The structure and resilience of financial market networks

Financial markets can be viewed as a highly complex evolving system that is very sensitive to economic instabilities. The complex organization of the market can be represented in a suitable fashion in terms of complex networks, which can be constructed from stock prices such that each pair of stocks is connected by a weighted edge that encodes the distance between them. In this work, we propose an approach to analyze the topological and dynamic evolution of financial networks based on the stock correlation matrices. An entropy-related measurement is adopted to quantify the robustness of the evolving financial market organization. It is verified that the network topological organization suffers strong variation during financial instabilities and the networks in such periods become less robust. A statistical robust regression model is proposed to quantity the relationship between the network structure and resilience. The obtained coefficients of such model indicate that the average shortest path length is the measurement most related to network resilience coefficient. This result indicates that a collective behavior is observed between stocks during financial crisis. More specifically, stocks tend to synchronize their price evolution, leading to a high correlation between pair of stock prices, which contributes to the increase in distance between them and, consequently, decrease the network resilience. (C) 2012 American Institute of Physics. [doi:10.1063/1.3683467]

Econometric models of financial risks

The goal of this dissertation is to use statistical tools to analyze specific financial risks that have played dominant roles in the US financial crisis of 2008-2009. The first risk relates to the level of aggregate stress in the financial markets. I estimate the impact of financial stress on economic activity and monetary policy using structural VAR analysis. The second set of risks concerns the US housing market. There are in fact two prominent risks associated with a US mortgage, as borrowers can both prepay or default on a mortgage. I test the existence of unobservable heterogeneity in the borrower's decision to default or prepay on his mortgage by estimating a multinomial logit model with borrower-specific random coefficients.

Quantifying and modeling financial market fluctuations

Die Entstehung eines Marktpreises für einen Vermögenswert kann als Superposition der einzelnen Aktionen der Marktteilnehmer aufgefasst werden, die damit kumulativ Angebot und Nachfrage erzeugen. Dies ist in der statistischen Physik mit der Entstehung makroskopischer Eigenschaften vergleichbar, die von mikroskopischen Wechselwirkungen zwischen den beteiligten Systemkomponenten hervorgerufen werden. Die Verteilung der Preisänderungen an Finanzmärkten unterscheidet sich deutlich von einer Gaußverteilung. Dies führt zu empirischen Besonderheiten des Preisprozesses, zu denen neben dem Skalierungsverhalten nicht-triviale Korrelationsfunktionen und zeitlich gehäufte Volatilität zählen. In der vorliegenden Arbeit liegt der Fokus auf der Analyse von Finanzmarktzeitreihen und den darin enthaltenen Korrelationen. Es wird ein neues Verfahren zur Quantifizierung von Muster-basierten komplexen Korrelationen einer Zeitreihe entwickelt. Mit dieser Methodik werden signifikante Anzeichen dafür gefunden, dass sich typische Verhaltensmuster von Finanzmarktteilnehmern auf kurzen Zeitskalen manifestieren, dass also die Reaktion auf einen gegebenen Preisverlauf nicht rein zufällig ist, sondern vielmehr ähnliche Preisverläufe auch ähnliche Reaktionen hervorrufen. Ausgehend von der Untersuchung der komplexen Korrelationen in Finanzmarktzeitreihen wird die Frage behandelt, welche Eigenschaften sich beim Wechsel von einem positiven Trend zu einem negativen Trend verändern. Eine empirische Quantifizierung mittels Reskalierung liefert das Resultat, dass unabhängig von der betrachteten Zeitskala neue Preisextrema mit einem Anstieg des Transaktionsvolumens und einer Reduktion der Zeitintervalle zwischen Transaktionen einhergehen. Diese Abhängigkeiten weisen Charakteristika auf, die man auch in anderen komplexen Systemen in der Natur und speziell in physikalischen Systemen vorfindet. Über 9 Größenordnungen in der Zeit sind diese Eigenschaften auch unabhängig vom analysierten Markt - Trends, die nur für Sekunden bestehen, zeigen die gleiche Charakteristik wie Trends auf Zeitskalen von Monaten. Dies eröffnet die Möglichkeit, mehr über Finanzmarktblasen und deren Zusammenbrüche zu lernen, da Trends auf kleinen Zeitskalen viel häufiger auftreten. Zusätzlich wird eine Monte Carlo-basierte Simulation des Finanzmarktes analysiert und erweitert, um die empirischen Eigenschaften zu reproduzieren und Einblicke in deren Ursachen zu erhalten, die zum einen in der Finanzmarktmikrostruktur und andererseits in der Risikoaversion der Handelsteilnehmer zu suchen sind. Für die rechenzeitintensiven Verfahren kann mittels Parallelisierung auf einer Graphikkartenarchitektur eine deutliche Rechenzeitreduktion erreicht werden. Um das weite Spektrum an Einsatzbereichen von Graphikkarten zu aufzuzeigen, wird auch ein Standardmodell der statistischen Physik - das Ising-Modell - auf die Graphikkarte mit signifikanten Laufzeitvorteilen portiert. Teilresultate der Arbeit sind publiziert in [PGPS07, PPS08, Pre11, PVPS09b, PVPS09a, PS09, PS10a, SBF+10, BVP10, Pre10, PS10b, PSS10, SBF+11, PB10].

The Law and Economics of Hedge Fund Regulation: A Comparison between the U.S. and the EU

This doctoral dissertation seeks to assess and address the potential contribution of the hedge fund industry to financial instability. In so doing, the dissertation investigates three main questions. What are the contributions of hedge funds to financial instability? What is the optimal regulatory strategy to address the potential contribution of hedge funds to financial instability? And do new regulations in the U.S. and the EU address the contribution of hedge funds to financial instability? With respect to financial stability concerns, it is argued that despite their benefits, hedge funds can contribute to financial instability. Hedge funds’ size and leverage, their interconnectedness with Large Complex Financial Institutions (LCFIs), and the likelihood of herding behavior in the industry can potentially undermine financial stability. Nonetheless, the data on hedge funds’ size and leverage suggest that these features are far from being systemically important. In contrast, the empirical evidence on the interconnectedness of hedge funds with LCFIs and their herding behavior is mixed. Based on these findings, the thesis focuses on one particular aspect of hedge fund regulation: direct vs. indirect regulation. In this respect, a major contribution of the thesis to the literature consists in the explicit discussion of the relationships between hedge funds and other market participants. Specifically, the thesis locates the domain of the indirect regulation in the inter-linkages between hedge funds and prime brokers. Accordingly, the thesis argues that the indirect regulation is likely to address the contribution of hedge funds to systemic risk without compromising their benefits to financial markets. The thesis further conducts a comparative study of the regulatory responses to the potential contribution of hedge funds to financial instability through studying the EU Directive on Alternative Investment Fund Managers (AIFMD) and the hedge fund-related provisions of the Dodd-Frank Wall Street Reform and Consumer Protection Act of 2010.

UMA ANÁLISE DA RELAÇÃO ENTRE VARIÁVEIS MACROECONÔMICAS E O COMPORTAMENTO DAS AÇÕES DE MAIOR LIQUIDEZ DO ÍNDICE IBOVESPA

As ações de maior liquidez do índice IBOVESPA, refletem o comportamento das ações de um modo geral, bem como a relação das variáveis macroeconômicas em seu comportamento e estão entre as mais negociadas no mercado de capitais brasileiro. Desta forma, pode-se entender que há reflexos de fatores que impactam as empresas de maior liquidez que definem o comportamento das variáveis macroeconômicas e que o inverso também é uma verdade, oscilações nos fatores macroeconômicos também afetam as ações de maior liquidez, como IPCA, PIB, SELIC e Taxa de Câmbio. O estudo propõe uma análise da relação existente entre variáveis macroeconômicas e o comportamento das ações de maior liquidez do índice IBOVESPA, corroborando com estudos que buscam entender a influência de fatores macroeconômicos sobre o preço de ações e contribuindo empiricamente com a formação de portfólios de investimento. O trabalho abrangeu o período de 2008 a 2014. Os resultados concluíram que a formação de carteiras, visando a proteção do capital investido, deve conter ativos com correlação negativa em relação às variáveis estudadas, o que torna possível a composição de uma carteira com risco reduzido.

International financial regulation: A role for the Eurozone? EU Diplomacy Paper 08/2012, October 2012

The deepest financial crisis to strike the global economy since the Great Depression has unceremoniously called into question the very foundations of the Western economic model. The liberalisation of capital flows and the growing internationalisation of financial markets outpaced global regulatory and supervisory efforts. The repercussions of the financial crisis have given new dynamism to the reform of financial regulation both globally and within the European Union (EU). The Eurozone, by way of its own failings, has emerged as a stronger conceptual and legitimate entity since the onset of the crisis, but to what extent does this equate to a greater external role, in particular in the reform of international financial regulation? This paper argues that the Eurozone is currently not in a position to play an important role in the reform of international financial regulation, as it is a weak actor in the context of the EU financial architecture, which is still largely characterised by differing national regimes, a prevailing influence from the UK and fragmented external representation. The key finding from this study is that internal tensions in the EU are at the very heart of the Eurozone’s difficulties in playing a role in the reform of international financial regulation. Surmounting these tensions is a pre-requisite for the Eurozone if it is to overcome its structural weakness in international financial politics. However, the implications of such evolutions to the Eurozone, as an entity, and to European integration are far-reaching.

Financial services and the Transatlantic Trade and Investment Partnership. CEPS Policy Brief No. 302, 20 November 2013

Given the size of the financial markets on both sides of the Atlantic and the symmetry in the follow-up of the G-20 standards, Karel Lannoo argues in this Policy Brief that the Transatlantic Trade and Investment Partnership (TTIP) provides a good opportunity to put in place a more institutionalised framework. He finds that both blocs have reacted in similar ways to the financial crisis in strengthening their regulatory and supervisory frameworks and incorporating the G-20 recommendations into federal law. He also notes that consumer protection has been reinforced, certainly in the US, with the creation of the Consumer Financial Protection Bureau. And on the EU side, the Single Supervisory Mechanism (SSM) will radically change banking supervision. In his view, inclusion of financial services could also be an opportunity to strengthen prudential rules and consumer protection provisions on both sides. Rather than leading to a reduction of consumer protection, as had been feared in the post-crisis environment, it could lead to an examination, exchange and recognition of best practices in regulation and enforcement. Finally, he concludes that inclusion of financial services would make it part of the permanent regulatory dialogue that will be established as a result of a successful TTIP.

Europe between financial repression and regulatory capture. Bruegel Working Paper 2014/08, July 2014

From the Introduction. In the long shadow of the euro-area crisis, the relationship between governments and their banks has been brought to the the centre of the policy debate in Europe by the implementation of regulatory reforms, the risks associated with financial fragmentation, and the fight to sustain the flow of credit to governments and corporates. The attempt to interpret the patterns of pressure and influence running between governments and their financial system has led commentators to rediscover and give new life to concepts originating from academic debates of the 1970s such as “regulatory capture” and “financial repression”. Government agencies have been frequently described as being at the mercy of the financial sector, often allowing financial interests to hijack political, regulatory and supervisory processes in order to favouring their own private interests over the public good1. An opposite view has instead pointed the finger at governments, which have often been portrayed as subverting markets and abusing the financial system to their benefit, either in order to secure better financing conditions to overcome their own financial difficulties, or with the objective of directing credit to certain sectors of the economy, “repressing” the free functioning of financial markets and potentially the private interests of some of its participants2

Financial Transaction Tax (FTT): Why the EU needs the FTT but the FTT does not need the EU. EPC Policy Brief, 17 June 2014

Through an Enhanced Cooperation Procedure (ECP) 11 eurozone countries (ECP-11) – among them the four biggest; Germany, France, Italy and Spain – have aspired to go ahead with the introduction of a Financial Transaction Tax (EU-FTT). Apart from generating substantial revenues for tight fiscal budgets, an EU-FTT could also contribute to the reduction of transactions, which are harmful for the efficient functioning of financial markets and the real economy. However, the willingness to go forward with the finalisation of an ambitious proposal has lost some momentum recently; some of the envisaged compromises may even threaten the viability of the whole project.

Enhancing European Cooperation in Financial Supervision and Crisis Management. ACES Working Papers, August 2009

To overcome the regulatory pitfalls, regulatory capacity and resources in financial markets governance need to be enhanced, not only at national but also at global levels. In order to shed light on policy issues and agendas in international financial policy cooperation, this paper focuses on the case of European financial integration and regulations. The analysis of policy developments at the European level in coordinating differing national interests, supervisory systems, and practices among EU member states highlights fundamental elements of global financial regulatory cooperation.

Achieving European Policy Objectives through Financial Technology. ECRI Commentary No. 17, 16 November 2015

Alistair Milne argues in this ECRI Commentary that ‘FinTech’ (newly emerging Financial Technologies) can play a crucial role in achieving European policy objectives in the area of financial markets. These notably include increasing access by smaller firms to trade credit and other forms of external finance and completing the banking and capital markets unions. He points out, however, that accomplishing these objectives will require a coordinated European policy response, focused especially on promoting common business processes and the adoption of shared technology and data standards.

Squaring the cycle: capital flows, financial cycles, and macro-prudential policy in the euro area. Bruegel Working Paper 2015/14, November 2015

• Before the financial and economic crisis, monetary policy unification and interest rate convergence resulted in the divergence of euroarea countries’ financial cycles. This divergence is deeply rooted in the financial integration spurred by currency union and strongly correlated with intra-euro area capital flows. Macro-prudential policy will need to deal with potentially divergent financial cycles, while catering for potential cross-border spillovers from domestic policies, which domestic authorities have little incentive to internalise. • The current framework is unfit to deal effectively with these challenges. The European Central Bank should be responsible for consistent and coherent application of macro-prudential policy, with appropriate divergences catering for national differences in financial conditions. The close link between domestic financial cycles and intra-euro area capital flows raises the question of whether macro-prudential policy in the euro area can be compatible with free flows of capital. Financial cycle divergence had its counterpart in the build-up of macroeconomic imbalances, so effective implementation of the Macroeconomic Imbalance Procedure would support and strengthen macro-prudential policy.

European Bank Resolution: Making it work! Interim report of the CEPS Task Force on Implementing Financial Sector Resolution. CEPS Task Force Report, January 2016

From the start of 2016, new rules for bank resolution are in place – as spelled out in the Bank Recovery and Resolution Directive (BRRD) – across the EU, and a new authority (the Single Resolution Board, or SRB) is fully operational for resolving all banks in the eurozone. The implementation issues of the new regime are enormous. Banks need to develop recovery plans, and authorities need to create resolution plans as well as set the minimum required amount of own funds and eligible liabilities (MREL) for each bank. But given the diversity in bank structures and instruments at EU and global level, this will be a formidable challenge, above all with respect to internationally active banks. In order to explore ways in which the authorities and banks can meet this challenge, CEPS formed a Task Force composed of senior experts on banking sector reform and chaired by Thomas Huertas, Partner and Chair, EY Global Regulatory Network. This report contains its policy recommendations.

The Challenges of the EU Banking Union - will it succeed in dealing with the next financial crisis? Bruges European Economic Policy Briefings 36/2015

The EU Banking Union combines micro- and macro-prudential regulation. It aims at breaking the “doom loop” between banks and sovereign debt, promoting financial stability and mitigating the next financial shock to the real EU economy, at the lowest possible cost to the financial institutions and to the taxpayers. Success, or failure, is determined by how the banking union copes with the challenges to its two main pillars, the Single Supervisory Mechanism (SSM) and the Single Resolution Mechanism (SRM). Under the SSM, in its new supervisory role, the ECB may be subject to conflicts between the objectives of price and financial stability, and the single-supervisor role may be sub-optimal. Two regulators might have been preferable and more focus on ECB accountability will now be required. The shock-absorbing Single Resolution Fund (SRF), which is part of the SRM, may not have the capacity to deal with a crisis of the size of the one of 2008. Especially as the nature and severity of a future financial crisis cannot be forecasted. The design of the banking union is not the result of theoretical studies, but a political compromise to deal with an acute crisis. The theoretical studies that are included in this paper are not supportive of the banking union in its current form. Nevertheless, there is a good chance that the EU Banking Union may succeed, as ECB supervision of the 123 systemically important banks should contain potential demands on the SRM. In the event of a crisis that is too severe for the banking union to absorb with its current capability, the crucial assumption is that there is political will to rapidly provide new resources. The same applies, if a major financial crisis develops before the banking union is fully operational.

The Challenges of the EU Banking Union - will it succeed in dealing with the next financial crisis? Bruges European Economic Policy (BEEP) Briefings 36/2015

The EU Banking Union combines micro- and macro-prudential regulation. It aims at breaking the “doom loop” between banks and sovereign debt, promoting financial stability and mitigating the next financial shock to the real EU economy, at the lowest possible cost to the financial institutions and to the taxpayers. Success, or failure, is determined by how the banking union copes with the challenges to its two main pillars, the Single Supervisory Mechanism (SSM) and the Single Resolution Mechanism (SRM). Under the SSM, in its new supervisory role, the ECB may be subject to conflicts between the objectives of price and financial stability, and the single-supervisor role may be sub-optimal. Two regulators might have been preferable and more focus on ECB accountability will now be required. The shock-absorbing Single Resolution Fund (SRF), which is part of the SRM, may not have the capacity to deal with a crisis of the size of the one of 2008. Especially as the nature and severity of a future financial crisis cannot be forecasted. The design of the banking union is not the result of theoretical studies, but a political compromise to deal with an acute crisis. The theoretical studies that are included in this paper are not supportive of the banking union in its current form. Nevertheless, there is a good chance that the EU Banking Union may succeed, as ECB supervision of the 123 systemically important banks should contain potential demands on the SRM. In the event of a crisis that is too severe for the banking union to absorb with its current capability, the crucial assumption is that there is political will to rapidly provide new resources. The same applies, if a major financial crisis develops before the banking union is fully operational.