The hedging effect of green bonds on carbon market risk

This paper explores effective hedging instruments for carbon market risk. Examining the relationship between the carbon futures returns and the returns of four major market indices, i.e., the VIX index, the commodity index, the energy index and the green bond index, we find that the connectedness between the carbon futures returns and the green bond index returns is the highest and this connectedness is extremely pronounced during the market's volatile period. Further, we develop and evaluate hedging strategies based on three dynamic hedge ratio models (DCC-APGARCH, DCC-T-GARCH, and DCC-GJR-GARCH models) and the constant hedge ratio model (OLS model). Empirical results show that among the four market indices the green bond index is the best hedge for carbon futures and performs well even in the crisis period. The paper also provides evidence that the dynamic hedge ratio models are superior to the OLS model in the volatile period as more sophisticated models can capture the dynamic correlation and volatility spillover between the carbon futures and market index returns.     

Regime switching correlation hedging

This paper investigates the hedging effectiveness of commodity futures when the correlations of spot and futures returns are subject to multi-state regime shifts. An independent switching dynamic conditional correlation GARCH (IS-DCC) which is free from the problems of path-dependency and recombining is applied to model multi-regime switching correlations. The results of hedging exercises indicate that state-dependent IS-DCC outperforms state-independent DCC GARCH and three-state IS-DCC exhibits superior hedging effectiveness, illustrating importance of modeling higher-state switching correlations for dynamic futures hedging.     

基于沪铜期货的套期保值比率与效率比较的实证分析

本文以沪铜期货的多头套期保值为研究对象,分别利用OLS模型、ECM模型和GARCH模型对一月期铜和三月期铜的套期保值比例及保值效果进行了分析,发现OLS模型对一月期铜的套期保值效果要优于其他模型的保值效果,而ECM模型和GARCH模型在三月期铜的套期保值方面显示的效果更好。这说明在一般情况下,具有动态特征的计量模型适合于较长的期货合约,其套期保值效果更好。     

Size effect,methodological issues and ‘risk-to-default’: evidence from the UK stock market

The hedging effectiveness of dynamic strategies is compared with static (traditional) ones using futures contracts for the five leading currencies. The traditional hedging model assumes time invariance in the joint distribution of spot and futures price changes thus leading to a constant optimal hedge ratio (OHR). However, if this time-invariance assumption is violated, time-varying OHRs are appropriate for hedging purposes. A bivariate GARCH model is employed to estimate the joint distribution of spot and futures currency returns and the sequence of dynamic (time-varying) OHRs is constructed based upon the estimated parameters of the conditional covariance matrix. The empirical evidence strongly supports time-varying OHRs but the dynamic model provides superior out-of-sample hedging performance, compared to the static model, only for the Canadian dollar.     

An asymmetric dynamic conditional correlation analysis of linkages of European financial institutions during the Greek sovereign debt crisis

This article employs the asymmetric dynamic conditional correlation (DCC) model to assess impacts of the recent sovereign debt crisis on the time-varying correlations of five European financial institutions holding large amounts of Greek sovereign bonds (National Bank of Greece, BNP Paribas, Dexia, Generali, and Commerzbank). Contrary to the results of preceding studies, we find significant increases in the correlations between several combinations of the financial institutions’ stock returns after the inception of the sovereign debt crisis, indicating contagion effects. Moreover, our findings show that the parameter of the standardized negative residuals is statistically significant in the case of DCC estimates between two specific institutions. This suggests that the conditional correlation of stock returns between the two institutions is more significantly influenced by negative shocks than by positive innovations to return.     

Hedging with futures: Efficacy of GARCH correlation models to European electricity markets

European electricity markets have been subject to a broad deregulation process in the last few decades. We analyse hedging policies implemented through different hedge ratios estimation. More specifically we compare naïve, ordinary least squares, and GARCH conditional variance and correlations models to test if GARCH models lead to higher variance reduction in a context of high time varying volatility as the case of electricity markets. Our results show that the choice of the hedge ratio estimation model is central on determining the effectiveness of futures hedging to reduce the portfolio volatility.     

A regime-switching real-time copula GARCH model for optimal futures hedging

A regime-switching real-time copula GARCH (RSRTCG) model is suggested for optimal futures hedging. The specification of RSRTCG is to model the margins of asset returns with state-dependent real-time GARCH and the dependence structure of asset returns with regime switching copula functions. RSRTCG is faster in adjusting to the new level of volatility under different market regimes which is a regime-switching multivariate generalization of the state-independent univariate real-time GARCH. RSRTCG is applied to cross hedge the price risk of S&P 500 sector indices with crude oil futures. The empirical results show that RSRTCG possesses superior hedging performance compared to its nested non-real-time or state-independent copula GARCH models based on the criterion of percentage variance reduction, utility gain, model confidence set, model combination strategy, risk-adjusted return and reward-to-semivariance ratio.     

Short-run deviations and time-varying hedge ratios: Evidence from agricultural futures markets

This paper investigates the hedging effectiveness of time-varying hedge ratios in the agricultural commodities futures markets using four different versions of the GARCH models. The GARCH models applied are the standard bivariate GARCH, the bivariate BEKK GARCH, the bivariate GARCH-X and the bivariate BEKK GARCH-X. Futures data for corn, coffee, wheat, sugar, soybeans, live cattle and hogs are applied. Comparison of the hedging effectiveness is done for the within sample period (1980–2004), and two out-of-sample periods (2002–2004 and 2003–2004). Results indicate superior performance of the portfolios based on the GARCH-X model estimated hedge ratio during all periods.     

Banks and sovereign risk: A granular view

We investigate the determinants of sovereign bond holdings of German banks and the implications of such holdings for bank risk. We use granular information on all German banks and all sovereign debt exposures in the years 2005–2013. As regards the determinants of sovereign bond holdings of banks, we find that these are larger for weakly capitalized banks, banks that are active on capital markets, and for large banks. Yet, only around two thirds of all German banks hold sovereign bonds. Macroeconomic fundamentals were significant drivers of sovereign bond holdings only after the collapse of Lehman Brothers. With the outbreak of the sovereign debt crisis, German banks reallocated their portfolios toward sovereigns with lower debt ratios and bonds with lower yields. With regard to the implications for bank risk, we find that low-risk government bonds decreased the risk of German banks, especially for savings and cooperative banks. Holdings of high-risk government bonds, in turn, increased the risk of commercial banks during the sovereign debt crisis.     

Currency futures market in India: an empirical analysis of market efficiency and volatility

As the Indian currency futures market has been in existence for over 7 years, this paper analyses the effectiveness of the 1-month USD/INR currency futures rates in predicting the expected spot rate. The volatility of the USD/INR spot returns was also analysed. Modelling volatility of the USD/INR spot rate using a generalized autoregressive conditional heteroskedasticity (GARCH) and exponential generalized autoregressive conditional heteroskedasticity (EGARCH) model indicated the presence of volatility clustering. Using multivariate GARCH models such as the constant conditional correlation and dynamic conditional correlation, signs of a volatility spillover between the USD/INR spot and currency futures market were also observed.     

An international analysis of REITs and stock portfolio management based on dynamic conditional correlation models

This paper analyzes the volatility spillovers and asymmetry between REITs and stock prices for nine countries (Australia, Belgium, Germany, Italy, Japan, The Netherlands, Singapore, the United Kingdom, and the United States) using eight different multivariate GARCH models. We also analyze the optimal weights, hedging effectiveness, and hedge ratios for REIT-stock portfolio holdings with respect to the results. The empirical results indicate that dynamic conditional correlation (DCC) models provide a better fit than the constant conditional correlation models. The DCC with volatility spillovers and asymmetry (DCC-SA) model provides a better fit than the other multivariate GARCH models. The DCC-SA model also provides the best hedging effectiveness for all pairs of REIT-stock assets. More importantly, this result holds for all cases and for all models that we consider, which means that by taking spillover and asymmetry into consideration, hedging effectiveness can be vastly improved.     

Transmission of the financial and sovereign debt crises to the EMU: Stock prices,CDS spreads and exchange rates

This paper tests for the transmission of the 2007–2010 financial and sovereign debt crises to fifteen EMU countries. We use daily data from 2003 to 2010 on country financial and non-financial stock market indexes to analyze the stock market returns for three country groups within EMU: North, South and Small. The following results hold for both the North and South European countries, while the smallest countries seem to be relatively isolated from international events. First, we find strong evidence of crisis transmission to European non-financials from US non-financials, but not for financials. Second, in order to test how the sovereign debt crisis affects stock market developments we split the crisis in pre- and post-Lehman sub periods. Results show that financials become significantly more dependent on changes in the difference between the Greek and German CDS spreads after Lehman’s collapse, compared to the pre-Lehman sub period. However, this increase is much smaller for non-financials. Third, before the crisis euro appreciations coincide with European stock market decreases, whereas this relationship reverses during the crisis. Finally, this reversal seems to be triggered by Lehman’s collapse.     

Testing for a break in the persistence in yield spreads of EMU government bonds

This study tests for a break in the persistence of EMU government bond yield spreads examining data from France, Italy and Spain and using German interest rates as a kind of benchmark. The results reported here provide evidence for breaks between 2006 and 2008. The persistence of the yield spreads against German government bonds has increased significantly after this period. This could be a sign of higher sovereign credit risk (and possibly even redenomination risk) caused by the debt crisis in the euro area. We find clear indications for non-stationary behavior after the breakpoints and empirical evidence for positive excess kurtosis and GARCH-effects when persistence increases.     

Vine copulas and applications to the European Union sovereign debt analysis

European sovereign debt crisis has become a very popular topic since late 2009. In this paper, sovereign debt crisis is investigated by calculating the probabilities of the potential future crisis of 11 countries in the European Union. We use sovereign spreads of the European countries against Germany as targets and apply the GARCH based vine copula simulation technique. The methodology solves the difficulties of calculating the probabilities of rarely happening events and takes sovereign debt movement dependence, especially tail dependence, into consideration. Results indicate that Italy and Spain are the most likely next victims of the sovereign debt crisis, followed by Ireland, France and Belgium. The UK, Sweden and Denmark, which are outside the euro area, are the most financially stable countries in the sample.     

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.     

Sovereign credit rating determinants: A comparison before and after the European debt crisis

This paper compares the importance of different sovereign credit rating determinants over time, using a sample of 90 countries for the years 2002–2015. Applying the composite marginal likelihood approach, we estimate a multi-year ordered probit model for each of the three major credit rating agencies. After the start of the European debt crisis in 2009, the importance of the financial balance, the economic development and the external debt increased substantially and the effect of eurozone membership switched from positive to negative. In addition, GDP growth gained a lot of importance for highly indebted sovereigns and government debt became much more important for countries with a low GDP growth rate. These findings provide empirical evidence that the credit rating agencies changed their sovereign credit rating assessment after the start of the European debt crisis.     

An economic evaluation of stock–bond return comovements with copula-based GARCH models

Owing to their importance in asset allocation strategies, the comovements between the stock and bond markets have become an increasingly popular issue in financial economics. Moreover, the copula theory can be utilized to construct a flexible joint distribution that allows for skewness in the distribution of asset returns as well as asymmetry in the dependence structure between asset returns. Therefore, this paper proposes three classes of copula-based GARCH models to describe the time-varying dependence structure of stock–bond returns, and then examines the economic value of copula-based GARCH models in the asset allocation strategy. We compare their out-of-sample performance with other models, including the passive, the constant conditional correlation (CCC) GARCH and the dynamic conditional correlation (DCC) GARCH models. From the empirical results, we find that a dynamic strategy based on the GJR-GARCH model with Student-t copula yields larger economic gains than passive and other dynamic strategies. Moreover, a less risk-averse investor will pay higher performance fees to switch from a passive strategy to a dynamic strategy based on copula-based GARCH models.     

Integration of European bond markets

I investigate the time variation in the integration of EU government bond markets. The integration is measured by the explanatory power of European factor portfolios for the individual bond markets for each year. The integration of the government bond markets is stronger for EMU than non-EMU members and stronger for old than new EU members. For EMU countries, the integration is weaker the lower the credit rating is. During the recent crisis periods, the integration is weaker, particularly for EMU countries.     

STOCK INDEX FUTURES HEDGING: HEDGE RATIO ESTIMATION, DURATION EFFECTS, EXPIRATION EFFECTS AND HEDGE RATIO STABILITY

This paper examines hedging effectiveness for the FTSE-100 Stock Index futures contract from 1984 to 1992. It investigates the appropriate econometric technique to use in estimating minimum variance hedge ratios by undertaking estimations using OLS, an ECM and GARCH. Simple OLS outperforms more complex econometric techniques. Additionally, the paper examines the impact ofhedge duration and time to expiration on estimated hedge ratios and hedge ratio stability over time. It is shown that hedge ratios and hedging effectiveness increase with hedge duration, hedge ratios approach unity as expiration approaches and while hedge ratios vary over time they are stationary.     

Can negative interest rates really affect option pricing? Empirical evidence from an explicitly solvable stochastic volatility model

The profound financial crisis generated by the collapse of Lehman Brothers and the European sovereign debt crisis in 2011 have caused negative values of government bond yields both in the USA and in the EURO area. This paper investigates whether the use of models which allow for negative interest rates can improve option pricing and implied volatility forecasting. This is done with special attention to foreign exchange and index options. To this end, we carried out an empirical analysis on the prices of call and put options on the US S&P 500 index and Eurodollar futures using a generalization of the Heston model in the stochastic interest rate framework. Specifically, the dynamics of the option’s underlying asset is described by two factors: a stochastic variance and a stochastic interest rate. The volatility is not allowed to be negative, but the interest rate is. Explicit formulas for the transition probability density function and moments are derived. These formulas are used to estimate the model parameters efficiently. Three empirical analyses are illustrated. The first two show that the use of models which allow for negative interest rates can efficiently reproduce implied volatility and forecast option prices (i.e. S&P index and foreign exchange options). The last studies how the US three-month government bond yield affects the US S&P 500 index.