the search for this balance. Might insufficiencies highlighted in supervisory models be overcome by setting up a world system of central banks in charge of prudential supervision?

La spécificité de la tradition monétaire de Henry Thornton, Ralph George Hawtrey, John Maynard Keynes et John Richard Hicks, est de considérer le taux d'intérêt comme une variable influencée par la banque centrale. Ces auteurs peuvent être rattachés à une même tradition monétaire, différente de celle de Knut Wicksell, où le taux d'intérêt est déterminé par une variable réelle: le taux de profit. Dans la tradition de Thornton, le prêt et l'emprunt renvoient une vente et un achat de titres de dette. Ces derniers prennent une forme différente selon la période étudiée. Au dix-neuvième siècle, Thornton proposait que la Banque d'Angleterre contrôle, par des variations de son taux d'escompte, le prix de la liquidité de court-terme, étant la substituabilité des traites commerciales en monnaie. Un siècle plus tard, cette influence était effective. Cependant, au XXe siècle, avec le développement des marchés financiers, d'autre canaux de transmissions de la politique monétaire sont apparus. Bien que négligée par 1 littérature, une des controverses les plus représentatives de cette époque est celle d'Hawtre Keynes et Hicks. Ils conviennent que le taux court est un phénomène monétaire. En revanche, ils ne s'accordent pas sur la nature du taux long. Les débats portent sur la théorie pionnière d Keynes de la structure par terme des taux d'intérêt, les effets d'annonces, ainsi que les limite de l'arbitrage. / The specificity of the monetary tradition of Henry Thornton, Ralph George Hawtrey, John Maynard Keynes and John Richard Hicks is to consider the interest rate as mainly determined by the monetary policy. Those authors are part of the same monetary tradition, different that Knut Wicksell for whom the interest rate is a real variable: the rate of profit. The process of borrowing and lending, in the monetary tradition analyzed in my PhD thesis, corresponds to a sale and a purchase of debts. Debts take a different form according to the period studied. ln the nineteenth century, Thornton wrote that the Bank of England should be able to manage, by varying its discount rate, the price of short-term liquidity, which is the substitution of bills againt money. ln the twentieth century, other transmission channels of monetary policy appeared wit the evolution of financial markets. Although neglected by the literature, one of the most representative controversy at that time was between Hawtrey, Keynes and Hicks. All made a theory in which the short-term rate is a monetary phenomenon. They however disagreed on the nature of the long-term rate. The debate is on Keynes's pioneering theory of the term structur of interest rates, the announcement effects, and the limits to arbitrage.

La présente thèse porte sur « Les Perspectives de Ciblage de l'Inflation dans les Pays de l'UEMOA » dontl'opportunité pourrait être bien saisie à la suite de la nouvelle réforme institutionnelle de l'UMOA et de laBCEAO. Cette réforme doit s'accompagner d'une stratégie opérationnelle explicite dans la mesure où sesinnovations majeures sont très proches d'une politique de ciblage de l'inflation. Pour cela, nous évaluons lapolitique monétaire de la BCEAO axée en partie sur un régime de change fixe depuis les indépendances.Ainsi, après avoir montré la nécessité pour les Banque Centrale d’ancrer les anticipations inflationnistesdans les pays de l'UEMOA et l'apport potentiel de l'annonce d'un objectif d'inflation dans la maîtrise du tauxd'inflation (Chapitre 1), nous montrons que la politique de change fixe n'a pas été à l'origine des tauxd'inflation relativement contenus dans la l'Union, mais pire, elle procure de mauvaises résultats en termesd'une croissance économique élevée et soutenue (Chapitre 2). En cela, nous recommandons pour l’Unionun cadre de type d’une combinaison d’un régime de change intermédiaire et d’une stratégie de ciblage del’inflation. C’est ainsi qu’une cible d’inflation a été déterminée et, elle apparaît différente aussi bien d’un paysà l’autre que de l’objectif de 2% annoncé par le Comité de Politique Monétaire de la BCEAO (Chapitre 3).Nous terminons en déterminant la règle de ciblage d'inflation, et montrons que la meilleure règle optimaleque les autorités monétaires devraient adopter dans un cadre de ciblage de l'inflation concilie l’ancragenominal et la régulation conjoncturelle (Chapitre 4). / This thesis focuses on evaluating the "Prospects of Inflation Targeting in the WAEMU countries" in the wakeof the new institutional reform followed by the WAMU and the BCEAO. This reform must be accompanied byan explicit operational strategy insofar as its major innovations are very close to a policy of inflation targeting.Accordingly, we assess the impact of monetary policy of the BCEAO that focused on fixed exchange ratesince independence. In this respect, we manifest the inability of the fixed exchange rate policy to anchorinflation expectations in the WAEMU countries and the potential contribution regarding the announcement oftarget in controlling inflation (Chapter 1). In addition, we demonstrate, on the one hand, that the fixedexchange rate policy was not the cause of inflation contained in the WAEMU, and on the other, it providespoor results in terms of high and sustained economic growth (Chapter 2). Consequently, we recommend aframework of combination of an intermediate exchange rate regime and an inflation targeting strategy forWAEMU countries. Hence, an inflation target has been determined and it appears to be different from onecountry to another, against the 2% target announced by the Monetary Policy Committee of the BCEAO(Chapter 3). Finally, we define the inflation targeting rule, and show that the best optimal rule that monetaryauthorities adopt in an inflation targeting framework should ideally, reconciles nominal anchor and economicregulation (Chapter 4).

Cette thèse construit un modèle théorique qui renouvelle l’approche traditionnelle de l’équilibre du marché. En introduisant dans le paradigme néo-classique le principe de préférence pour la quantité, il génère de façon optimale des stocks dans un marché concurrentiel. Les résultats sont très importants, car ils expliquent à la fois l’émergence des invendus et l’existence de cycles économiques. En outre, il étudie le comportement optimal du monopole dont la puissance de marché dépend non seulement de la quantité de biens étalés, mais aussi de celle de biens achetés. Contrairement à l’hypothèse traditionnelle selon laquelle le monopoleur choisit le prix ou la quantité qui maximise son profit, il attire, via un indice de Lerner généralisé la demande à la fois par le prix et la quantité de biens exposés. Quelle que soit la structure du marché, le phénomène d’accumulation des stocks de biens apparaît dans l’économie. De plus, il a l’avantage d’expliquer explicitement les achats impulsifs non encore traités par la théorie économique. Pour vérifier la robustesse des résultats du modèle théorique, ils sont testés sur des données américaines. En raison de leur non-linéarité, la méthode de Gauss-Newton est appropriée pour analyser l’impact de la préférence pour la quantité sur la production et l’accumulation de biens, et par conséquent sur les prévisions de PIB. Enfin, cette thèse construit un modèle à générations imbriquées à deux pays qui étend l’équilibre dynamique à un gamma-équilibre dynamique sans friction. Sur la base de la contrainte de détention préalable d’encaisse, il ressort les conditions de sur-accumulation du capital et les conséquences de la mobilité du capital sur le bien-être dans un contexte d’accumulation du stock d’invendus / This thesis constructs a theoretical model that renews the traditional approach of the market equilibrium. By introducing into the neoclassical paradigm the principle of preference for quantity, it optimally generates inventories within a competitive market. The results are very important since they explain both the emergence of unsold goods and the existence of economic cycles. In addition, it studies the optimal behavior of a monopolist whose the market power depends not only on the quantity of displayed goods but also that of goods that the main consumer is willing to buy. Contrary to the traditional assumption that the monopolist chooses price or quantity that maximizes its profit, through a generalized Lerner index (GLI) it attracts customers’ demand by both the price and the quantity of displayed goods. Whatever the market structure, the phenomenon of inventory accumulation appears in the economy. Furthermore, it has the advantage of explicitly explaining impulse purchases untreated by economics. To check the robustness of the results,the theoretical model is fitted to U.S. data. Due to its nonlinearity, the Gauss-Newtonmethod is appropriate to highlight the impact of consumers’ preference for quantity on production and accumulation of goods and consequently GDP forecast. Finally, this thesis builds a two-country overlapping generations (OLG) model which extends the dynamic OLG equilibrium to a frictionless dynamic OLG gamma-equilibrium. Based on the cash-inadvance constraint, it highlights the conditions of over-accumulation of capital and welfare implications of capital mobility in a context of accumulation of stock of unsold goods.

Il y a quatre chapitres dans cette thèse.Dans le premier chapitre, nous analysons les intéractions entre le marché interbancaire et le risque de défaut souverain dans un modèle d’équilibre général à deux pays, en focalisant sur la transmission de la crise financière récente et la politique monétaire non conventionnelle.Dans le deuxième chapitre, les effets de la dévaluation fiscale sur les indicateurs macroéconomiques et le bien être sont analysés en utilisant un modèle à deux pays en union monétaire o`u les variétés de biens et le commerce sont endogènes.Dans le troisième chapitre, l’impact du facteur démographique sur la croissance du secteur des services à long terme est mis en exergue.Dans le quatrième chapitre, on étudie les effets de la mobilité des travailleurs et de la mobilité du capital dans une union monétaire. / This thesis studies challenges for modern developped economies, including the structural change toward services, population ageing, weak labor mobility in the EMU and unconventional monetary policies after the 2008 financial crisis. The manuscript is divided into four chapters.In the first chapter, we analyze the interaction between interbank markets and default risk using a two-country dynamic general equilibrium model, with a focus on the transmission of the recent financial crisis and unconventional monetary policies.In the second chapter, we investigate the effects of fiscal devaluations on key macroeconomic aggregates and welfare using a two-country monetary-union model with endogenous varieties and endogenous tradability.In the third chapter, we study the impact of demographic factor and the growth of service sector by using a multi-sectoral OLG model, and effectuate counterfactual experiments in which the annual growth rate of young generation is ±1pp than the actual growth rate.In the fourth chapter, we study the potential interactions between financial integration and labor mobility in a currency union facing asymmetric shocks, and simulate the impacts of 2008 financial crisis under different mobility costs.

The active use of macroeconomic policies to smooth economic fluctuations and, as a<p>consequence, the stance that policymakers should adopt over the business cycle, remain<p>controversial issues in the economic literature.<p>In the light of the dramatic experience of the early 1930s’ Great Depression, Keynes (1936)<p>argued that the market mechanism could not be relied upon to spontaneously recover from<p>a slump, and advocated counter-cyclical public spending and monetary policy to stimulate<p>demand. Albeit the Keynesian doctrine had largely influenced policymaking during<p>the two decades following World War II, it began to be seriously challenged in several<p>directions since the start of the 1970s. The introduction of rational expectations within<p>macroeconomic models implied that aggregate demand management could not stabilize<p>the economy’s responses to shocks (see in particular Sargent and Wallace (1975)). According<p>to this view, in fact, rational agents foresee the effects of the implemented policies, and<p>wage and price expectations are revised upwards accordingly. Therefore, real wages and<p>money balances remain constant and so does output. Within such a conceptual framework,<p>only unexpected policy interventions would have some short-run effects upon the economy.<p>The "real business cycle (RBC) theory", pioneered by Kydland and Prescott (1982), offered<p>an alternative explanation on the nature of fluctuations in economic activity, viewed<p>as reflecting the efficient responses of optimizing agents to exogenous sources of fluctuations, outside the direct control of policymakers. The normative implication was that<p>there should be no role for economic policy activism: fiscal and monetary policy should be<p>acyclical. The latest generation of New Keynesian dynamic stochastic general equilibrium<p>(DSGE) models builds on rigorous foundations in intertemporal optimizing behavior by<p>consumers and firms inherited from the RBC literature, but incorporates some frictions<p>in the adjustment of nominal and real quantities in response to macroeconomic shocks<p>(see Woodford (2003)). In such a framework, not only policy "surprises" may have an<p>impact on the economic activity, but also the way policymakers "systematically" respond<p>to exogenous sources of fluctuation plays a fundamental role in affecting the economic<p>activity, thereby rekindling interest in the use of counter-cyclical stabilization policies to<p>fine tune the business cycle.<p>Yet, despite impressive advances in the economic theory and econometric techniques, there are no definitive answers on the systematic stance policymakers should follow, and on the<p>effects of macroeconomic policies upon the economy. Against this background, the present thesis attempts to inspect the interrelations between macroeconomic policies and the economic activity from novel angles. Three contributions<p>are proposed. <p><p>In the first Chapter, I show that relying on the information actually available to policymakers when budgetary decisions are taken is of fundamental importance for the assessment of the cyclical stance of governments. In the second, I explore whether the effectiveness of fiscal shocks in spurring the economic activity has declined since the beginning of the 1970s. In the third, the impact of systematic monetary policies over U.S. industrial sectors is investigated. In the existing literature, empirical assessments of the historical stance of policymakers over the economic cycle have been mainly drawn from the estimation of "reduced-form" policy reaction functions (see in particular Taylor (1993) and Galì and Perotti (2003)). Such rules typically relate a policy instrument (a reference short-term interest rate or an indicator of discretionary fiscal policy) to a set of explanatory variables (notably inflation, the output gap and the debt-GDP ratio, as long as fiscal policy is concerned). Although these policy rules can be seen as simple approximations of what derived from an explicit optimization problem solved by social planners (see Kollmann (2007)), they received considerable attention since they proved to track the behavior of central banks and fiscal<p>policymakers relatively well. Typically, revised data, i.e. observations available to the<p>econometrician when the study is carried out, are used in the estimation of such policy<p>reaction functions. However, data available in "real-time" to policymakers may end up<p>to be remarkably different from what it is observed ex-post. Orphanides (2001), in an<p>innovative and thought-provoking paper on the U.S. monetary policy, challenged the way<p>policy evaluation was conducted that far by showing that unrealistic assumptions about<p>the timeliness of data availability may yield misleading descriptions of historical policy.<p>In the spirit of Orphanides (2001), in the first Chapter of this thesis I reconsider how<p>the intentional cyclical stance of fiscal authorities should be assessed. Importantly, in<p>the framework of fiscal policy rules, not only variables such as potential output and the<p>output gap are subject to measurement errors, but also the main discretionary "operating<p>instrument" in the hands of governments: the structural budget balance, i.e. the headline<p>government balance net of the effects due to automatic stabilizers. In fact, the actual<p>realization of planned fiscal measures may depend on several factors (such as the growth<p>rate of GDP, the implementation lags that often follow the adoption of many policy<p>measures, and others more) outside the direct and full control of fiscal authorities. Hence,<p>there might be sizeable differences between discretionary fiscal measures as planned in the<p>past and what it is observed ex-post. To be noted, this does not apply to monetary policy<p>since central bankers can control their operating interest rates with great accuracy.<p>When the historical behavior of fiscal authorities is analyzed from a real-time perspective, it emerges that the intentional stance has been counter-cyclical, especially during expansions, in the main OECD countries throughout the last thirteen years. This is at<p>odds with findings based on revised data, generally pointing to pro-cyclicality (see for example Gavin and Perotti (1997)). It is shown that empirical correlations among revision<p>errors and other second-order moments allow to predict the size and the sign of the bias<p>incurred in estimating the intentional stance of the policy when revised data are (mistakenly)<p>used. It addition, formal tests, based on a refinement of Hansen (1999), do not reject<p>the hypothesis that the intentional reaction of fiscal policy to the cycle is characterized by<p>two regimes: one counter-cyclical, when output is above its potential level, and the other<p>acyclical, in the opposite case. On the contrary, the use of revised data does not allow to identify any threshold effect.<p><p>The second and third Chapters of this thesis are devoted to the exploration of the impact<p>of fiscal and monetary policies upon the economy.<p>Over the last years, two approaches have been mainly followed by practitioners for the<p>estimation of the effects of macroeconomic policies on the real activity. On the one hand,<p>calibrated and estimated DSGE models allow to trace out the economy’s responses to<p>policy disturbances within an analytical framework derived from solid microeconomic<p>foundations. On the other, vector autoregressive (VAR) models continue to be largely<p>used since they have proved to fit macro data particularly well, albeit they cannot fully<p>serve to inspect structural interrelations among economic variables.<p>Yet, the typical DSGE and VAR models are designed to handle a limited number of variables<p>and are not suitable to address economic questions potentially involving a large<p>amount of information. In a DSGE framework, in fact, identifying aggregate shocks and<p>their propagation mechanism under a plausible set of theoretical restrictions becomes a<p>thorny issue when many variables are considered. As for VARs, estimation problems may<p>arise when models are specified in a large number of indicators (although latest contributions suggest that large-scale Bayesian VARs perform surprisingly well in forecasting.<p>See in particular Banbura, Giannone and Reichlin (2007)). As a consequence, the growing<p>popularity of factor models as effective econometric tools allowing to summarize in<p>a parsimonious and flexible manner large amounts of information may be explained not<p>only by their usefulness in deriving business cycle indicators and forecasting (see for example<p>Reichlin (2002) and D’Agostino and Giannone (2006)), but also, due to recent<p>developments, by their ability in evaluating the response of economic systems to identified<p>structural shocks (see Giannone, Reichlin and Sala (2002) and Forni, Giannone, Lippi<p>and Reichlin (2007)). Parallelly, some attempts have been made to combine the rigor of<p>DSGE models and the tractability of VAR ones, with the advantages of factor analysis<p>(see Boivin and Giannoni (2006) and Bernanke, Boivin and Eliasz (2005)).<p><p>The second Chapter of this thesis, based on a joint work with Agnès Bénassy-Quéré, presents an original study combining factor and VAR analysis in an encompassing framework,<p>to investigate how "unexpected" and "unsystematic" variations in taxes and government<p>spending feed through the economy in the home country and abroad. The domestic<p>impact of fiscal shocks in Germany, the U.K. and the U.S. and cross-border fiscal spillovers<p>from Germany to seven European economies is analyzed. In addition, the time evolution of domestic and cross-border tax and spending multipliers is explored. In fact, the way fiscal policy impacts on domestic and foreign economies<p>depends on several factors, possibly changing over time. In particular, the presence of excess<p>capacity, accommodating monetary policy, distortionary taxation and liquidity constrained<p>consumers, plays a prominent role in affecting how fiscal policies stimulate the<p>economic activity in the home country. The impact on foreign output crucially depends<p>on the importance of trade links, on real exchange rates and, in a monetary union, on<p>the sensitiveness of foreign economies to the common interest rate. It is well documented<p>that the last thirty years have witnessed frequent changes in the economic environment.<p>For instance, in most OECD countries, the monetary policy stance became less accommodating<p>in the 1980s compared to the 1970s, and more accommodating again in the<p>late 1990s and early 2000s. Moreover, financial markets have been heavily deregulated.<p>Hence, fiscal policy might have lost (or gained) power as a stimulating tool in the hands<p>of policymakers. Importantly, the issue of cross-border transmission of fiscal policy decisions is of the utmost relevance in the framework of the European Monetary Union and this explains why the debate on fiscal policy coordination has received so much attention since the adoption<p>of the single currency (see Ahearne, Sapir and Véron (2006) and European Commission<p>(2006)). It is found that over the period 1971 to 2004 tax shocks have generally been more effective in spurring domestic output than government spending shocks. Interestingly, the inclusion of common factors representing global economic phenomena yields to smaller multipliers<p>reconciling, at least for the U.K. the evidence from large-scale macroeconomic models,<p>generally finding feeble multipliers (see e.g. European Commission’s QUEST model), with<p>the one from a prototypical structural VAR pointing to stronger effects of fiscal policy.<p>When the estimation is performed recursively over samples of seventeen years of data, it<p>emerges that GDP multipliers have dropped drastically from early 1990s on, especially<p>in Germany (tax shocks) and in the U.S. (both tax and government spending shocks).<p>Moreover, the conduct of fiscal policy seems to have become less erratic, as documented<p>by a lower variance of fiscal shocks over time, and this might contribute to explain why<p>business cycles have shown less volatility in the countries under examination.<p>Expansionary fiscal policies in Germany do not generally have beggar-thy-neighbor effects<p>on other European countries. In particular, our results suggest that tax multipliers have<p>been positive but vanishing for neighboring countries (France, Italy, the Netherlands, Belgium and Austria), weak and mostly not significant for more remote ones (the U.K.<p>and Spain). Cross-border government spending multipliers are found to be monotonically<p>weak for all the subsamples considered.<p>Overall these findings suggest that fiscal "surprises", in the form of unexpected reductions in taxation and expansions in government consumption and investment, have become progressively less successful in stimulating the economic activity at the domestic level, indicating that, in the framework of the European Monetary Union, policymakers can only marginally rely on this discretionary instrument as a substitute for national monetary policies. <p><p>The objective of the third chapter is to inspect the role of monetary policy in the U.S. business cycle. In particular, the effects of "systematic" monetary policies upon several industrial sectors is investigated. The focus is on the systematic, or endogenous, component of monetary policy (i.e. the one which is related to the economic activity in a stable and predictable way), for three main reasons. First, endogenous monetary policies are likely to have sizeable real effects, if agents’ expectations are not perfectly rational and if there are some nominal and real frictions in a market. Second, as widely documented, the variability of the monetary instrument and of the main macro variables is only marginally explained by monetary "shocks", defined as unexpected and exogenous variations in monetary conditions. Third, monetary shocks can be simply interpreted as measurement errors (see Christiano, Eichenbaum<p>and Evans (1998)). Hence, the systematic component of monetary policy is likely to have played a fundamental role in affecting business cycle fluctuations. The strategy to isolate the impact of systematic policies relies on a counterfactual experiment, within a (calibrated or estimated) macroeconomic model. As a first step, a macroeconomic shock to which monetary policy is likely to respond should be selected,<p>and its effects upon the economy simulated. Then, the impact of such shock should be<p>evaluated under a “policy-inactive” scenario, assuming that the central bank does not respond<p>to it. Finally, by comparing the responses of the variables of interest under these<p>two scenarios, some evidence on the sensitivity of the economic system to the endogenous<p>component of the policy can be drawn (see Bernanke, Gertler and Watson (1997)).<p>Such kind of exercise is first proposed within a stylized DSGE model, where the analytical<p>solution of the model can be derived. However, as argued, large-scale multi-sector DSGE<p>models can be solved only numerically, thus implying that the proposed experiment cannot<p>be carried out. Moreover, the estimation of DSGE models becomes a thorny issue when many variables are incorporated (see Canova and Sala (2007)). For these arguments, a less “structural”, but more tractable, approach is followed, where a minimal amount of<p>identifying restrictions is imposed. In particular, a factor model econometric approach<p>is adopted (see in particular Giannone, Reichlin and Sala (2002) and Forni, Giannone,<p>Lippi and Reichlin (2007)). In this framework, I develop a technique to perform the counterfactual experiment needed to assess the impact of systematic monetary policies.<p>It is found that 2 and 3-digit SIC U.S. industries are characterized by very heterogeneous degrees of sensitivity to the endogenous component of the policy. Notably, the industries showing the strongest sensitivities are the ones producing durable goods and metallic<p>materials. Non-durable good producers, food, textile and lumber producing industries are<p>the least affected. In addition, it is highlighted that industrial sectors adjusting prices relatively infrequently are the most "vulnerable" ones. In fact, firms in this group are likely to increase quantities, rather than prices, following a shock positively hitting the economy. Finally, it emerges that sectors characterized by a higher recourse to external sources to finance investments, and sectors investing relatively more in new plants and machineries, are the most affected by endogenous monetary actions. / Doctorat en sciences économiques, Orientation économie / info:eu-repo/semantics/nonPublished