Ce travail étudie les couts et bénéfices liés à l'accroissement de la transparence dans les politiques d'interventions des banques centrales sur le marché des changes. Il s'articule autour de quatre articles de recherche. Chaque article repose sur des méthodes économétriques récentes et une base de données originale (politique de la banque centrale japonaise de 1991 à 2004).

The subject of this study is to examine the determinants of the real exchange rate in Taiwan. The sample period is from the first quarter of 1982 to the second quarter of 2011, and the variables include the real exchange rate, terms of trade, productivity differential, the real oil price, reserve differential, real interest rate differential, and the net foreign assets of Taiwan and America. The empirical results show that there is no cointegration between the real exchange rate and independent variables. Using a VAR model, this study finds that although the central bank of Taiwan would intervenes the real exchange rate, the variable related to the economic growth is still significant. At 5% significance level, an increase in the productivity differential leads the real exchange rate to depreciate. In addition, from the result of the granger causality test, this study finds that there exists unidirectional causality from the productivity differential and central bank intervention respectively to the real exchange rate. The effect of central bank intervention on the real exchange rate only persists one period, and the effect of the productivity differential persists two more periods. Therefore, it can be concluded that when estimating the future real exchange rate, it may be useful to take the productivity differential into account.

The diploma thesis is focused on the origin and development of the world financial crisis started in 2007 and its analysis. The steps taken by the European Central Bank and the Czech National Bank to respond to this crisis are then analyzed. Furthermore, the work shows the impact of the crisis and central bank measures on two selected domestic banks. At the end of the thesis are made suggestions and recommendations.

在這篇文章裡我們採用了White所提出的真實檢驗法(Reality Check)來解決探勘資料偏誤(Data-snooping bias)的問題，結果顯示從1980年到2008年間，技術分析法則的確可以幫助投資人在日圓兌美元及英鎊兌美元這兩個外匯市場獲利；我們也發現在外匯市場最普遍的技術分析方式─移動平均法(moving average)表現不如其他的技術分析法則，而通道突破法(channel break-out)的表現則明顯優於其他技術分析法則。 除了檢驗技術分析方法的獲利性之外，我們也嘗試著探討技術分析方法的獲利性與央行干預之間的關係，追隨Szacmary與Mathur在1997年所發表的論文，我們把技術分析法則擴充為在真實檢驗法中所使用到的所有法則，並且盡可能加長分析的期間。結果顯示技術分析法則的獲利與央行干預並不存在任何特定的關係。 / In this paper we construct a huge universe of simple trading rules and apply White’s Reality Check to mitigate data-snooping bias then detect the profitability of technical trading rules. We find that technical analysis is useful no matter in the full sample time or each subsample period. The channel break-out method outperforms the other methods in our finding while the profitability of the most commonly used moving average method is worse than the others. Furthermore, we inspect the relationships between the returns of technical trading rules and central bank intervention. The results suggest that there’s no evident relationship between the return series of trading rules and central bank intervention and are not consistent with the view of our following previous study.

Submitted by Alysson Oliveira Lima (alyssonlima@hotmail.com) on 2014-02-20T12:28:37Z No. of bitstreams: 1 DISSERTACAO FINAL - Alysson Oliveira Lima.pdf: 1422126 bytes, checksum: ea07829e7f2fef5ba62cea63d58dab7a (MD5) / Approved for entry into archive by Suzinei Teles Garcia Garcia (suzinei.garcia@fgv.br) on 2014-02-20T12:59:52Z (GMT) No. of bitstreams: 1 DISSERTACAO FINAL - Alysson Oliveira Lima.pdf: 1422126 bytes, checksum: ea07829e7f2fef5ba62cea63d58dab7a (MD5) / Made available in DSpace on 2014-02-20T13:03:40Z (GMT). No. of bitstreams: 1 DISSERTACAO FINAL - Alysson Oliveira Lima.pdf: 1422126 bytes, checksum: ea07829e7f2fef5ba62cea63d58dab7a (MD5) Previous issue date: 2014-01-28 / Desde a adoção do sistema de câmbio flutuante pelo Banco Central do Brasil, tanto a autoridade monetária quanto o governo brasileiro têm instituído medidas convencionais e não convencionais de intervenção no mercado de câmbio. Dentre essas medidas, salientam-se as compras e vendas de dólares no mercado de spot e derivativos, cujas finalidades precípuas seriam a tentativa de estabilizar os mercados em situação de 'stress' e suavizar uma determinada tendência de valorização ou desvalorização da moeda brasileira. O presente trabalho analisa os efeitos de referidas intervenções sobre a volatilidade na moeda brasileira. Utilizamos modelos econométricos da família ARCH (Autoregressive Conditional Heteroskedasticity) com o intuito de se averiguar o efeito sobre a volatilidade de curto e longo prazo, inclusive com metodologias semelhantes às empregadas em trabalhos direcionados a outras economias emergentes. Com o propósito de se estudar o efeito sinalizador das intervenções, foram utilizadas regressões simples com dados de volatilidade implícita e risk reversal do mercado de opções do dólar/real. Concluiu-se pela não relevância dos efeitos das intervenções sobre o nível da taxa de câmbio. No que concerne às volatilidades de curto e longo prazo, verificou-se que as vendas de dólares aumentam ambas as volatilidades, porém, quanto às compras, estas não apresentaram significância. No que se refere aos efeitos sinalizadores, via volatilidade implícita e risk reversal, estes também não expuseram relevância. Enfim, o que talvez possa consistir em fundamento para a não relevância dessas intervenções é o fato de o Brasil se consubstanciar em uma economia emergente e com menor credibilidade na condução de suas políticas monetárias. / Since Brazilian Central Bank adopted the floating exchange rate system, both the monetary authority and the Brazilian government have established conventional and unconventional measures to intervene in the foreign exchange market. Among these measures, it is important to emphasize the buying and selling dollars event in the spot and derivatives market, whose main purposes are to stabilize markets in distressful situations and to soften a particular trend of brazilian currency’s appreciation or depreciation. This paper exactly analyzes the effects of such interventions on the Brazilian currency volatility. We investigated the effect on the volatility of short and long terms, by means of ARCH (Autoregressive Conditional Heteroskedasticity) type models. To study the interventions signaling effect, we employed simple regressions with implied volatility and risk reversal of options market dollar/real. We are eligible that the effects of these interventions on the level of the exchange rate. Regarding the volatility of short and long term, selling dollars increases both volatilities, however, for the purchases, these did not show significant change. As for signaling effects, through implied volatility and risk reversal, effects are not relevant. We conjecture that the irrelevance of this interventions is due to the lack of credibility of the brazilian monetary policy

Submitted by LEANDRO NOGUEIRA (leandrorn@gmail.com) on 2014-08-28T22:16:08Z No. of bitstreams: 1 Dissertacao - Leandro Nogueira - Final v4 revisada.pdf: 519776 bytes, checksum: 82bc4931efb8bca136b105499bc136b4 (MD5) / Approved for entry into archive by Gisele Gammaro (gisele.gammaro@fgv.br) on 2014-08-29T17:23:52Z (GMT) No. of bitstreams: 1 Dissertacao - Leandro Nogueira - Final v4 revisada.pdf: 519776 bytes, checksum: 82bc4931efb8bca136b105499bc136b4 (MD5) / Approved for entry into archive by Gisele Gammaro (gisele.gammaro@fgv.br) on 2014-08-29T17:40:54Z (GMT) No. of bitstreams: 1 Dissertacao - Leandro Nogueira - Final v4 revisada.pdf: 519776 bytes, checksum: 82bc4931efb8bca136b105499bc136b4 (MD5) / Made available in DSpace on 2014-09-24T12:49:38Z (GMT). No. of bitstreams: 1 Dissertacao - Leandro Nogueira - Final v4 revisada.pdf: 519776 bytes, checksum: 82bc4931efb8bca136b105499bc136b4 (MD5) Previous issue date: 2014-05-28 / This work aims to investigate the effect of foreign exchange interventions by the Central Bank of Brazil on the intraday level of the exchange rate in Brazil. An event study approach is applied, correlating the tick-by-tick quotations of traded dollar future contracts at BM&FBOVESPA with the moment the interventions occurred, from October 2011 to March 2014. The analysis considered not only the moment of the intervention but also the moment of the announcement. Results indicated that the market reacts differently to each type of intervention, and reactions are sharper when interventions are not previously announced to the market. Interventions via currency swap or dollar spot generated significant and relevant effects on the level of the exchange rate. On the other hand, interventions that had sale/purchase auction with repurchase/resale commitment did not affect significantly the exchange rate. / Este trabalho tem como objetivo investigar o efeito das intervenções cambiais realizadas pelo Banco Central do Brasil sobre o nível intradiário da taxa de câmbio no Brasil. Para isso é utilizada uma abordagem de estudo de eventos, cruzando as cotações tick-by-tick dos contratos de dólar futuro negociados na BM&FBOVESPA com o instante em que ocorreram as intervenções, no período de outubro de 2011 a março de 2014. Foram considerados nas análises não apenas o momento da intervenção como também o momento do anúncio. Os resultados indicaram que o mercado reage de forma distinta a cada tipo de intervenção, sendo a reação acentuada quando a intervenção não é anunciada previamente ao mercado. As intervenções via swap cambial ou dólar pronto geraram efeitos significativos e relevantes no nível da taxa de câmbio. Por outro lado, as intervenções através de leilão de linha não afetaram significativamente a taxa de câmbio.