Les réserves de change ont connu des évolutions importantes au cours des deux dernières décennies et ont atteint des niveaux record, en particulier dans les économies émergentes. Ces évolutions ont remis en question les cadres traditionnels d'analyse des motifs de détention des réserves alors que les deux principaux motifs dans la littérature (de précaution et mercantiliste) font face à un certain nombre de limites pour rendre compte de la forte hausse des réserves des émergents dans la période récente. A travers trois études originales dont une analyse détaillée des politiques menées par cinq économies latino-américaines, cette thèse lie l'accumulation récente de réserves à l'accroissement de la liquidité globale et aux contraintes en termes de politiques macroéconomiques auxquelles font face les pays émergents. Elle montre que les réserves de change accumulées ne dépendent pas seulement de facteurs endogènes comme le niveau des fondamentaux (accumulation au titre du motif de précaution) ou le niveau du taux de change (accumulation au titre du motif mercantiliste) mais également de facteurs exogènes, en particulier de la liquidité mondiale. L'accumulation de réserves apparait comme un instrument de politique économique utilisée par les pays émergents afin d'atténuer les contraintes associées au triangle des incompatibilitées. Cette thèse montre que les réserves peuvent être efficaces pour atténuer des contraintes transitoires mais suggère qu'elles ne peuvent empêcher des évolutions structurelles. Dans ce contexte, les choix en termes de policy mix semblent essentiels pour la gestion du trilemme. / Foreign exchange reserves have witnessed important evolutions during the last two decades. They reached all time highs, mostly on account of the acceleration of reserve accumulation in emerging economies. These evolutions have challenged traditional frameworks explaining reserve accumulation' determinants. The two main frameworks (precautionary and mercantilist motivations) face a number of limitations to explain the sharp increase in emerging economies' reserves in the recent period. This dissertation presents three original studies including a detailed analysisof macroeconomic policies conducted by five Latin American economies. It links the accumulation of reserves in the recent period to the increase of global liquidity and to the macroeconomic policy constraints emerging economies face. It shows that reserves do not depend only on pull factors such as the level of fundamentals (accumulation for precautionary purposes) or the level of the exchange-rate (accumulation for mercantilist purposes) but also on push factors, in particular the level of global liquidity. The accumulation of reserves appears as a policy instrumentused by emerging economies to mitigate the constraints associated with the impossible trinity. This dissertation shows that reserves can be efficient in mitigating transitory constraints but suggests that they cannot alter structural evolutions. In this context, the choices in terms of the policy mix appear key to deal with the trilemma.

Depuis l’article séminal de Baks et Kramer (1999), le concept de la liquidité globale est souvent revenu au cœur de l’actualité, car les facteurs de son développement ont été considérés comme ayant indirectement participé aux développements des déséquilibres précédents la crise financière de 2008. Face à ces enjeux, la littérature s’est largement concentrée sur l’approche de la stabilité financière dans les pays émetteurs. Contrairement à cette approche, les recherches développées dans cette thèse se concentrent la perspective des pays destinataires de la liquidité globale, en particulier les pays émergents. Ainsi pour répondre à la problématique principale de l’identification des effets de reports de la liquidité globale, cette thèse propose une analyse en trois chapitres du phénomène. Premièrement, à travers une généralisation de l’analyse de la problématique de la stabilité financière dans les pays émergents. Deuxièmement, en analysant comment le comportement d’accumulation des pays destinataires affecte les conditions de la liquidité globale dans les pays émetteurs. Troisièmement, en analysant au niveau national le comportement des autorités monétaires pour prémunir leurs économies des effets de l’expansion de la liquidité globale. / Since the seminal paper by Baks and Kramer (1999), the concept of global liquidity catch once again the attention because the factors of its expansion are considered in the literature as having contributed to the development of vulnerabilities prior to the global financial crisis. Given the importance of global liquidity issues, the literature has largely focused on the financial stability approach in the issuing countries. Contrary to this approach, the research developed in this Ph.D. thesis relies principally on the receiving countries perspective, particularly the emerging countries. Accordingly, in order to answer our main problematic regarding the identification of global liquidity spillovers into the receiving countries, this thesis proposes a three chapters analysis of the phenomenon. First, we focus on a generalization of the financial stability concerns into the emerging countries. Second, we analyze how the reserve accumulation behavior in the receiving countries affects the global liquidity conditions in the main issuing country. Third, we center on the monetary authorities behavior in order to isolate their economies from the effects of the global liquidity expansion.

This thesis presents three essays on the main determinants and regulations of international capital flows. The essays contribute to an ongoing significant debate among scholars and practitioners on what determines international capital flows by examining the following issues: Global liquidity, market sentiment and financial stability indices; Global liquidity and capital flow regulations; and Global governance and gross capital flows dynamics. In the first essay, we explore the main determinants of global liquidity, measured using cross-border claims of banks, and establish the link between a variety of financial stability indices and global liquidity. For a sample of 149 countries between 2000 and 2016, we find that Bloomberg Financial Stability Indices are more powerful in explaining global liquidity than FRED Financial Stress Indices and the Euro Area Systemic Stress Composite Indicator (CISS). Moreover, both market sentiment indices, namely the US Conference Board Leading Economic Index (LEI) and the US IBD/TIPP Economic Optimism Index are economically and statistically significant on cross-border bank flows. The research provides useful insights on what market sentiment and financial stability indices are better to employ for financial markets surveillance and as such practice of investment management. We argue that anyone interested in using financial stability indices as indicators of financial conditions and the level of financial stress would benefit from tracking several indices and not just one. The second essay examines the effectiveness of capital controls and macroprudential policies as ways to manage the volume of international capital flows, controlling for other determinants. The findings show that capital controls imposed on inflows generally prevail over controls imposed on outflows in reducing the magnitude of capital flows. The results are consistent with the pecking order theory on capital flows and are connected with the riskiness of different asset classes. For a sample of 112 countries over 2000 and 2016, we find that FX and/or countercyclical reserve (RR_REV) and general countercyclical capital buffer requirements (CTC), reserve requirement ratios (RR) and concentration limits (CONC) are the most effective macroprudential policies for managing countries' exposures to global liquidity fluctuations. Moreover, progress is being made to reduce the systemic risks created by systemically important financial institutions (SIFIs) using macroprudential policies. The results reflect recent developments in Basel III regulations and shed light on the effective calibration of capital flow regulations to country-specific circumstances. The final essay examines the link between global governance indicators and patterns of gross capital flows, controlling for other determinants. For a sample of 67 countries between 2000 and 2016, we contribute to explain the existence of the Lucas paradox (1990) on "why doesn't capital flow from rich to poor countries" and the Feldstein-Horioka puzzle (1980). The findings show that institutional quality rather than the effect of diminishing returns of capital is a key explanation for the Lucas paradox. Finally, we provide new evidence on the relationship between the multidimensional nature of financial development and gross capital flows. The findings show the importance and predominance of financial institutions versus financial markets in the dissemination of international capital flows across counties.

L’int´erˆet pour la liquidit´e mondiale s’est accru ces derni`eres ann´ees, motiv´e essentiellement parla complexit´e de ce concept et ces effets encore peu connus sur l’´economie, les march´es financierset les ´economies ´emergentes. Les travaux de cette th`ese visent `a contribuer `a cette litt´eratureen ´etudiant, dans un premier temps, les facteurs macro´economiques et financiers `a l’origine dela dynamique de la liquidit´e mondiale et de son allocation sur les diff´erents march´es du globe.Dans un second temps, quelques effets de l’´evolution de la liquidit´e mondiale sont analys´esen se focalisant sur les ´economies ´emergentes et les d´es´equilibres globaux. Nous montronstout d’abord que l’´etat de l’´economie r´eelle ainsi que celui des march´es financiers d´eterminentconsid´erablement l’´evolution de la liquidit´e mondiale avec des nuances selon qu’il s’agit d’unep´eriode de crise ou d’une p´eriode de croissance. Les autorit´es mon´etaires, et dans une grandemesure la R´eserve F´ed´erale am´ericaine, ont un rˆole tr`es important dans cette dynamique globaleet sa r´epartition dans le monde. Les pays ´emergents, receveurs de capitaux, sont impact´es parces flux qui affectent consid´erablement leur ´economie r´eelle. Toutefois, l’effet sur les march´esfinanciers dans ces pays reste limit´e, contrebalanc´e par les acquisitions d’actifs libell´es en devises´etrang`eres d´etenus par les investisseurs locaux. Quant aux d´es´equilibres globaux, la liquidit´emondiale pourrait ˆetre int´egr´ee aux indicateurs avanc´es permettant d’expliquer l’´evolution deces d´es´equilibres. L’int´erˆet pour la liquidit´e mondiale et son suivi sont donc tout `a fait justifi´es. / The interest in Global Liquidity has increased in recent years due essentially to the complexityof the concept and its less known effects on the real economy, the financial markets, and theemerging economies. This dissertation contributes to the Global Liquidity literature by studying,firstly, the macroeconomic and financial determinants, which drive global liquidity dynamicsand its allocation on different markets of the world. Secondly, some of global liquidity effects,focusing on emerging economies and global imbalances are analysed. The results of these worksprove that the state of real economy as well as those of financial markets impact dramaticallythe global liquidity dynamics depending on boom and bust periods. The monetary authorities,and to a greater extent the U.S. Federal Reserve, have a significant role in this global dynamicsand its global allocation. The real activity in emerging economies is significantly impacted bycapital inflows. However, the effects on financial markets are dampened by the offsetting effectsof assets purchased in foreign currencies from local investors. In regard to global imbalancesissues, global liquidity can be added to leading indicators, which help explaining the dynamicsof these imbalances. It is therefore, useful to track the dynamics of global liquidity.

[pt] Quais devem ser a características da política monetária ótima sob comprometimento em uma situação de armadilha da liquidez global quando os Bancos Centrais não coordenam suas ações? Fazendo o uso de um modelo de economia aberta com dois países, fizemos um exercício numérico para endereçar essa questão e estudar as diferenças entre este caso e uma situação cooperativa, na qual as autoridades monetárias não estão somente preocupadas com a utilidade da população nacional, mas em vez disso maximizam uma medida de bem-estar global. Nossas descobertas apontam para diferenças nas características de dependência histórica e internacional da prescrição monetária em cada um dos casos observados. Também é feita uma análise de bem-estar do nosso experimento que sugere que um Banco Central local prefere, não só permanecer restrito pelo limite inferior zero da taxa de juros nominal por um período maior, mas também que o país estrangeiro saia dessa situação o quanto antes. Por fim, fazemos uma análise de robustez dos nossos resultados variando o tamanho de cada nação e o grau de substituição dos produtos produzidos em cada localidade. / [en] What should be the characteristics of the optimal monetary policy under commitment in the situation of a global liquidity trap when Central Banks do not coordinate their actions? Using a two-country open economy model, we perform a numerical exercise in order to address this question and study the differences between this setting and a cooperative situation, when monetary authorities are not only worried with the national household utility, but instead maximize a measure of world welfare. Our findings points towards differences of history and international dependence features of optimal monetary prescriptions in each of the observed cases. We also execute a welfare analysis of our experiment that suggests that a local Central Bank prefers, not only to stay restrained by zero lower bound (ZLB) on nominal interest rates for a longer period, but also that the foreign country exists this situation as early as possible. Lastly, we make a robustness analysis of our results varying the size of each nation and the degree of substitution of the composite goods produced in each locality.

[pt] Tarifas comerciais podem ser usadas para auxiliar o Banco Central na estabilização da economia? Para responder essa pergunta construímos um modelo Novo Keynesiano de economia aberta com dois países onde as firmas têm poder de mercado suficientemente alto para definir preços diferentes para o mercado local e estrangeiro e obtemos a política monetária e tarifária ótima sob a existência de um limite inferior para a taxa nominal de juros. Fazendo um exercício numérico, analisamos duas situações: quando apenas um país se encontra em uma armadilha de liquidez e quando ambos os países se encontram presos em uma armadilha de liquidez global. Nossos resultados sugerem, que mesmo quando os dois países estão cooperando, a existência do limite inferior da taxa de juros nominal gera uma situação onde o uso ativo de tarifas comerciais pode aumentar o bem-estar da economia. / [en] Can trade tariffs be used to help the Central Bank stabilize the economic cycle? To answer that question we build a New Keynesian Open Economy model with two different countries and where firms have enough market power to set prices in both Home and Foreign markets and calculate the optimal monetary and tariff policy under the existence of a Zero Lower Bound on the nominal interest rate. We perform a numerical exercise to analyse two distinct situations: when only one country is restricted by the Zero Lower Bound and when both countries face this constraint. Our results suggest that the Zero Lower Bound creates a situation in which active use of trade tariffs can be optimal, even if countries are cooperating.