主权债务风险跨国溢出研究——来自频域的新证据

本文从国家间主权债务风险溢出的持续期角度出发,采用基于广义方差分解谱表示的BK溢出指数方法,首次从频域视角对短期和长期下的主权债务风险跨国溢出效应进行研究。研究发现:第一,短期和长期下的主权债务风险跨国溢出效应均较为显著,并且时域下的总溢出主要由短期的风险溢出主导。第二,14个国家的短期和长期风险输出水平呈线性关系,但对于风险输入,不同类型国家出现分化并形成两个聚类,新兴市场国家的短期风险输入水平远高于长期,其具有较强的"短期脆弱性"。第三,风险输出国的自身风险越大,对他国的长期溢出水平越高,风险输入国的自身风险越大,接收他国的短期溢出水平越高,并且两两国家间的进出口规模、金融市场一体化水平和经济周期协同性与其长期风险溢出水平呈正相关关系,而与其短期风险溢出水平的关系并不显著。第四,短期和长期的主权债务风险溢出网络都呈现明显的区域聚集特征,并且各国在短期溢出网络中主要与同区域以及经济金融环境相似的国家连接,在长期溢出网络中则通过经贸关系将连接范围扩大至不同区域甚至经济金融环境差异较大的国家。     

主权债务风险跨国溢出研究——来自频域的新证据

本文从国家间主权债务风险溢出的持续期角度出发,采用基于广义方差分解谱表示的BK溢出指数方法,首次从频域视角对短期和长期下的主权债务风险跨国溢出效应进行研究。研究发现:第一,短期和长期下的主权债务风险跨国溢出效应均较为显著,并且时域下的总溢出主要由短期的风险溢出主导。第二,14个国家的短期和长期风险输出水平呈线性关系,但对于风险输入,不同类型国家出现分化并形成两个聚类,新兴市场国家的短期风险输入水平远高于长期,其具有较强的“短期脆弱性”。第三,风险输出国的自身风险越大,对他国的长期溢出水平越高,风险输入国的自身风险越大,接收他国的短期溢出水平越高,并且两两国家间的进出口规模、金融市场一体化水平和经济周期协同性与其长期风险溢出水平呈正相关关系,而与其短期风险溢出水平的关系并不显著。第四,短期和长期的主权债务风险溢出网络都呈现明显的区域聚集特征,并且各国在短期溢出网络中主要与同区域以及经济金融环境相似的国家连接,在长期溢出网络中则通过经贸关系将连接范围扩大至不同区域甚至经济金融环境差异较大的国家。     

Private information in currency markets

Using daily abnormal currency returns for the universe of countries with flexible exchange rates, we show local currency depreciations ahead of unscheduled, public sovereign debt downgrade announcements. Consistent with the private information hypothesis, the effect is stronger in lower institutional quality countries and holds after we control for concurrent public information and for publicly available rumors about the forthcoming downgrades. Our results persist when abnormal currency returns are adjusted for global carry and dollar risk factors, world equity and bond returns, as well as local stock market returns. Finally, the currency depreciations are permanent, providing evidence for a link between fundamentals and currency markets.     

A sovereign risk index for the Eurozone based on stochastic dominance

We propose a new method to assess sovereign risk in Eurozone countries using an approach that relies on consistent tests for stochastic dominance efficiency. The test statistics and the estimators are computed using mixed integer programming methods. Our analysis is based on macroeconomic fundamentals and their importance in accounting for sovereign risk. The results suggest that net international investment position/GDP and public debt/GDP are the main contributors to country risk in the Eurozone. We also conduct ranking analysis of countries for fiscal and external trade risk. We find a positive correlation between our rankings of the most vulnerable countries and the S&P’s ratings, whereas the correlation for other countries is weaker.     

Sovereign asset values and implications for the credit market

Using the contingent claim approach and market data on sovereign credit default swaps we assess the drivers of a country's risk perception. Deriving market-based asset values for a set of advanced economies we gain insights into the capital markets' perspectives on sovereign creditworthiness. We find the market-based asset values to be positively influenced by debt and to be an early risk indicator for economic developments. In a cross-section analysis we identify drivers of the economic risk of countries. Clustering the countries according to their debt to asset value ratios provides further insights into the market perceptions of sovereign credit risk. For example we find that the asset values of countries with higher ratios react to changes in the global equity market. Countries with a lower ratio react more to the political stability within the country.     

The anatomy of sovereign risk contagion

The channels for the cross-border propagation of sovereign risk in the international sovereign debt market are analysed. Identifying sovereign credit events as extraordinary jumps in CDS spreads, we distinguish between the immediate effects of such events and their longer term spillover effects. To analyse “fast and furious” contagion, we use daily CDS data to conduct event studies around a total of 89 identified credit events in a global country sample. To analyse “slow-burn” spillover effects, we apply a multifactor risk model, distinguishing between global and regional risk factors. We find that “fast and furious” contagion has been primarily a regional phenomenon, whilst “slow-burn” spillover effects can often be global in scope, especially those of the recent European debt crisis. The global risk factors are found to be driven by investor risk appetites and debt levels, whilst the regional factors depend on economic fundamentals of countries within a region.     

Is small beautiful? The resilience of small banks during the European debt crisis

We examine the lending behaviour of small and large banks in the Eurozone during the sovereign debt crisis. Relative to large banks, small banks are less pro-cyclical in that they exhibit more stable lending growth across credit expansion and contraction periods. In peripheral countries, the portfolio rebalancing of small banks towards higher public debt (substitution effect) does not appear to cause a reduction of their lending to the private sector. Instead, the level of public debt seems to provide a liquidity buffer that influences bank-specific loan growth positively (complementarity effect), particularly during market-wide lending contractions. Our findings show that for small peripheral banks the substitution effect found in the literature can coexist with a complementarity effect when public debt grows faster than private loans. Our analysis contributes to the ongoing debate on the regulatory treatment of public debt in banks and supports incentives embedded in new banking regulation that penalise bank size.     

What is the risk of European sovereign debt defaults? Fiscal space,CDS spreads and market pricing of risk

We estimate the pricing of sovereign risk for fifty countries based on fiscal space (debt/tax; deficits/tax) and other economic fundamentals over 2005–10. We focus in particular on five countries in the South-West Eurozone Periphery, Greece, Ireland, Italy, Portugal and Spain. Dynamic panel estimates show that fiscal space and other macroeconomic factors are statistically and economically important determinants of sovereign risk. However, risk-pricing of the Eurozone Periphery countries is not predicted accurately either in-sample or out-of-sample: unpredicted high spreads are evident during global crisis period, especially in 2010 when the sovereign debt crisis swept over the periphery area. We match the periphery group with five middle income countries outside Europe that were closest in terms of fiscal space during the European fiscal crisis. Eurozone Periphery default risk is priced much higher than the matched countries in 2010, even allowing for differences in fundamentals. One interpretation is that these economies switched to a “pessimistic” self-fulfilling expectational equilibrium. An alternative interpretation is that the market prices not on current but future fundamentals, expecting adjustment challenges in the Eurozone periphery to be more difficult for than the matched group of middle-income countries because of exchange rate and monetary constraints.     

Sovereign risk,public debt,dollarization, and the output effects of fiscal austerity

The goal of this paper is to investigate effects of fiscal policy on output as a response to an external shock at different levels and currency compositions of public debt. Central to our analysis is the mutual relationship between sovereign risk and public debt on the one hand, and the linkage between sovereign risk and private credit spreads on the other. We show that fiscal austerity is conducive to real economic activity when initial government debt is high, its foreign currency share is important, and the link between sovereign and corporate spreads is strong.     

Public debt,sovereign default risk and shadow economy

This paper analyzes the interactions between government's indebtedness, sovereign default risk and the size of the informal sector. We test an underlying theory that suggests that in societies with limited tax enforcement, the presence of informality constrains the set of pledgeable fiscal policy alternatives, increases public debt and the implied probability of sovereign debt restructuring. The hypotheses that we test in our empirical analysis are: a larger size of the informal sector is associated with (1) higher public indebtedness, (2) higher interest rates paid on sovereign debt, (3) a higher level of financial instability and (4) a higher probability of sovereign default. The empirical results from cross-country panel regressions show that after controlling for previously highlighted variables in the literature that could explain the variation in financial instability, sovereign default risk and public indebtedness, the size of informality remains as a significant determinant of these variables.     

A comprehensive approach to measuring the relation between systemic risk exposure and sovereign debt

Using an integrated model to control for simultaneity, as well as new risk measurement techniques such as Adapted Exposure CoVaR and Marginal Expected Shortfall (MES), we show that the aggregate systemic risk exposure of financial institutions is positively related to sovereign debt yields in European countries in an episodic manner, varying positively with the intensity of the financial crisis facing a particular nation. We find evidence of a simultaneous relation between systemic risk exposure and sovereign debt yields. This suggests that models of sovereign debt yields should also include the systemic risk of a country's financial system in order to avoid potentially important mis-specification errors. We find evidence that systemic risk of a country's financial institutions and the risk of sovereign governments are inter-related and shocks to these domestic linkages are stronger and longer lasting than international risk spillovers. Thus, the channel in which domestic sovereign debt yields can be affected by another nation's sovereign debt is mostly an indirect one in that shocks to a foreign country's government finances are transmitted to that country's financial system which, in turn, can spill over to the domestic financial system and, ultimately, have a destabilizing effect on the domestic sovereign debt market.     

Sovereign credit spreads

The paper develops a structural credit risk model to study sovereign credit risk and the dynamics of sovereign credit spreads. The model features endogenous default and recovery rates that both depend on the interaction between domestic output fluctuations and global macroeconomic conditions. We show that sovereigns choose to default at higher levels of economic output once global macroeconomic conditions are bad. This yields to default rates and credit spreads that are substantially higher compared to normal times. We derive closed-form expressions for sovereign debt values and default times and focus on the dynamics of sovereign credit spreads. As opposed to standard theories of sovereign debt, this paper’s structural model generates much richer default patterns and non-linearities through regime-shifts in the global macroeconomic environment. Moreover, changes in the global environment reveal the interconnectedness of the financial system.     

Governance and bank characteristics in the credit and sovereign debt crises – the impact of CEO power

The global financial sector recently suffered from two interrelated crises: the credit crisis and the sovereign debt crisis. A common question is whether the recent experience with the credit crisis has helped in dealing with the sovereign debt crisis. We study more specifically whether banks with powerful CEOs perform better or worse than other banks, and if there is any difference in this relationship between the two crises. Using unique hand-collected data for 378 large global banks, we find that CEO power has a significant positive relation to bank profitability and asset quality, but also to insolvency risk, during the sovereign debt crisis. Thus, strong CEOs do not appear to be detrimental to bank performance. Our results also support the idea that deposit insurance may have contributed to the credit crisis.     

Towards an early warning system for sovereign defaults leveraging on machine learning methodologies

In this study, we address the topic of credit risk stemming from central governments from a technical point of view. First, we explore various econometric and machine learning techniques to build an enhanced sovereign rating system that effectively differentiates the risk of default among countries. Our empirical results indicate that the machine learning method of XGBOOST has a superior out-of-sample and out-of-time predictive performance. Then, we use the models developed to calibrate a sovereign rating system and provide useful insights into the set-up of a parsimonious early warning system. Our results provide a more concise view of the most robust method for classifying countries’ default risk with significant regulatory implications, given that the efficient assessment of sovereign debt is crucial for effective proactive risk measurement.     

Sovereign risk spillovers: A network approach

Understanding the global financial network for sovereign debt, particularly with a focus on interaction and spillover effects of sovereign risk, has become important for policy makers as they look to protect the stability of their economies. Using high dimensional Vector Autoregression techniques and network simulation on Sovereign Credit Default Swaps (CDS)’ data of 57 countries, we identify that the global sovereign CDS network is fully integrated as there is virtually no country without any connection to at least one specific node in the system. However, each country has a unique attribute in the network, as a risk exporter or importer and/or risk transmitter. Among developed countries, the US (unsurprisingly) holds the dominant position as a risk exporter while Germany is identified as a connecting country that transmits shocks. The most connected countries in the sovereign CDS network belong to the new European Union members. We examine possible drivers of the network relationships observed, in order to better understand the risk transmission process, and find that connections in the sovereign risk network are stronger within regional groups and countries with the same level of economic development. Central and Eastern Europe and Middle East and Africa have more interactive networks than Northern Western Europe, Asia Pacific and Latin America. We also identify that financial volatility and economic policy uncertainty increase the interactions in market-based default risk assessment.     

What determines the share of non-resident public debt ownership? Evidence from Euro Area countries

This paper provides, for the first time, a detailed picture of the composition of public debt by type of holder (foreign vs. domestic) and type of holding institution for a set of 7 Euro Area countries between 1991Q1 and 2015Q4. In addition, it empirically inspects the determinants of nonresident public debt ownership, accounting for both domestic and external factors and paying special attention to the global financial crisis period. Using a previously unexplored dataset and by means of panel and country-specific time series regressions, we find that improved fiscal positions, systemic stress and financial volatility, a strong business cycle position, all increase share of public debt held by non-residents. Also, a higher share of monetary and financial institutions cross-border holdings of sovereign debt issued by the other Euro Area countries was correlated with higher share of public debt held by non-residents. Finally, results are robust to outliers inspection and other sensitivity checks.     

Factor decomposition of the Eurozone sovereign CDS spreads

In the present study, we examine the factors driving Eurozone sovereign credit default swap (CDS) spreads during the Eurozone sovereign debt crisis. For identifying factors we utilize independent component analysis (ICA), a technique similar to principal component analysis (PCA). We identify three factors that impact spreads and capture the features specific to the crisis such as the breakup risk of the Eurozone: peripheral factor, global factor, and Eurozone common factor. In contrast, when PCA is applied, only a single factor is identified. Moreover, using ICA with a GARCH model, we show that the source of volatility for CDS spreads shifted from the global factor in 2009 and the peripheral factor in 2010 to the Eurozone common factor in 2012, and that the dynamic correlation reflects the decoupling between low credit risk countries such as Germany and high credit risk countries such as Greece. We also show that the goodness-of-fit of the ICA-based model is better than other models used such as the Student's t copula model.     

Modelling correlation dynamics of EMU sovereign debt markets during the recent turmoil

The purpose of the present study is to explicitly model the correlation dynamics of Eurozone sovereign debt markets. Our analysis runs from 2000 through 2014. Time varying correlations are derived from a dynamic conditional correlation GARCH model (t-cDCC model). We document substantial variability in correlations that is time and region-dependent. Evidence suggests that the Lehman collapse coupled with the German banks’ bailout programme and the events that followed have undermined sovereign debt integration. Moreover, sensitivity analysis provides useful insights that global and regional risk factors play pivotal role in explaining correlation structure both before and after the onset of the Eurozone sovereign debt crisis. We believe that our results entail important implications for market authorities, international fixed income portfolio diversification and asset allocation.     

关于欧洲主权债务问题与欧元区域制度改革的思考

近来,希腊、葡萄牙、西班牙和爱尔兰等多个欧元区国家均面临主权债务违约风险。这一问题的发生,既有希腊等国自身财政管理的原因,也反映出欧元区体制中存在的一系列长期性、结构性和制度性问题。如果不能妥善解决欧元区国家的主权债务问题,不仅将拖累欧元区经济发展,也会对世界经济金融复苏造成冲击。欧洲主权债务问题的出现,对我国财政预算管理也有一定警示作用。