Tail dependence between gold and sectorial stocks in China: perspectives for portfolio diversification

This article analyzes the relationship between gold quoted on the Shanghai Gold Exchange and Chinese sectorial stocks from 2009 to 2015. Using different copulas, our results show that there is weak but significant tail dependence between gold and Chinese sectorial stock returns. This means that the dependence between extreme movements of the two assets is not pronounced and confirms the role of gold as a safe haven asset. Based on analyzing the efficient frontier, CCC-GARCH optimal weights, hedge ratios and hedging effectiveness, we further show that adding gold into Chinese stock portfolios can help to reduce their risk. Gold appears to be the most efficient diversifier for stocks of the materials sector and the less efficient for the utilities sector. As a robustness check, we also compare gold to oil and indicate that gold is more efficient than oil in the diversification of Chinese stock portfolios.

     

Portfolio Diversification Strategy Via Tail‐Dependence Clustering and ARMA‐GARCH Vine Copula Approach

This study proposes a diversified portfolio construction method based on the tail dependence between the financial assets and adopting both market prior information and the exports’ subject views. In this paper, tail‐dependence clustering was applied to divide candidate assets into different groups according to their tail dependence during the crisis period and the ARMA‐GARCH vine copula‐opinion pooling approach was applied to select the minimum Conditional Value‐at‐Risk portfolio according to the clustering results. The daily closed prices of the components of DAX 20 from 3 January 2006 to 20 December 2014 were studied to illustrate the methodology. The results reveal that more than 90% of 450 possible portfolios are modelled by D‐vine structure and Student's t‐copula dominates almost all the cases for pair copula selection. As Student's t‐copula captures the symmetric tail dependence, the 450 possible portfolios do not show stronger lower tail dependence than upper tail dependence. This study contributes by combining cluster analysis with portfolios selection. It uses vine copula to capture the dependence structure among assets. Finally, it offers a flexible method to describe market and offers a strategy to construct diversified portfolios by adding the investors’ information into portfolio selection procedure at the 1‐day forecast horizon.     

Portfolios in the Ibex 35 before and after the Global Financial Crisis

In this article, we present an analysis of the effectiveness of various portfolio optimization strategies applied to the stocks included in the Spanish Ibex 35 index, for a period of 14 years, from 2001 until 2014. The period under study includes episodes of volatility and instability in financial markets, incorporating the Global Financial Crisis and the European Sovereign Debt Crisis. This implies a challenge in portfolio optimization strategies since the methodologies are restricted to the assignment of positive weights. We have taken for asset allocation the daily returns with an estimation window equal to 1 year and we hold portfolio assets for another year. This article attempts to influence the discussion over whether the naive diversification proves to be an effective strategy as opposed to portfolio optimization models. For that, we evaluate the out-of-sample performance of 15 strategies for asset allocation in the Ibex 35, before and after of the Global Financial Crisis. Our results suggest that a large number of strategies outperform to the 1/N rule and to the Ibex 35 index in terms of return, Sharpe ratio and lower VaR and CVaR. The mean-variance portfolio of Markowitz with short-sale constraints is the only strategy that renders a Sharpe ratio statistically different from Ibex 35 index in the 2001–2007 and 2008–2014 time periods.     

考虑基准资产的动态投资组合选取

职业基金经理的目标经常是希望自己的投资组合以稳定的表现能够超越所某一基准资产或组合。因此本文给出一个考虑基准资产的动态均值——方差投资组合选取模型。假设状态之间的转移遵循马氏过程,给定状态转移矩阵,可以得到对风险资产最优投入的解析表达式。此表达式表明对风险资产的投入由三项构成,前两项是不考虑基准资产时对风险资产的投入,最后一项与基准资产有关;在基准资产上的权重由基准资产收益的大小来决定,与积极投资组合管理者的风险厌恶程度无关;随着风险厌恶程度的增加,管理者会减少在风险资产上的投入。数值分析显示考虑基准资产的投资组合是一个积极的投资组合。     

Tail dependence analysis of stock markets using extreme value theory

Financial risk modelling frequently uses the assumption of a normal distribution when considering the return series which is inefficient if the data is not normally distributed or if it exhibits extreme tails. Estimation of tail dependence between financial assets plays a vital role in various aspects of financial risk modelling including portfolio theory and hedging amongst applications. Extreme Value Theory (EVT) provides well established methods for considering univariate and multivariate tail distributions which are useful for forecasting financial risk or modelling the tail dependence of risky assets. The empirical analysis in this article uses nonparametric measures based on bivariate EVT to investigate asymptotic dependence and estimate the degree of tail dependence of the ASX-All Ordinaries daily returns with four other international markets, viz., the S&P-500, Nikkei-225, DAX-30 and Heng-Seng for both extreme right and left tails of the return distribution. It is investigated whether the asymptotic dependence between these markets is related to the heteroscedasticity present in the logarithmic return series using GARCH filters. The empirical evidence shows that the asymptotic extreme tail dependence between stock markets does not necessarily exist and rather can be associated with the heteroscedasticity present in the financial time series of the various stock markets.     

Analyzing the dependence structure of various sectors in the Brazilian market: A Pair Copula Construction approach

In this paper we estimate the dependence structure between economic sectors in the Brazilian financial market through Pair Copula Construction. We use daily data from indices which represent telecommunications, energy, industrials, consumer, financial, basic materials and real estate sectors in BM&F/Bovespa. Results indicate predominance of student's t copula in structure. BB1, BB7, BB8, Frank and Joe copulas also fit into some relationships. Regarding dependence, tail measures obtain relevant values in most relationships. Lower tail dependence exceeds absolute, measured by Kendall's Tau, and upper tail in many cases, reflecting the asymmetry in some relationships. Further, in order to give robustness to these results, we forecast daily Value at Risk, considering distinct significance levels, of a portfolio composed of studied sectors through the estimated structure. Results allow one to conclude that VaR predictions are correct. These results permit business industry participants to construct portfolios with assets of these sectors under a proper diversification structure. Moreover, from an international point of view, investors who are interested in diversification could perform more sophisticated strategies in this country rather than simply trading the index.     

Risk forecasting models and optimal portfolio selection

This study analyses, from an investor's perspective, the performance of several risk forecasting models in obtaining optimal portfolios. The plausibility of the homoscedastic hypothesis implied in the classical Markowitz model is dicussed and more general models which take into account assymetry and time varying risk are analysed. Specifically, it studies whether ARCH-type based models obtain portfolios whose risk-adjusted returns exceed those of the classical Markowitz model. The same analysis is performed with models based on the Lower Partial Moment (LPM) which take into account the assymetry in the distribution of returns. The results suggest that none of the models achieve a clearly superior average performance. It is also found that models based on semivariance perform as well as those based on the variance, but not better than, even if the evaluation criterion is based on the Reward-to-Semivariance ratio. When attention turns to the analysis of worst case performance, the results are clearly different. Models which employ LPM with a high degree of risk aversion (n>2) as the risk measure are consistently superior to those which employ a symmetric measure, either homoscedastic or heteroscedastic.     

Modelling VaR for foreign-asset portfolios in continuous time

VaR is widely viewed as a measure of market risk of a portfolio. The purpose of this article is to provide a VaR model for foreign-asset portfolios in continuous time. In the VaR model, the VaRs are not only a function of volatilities of asset returns and exchange rate but also a function of correlation coefficient between foreign assets and exchange rate. Moreover, by backtesting, the empirical results show that the new VaR model can efficiently evaluate the market risk of foreign-asset portfolios.     

Systematic skewness in asset pricing: an empirical examination of the Taiwan stock market

This paper is an empirical study of asset pricing with the systematic skewness in the pricing model. We adopt the Fama-French three-factor model, which incorporates the firm-size and book-to-market ratio in asset pricing as the base case, and then includes the skewness factor used by Harvey and Siddique in the pricing model. The evidence shows that systematic skewness is significant and might be important in asset pricing when portfolios are formed by industry, firm-size, book-to-market, or momentum strategies. When portfolios are constructed by momentum or coskewness strategies, lower momentum, or lower coskewness portfolios exhibit higher skewness and higher kurtosis. When portfolios are grouped by excess returns, it is seen that the average excess return is positively correlated with size and coskewness. Thus the systematic skewness is closely related to firm size. And the relationship between systematic skewness and excess return is obscured by the reverse firm-size effect.     

不完全市场、惩罚函数及一般均衡

不完全市场一般均衡分析框架使我们更加了解现实金融市场中资产价格的形成机制,使用带有惩罚函数的同伦跟踪算法计算不完全市场经济一般均衡模型均衡(GEI),有效地克服了由于市场不完全引起的消费者资产组合无限扩张和需求函数不连续等传统GEI模型计算所固有的困难.     

Should we write prenuptial contracts?

A successful marriage requires for both parties to make investments in their relationship and marital assets. How such assets would be divided if and when the parties divorce is an important factor determining each party's ex ante investment incentives. Using the incomplete contracting approach, we characterize the optimal asset division rule, one that provides the parties with the best investment incentives. We then discuss the circumstances under which the spouses would agree, in equilibrium, to contract out state-imposed rules governing the allocation of marital assets upon divorce. We conclude by exploring the implications of our results in the context of various asset division rules currently discussed by policy-makers.     

The Impact of SFAS No. 157 on Commercial Banks

During 2008, U. S. banks were mired in a credit crisis. According to a group of economists and bankers, one cause of the 2008 credit crisis was an accounting rule termed mark-to-market. This rule required banks to write down large portions of their investment portfolios. The purpose of this study is to examine the impact of the mark-to-market model on a sample of banks for the first three quarters of the year 2008. Results indicated that while banks grew by 20% over time, the percentage of assets measured at fair value rose only slightly. Additionally, the results indicated that applying the mark-to-market rule did not reduce the regulatory capital position of banks.     

Bank profitability and macroeconomic conditions: Are business models different?

The paper investigates the impact of macroeconomic conditions on the profitability of EU banks by testing for differential effects according to the business model. We group banks into three business models using a hierarchical cluster analysis and find that using clusters based on the share of assets invested in loans reveals heterogeneity in the sensitivity of bank profitability to economic growth across business models. Our main result is that GDP growth, credit growth, and the risk-free yield curve influence profitability as expected, but we also find that the effect of GDP growth is only significant for banks that have a high and medium share of assets invested in loans, and not for banks that hold large portfolios of securities. This difference depends on the impact of growth on asset write downs, especially those on loans and, to a lesser extent, on revenues. The results suggest that studies relating bank profitability to macroeconomic conditions should take the heterogeneity of business models into account.     

The Influence of Different Investment Horizons on Risk Behavior

For longer investment periods, investment consultants usually recommend a larger proportion of risky assets for investor portfolios. We examine the effect of different investment horizons on investors' risk behavior. We are interested both in participants' risk perceptions and in their asset allocation behavior. We find significant underestimations of long-term risks, which lead to a higher proportion of risky assets in the long-term portfolios. Our data show that the belief in mean reversion is a potential explanation for this behavior.     

PORTFOLIO BEHAVIOUR AND ASSET PRICING IN A CHARACTERISTICS FRAMEWORK

We have applied the characteristics model to the problem of portfolio behaviour and asset pricing. By defining assets in terms of characteristics, we generated individual demands for assets which depended on the prices of assets, the technological relationship between assets and asset characteristics, and the individual's preferences for different characteristics. In general, the characteristics model cannot be readily aggregated across individuals. However, when we assumed that the assets-characteristics technology had a simple form which was common to all individuals, market-clearing conditions could be used to derive an asset pricing model. Finally, we showed that the characteristics model provides a unified approach to the problem of preference-based portfolio behaviour and asset pricing. A number of existing models can be interpreted as characteristics models: the state-preference model, the parameter-preference model, the capital asset pricing model and the inter-temporal capital asset pricing model.     

A large CVaR-based portfolio selection model with weight constraints

Although the traditional CVaR-based portfolio methods are successfully used in practice, the size of a portfolio with thousands of assets makes optimizing them difficult, if not impossible to solve. In this article we introduce a large CVaR-based portfolio selection method by imposing weight constraints on the standard CVaR-based portfolio selection model, which effectively avoids extreme positions often emerging in traditional methods. We propose to solve the large CVaR-based portfolio model with weight constraints using penalized quantile regression techniques, which overcomes the difficulties of large scale optimization in traditional methods. We illustrate the method via empirical analysis of optimal portfolios on Shanghai and Shenzhen 300 (HS300) index and Shanghai Stock Exchange Composite (SSEC) index of China. The empirical results show that our method is efficient to solve a large portfolio selection and performs well in dispersing tail risk of a portfolio by only using a small amount of financial assets.     

Energy portfolio risk management using time-varying extreme value copula methods

This work is concerned with the statistical modeling of the dependence structure between three energy commodity markets (WTI crude oil, natural gas and heating oil) using the concept of copulas and proposes a method for estimating the Value at risk (VaR) of energy portfolio based on the combination of time series models with models of the extreme value theory before fitting a copula. Each return series is modeled by AR-(FI) GARCH univariate model. Then, we fit the GPD distribution to the tails of the residuals to model marginal residuals distributions. The extreme value copula to the iid residuals is fitted and we simulate from it to construct N portfolios and estimate VaR. As a first step, the method is applied to a two-dimensional energy portfolio. In second step, we extend method in trivariate context to measure VaR of three-dimensional energy portfolio. Dependences between residuals are modeled using a trivariate nested Gumbel copulas. Methods proposed are compared with various univariate and multivariate conventional VaR methods. The reported results demonstrate that GARCH-t, conditional EVT and FIGARCH extreme value copula methods produce acceptable estimates of risk both for standard and more extreme VaR quantiles. Generally, copula methods are less accurate compared with their predictive performances in the case of portfolio composed of exchange market indices.     

Asset arbitrage and the price of oil

It is commonly understood that macroeconomic shocks influence commodity prices and that one channel for this is the link between interest rates, expected future asset returns and stock-holding. In this paper the link is extended to the petroleum market with the recognition that recorded stocks of oil comprise a small share of annual demand and that the parallel with storable commodities is the decision to produce the oil in the first place, as opposed to holding it in the ground as reserve. Oil reserves are then a key asset in producing countries, which is arbitraged against financial assets. Thus, when the yield on financial assets falls, retaining oil reserves becomes more attractive to producing countries, which then have less incentive to accommodate demand rises, and so the oil price rises. This perspective on oil pricing is modeled in a dynamic multi-region general equilibrium framework in which regional households manage portfolios of assets that include oil reserves. When the model is calibrated to match observed data over two decades, simulation results indicate that asset arbitrage made a large contribution to the high pre-GFC oil price.     

艺术品的金融属性：投资收益与资产配置*

本文基于2000—2014年中国艺术品拍卖市场近现代国画的微观数据,在资产配置中引入市场交易机制中的佣金变量,加入艺术品市场规模约束,采用重复交易法实证计量嵌入艺术品市场的投资收益特征并量化其资产配置效应,以测度其市场功能。优质的艺术精品具备金融资产风险和收益的基本特征,本文对艺术品资产与资本资产定价模型的适应性进行讨论。研究表明：在样本期内,剔除通胀和佣金成本因素后收益率更加贴近现实,中国艺术品投资的实际收益率水平为1308%,表现出高于欧美市场的投资溢价;艺术品投资与传统的股票、债券等金融资产之间表现出相对独立性,并能有效改善投资者资产组合的风险边界,可以成为资产配置优化和多样化的重要选择。中国艺术品市场的长期稳健发展将为投资者提供更多的资产优化产品和工具。     

消费习惯、异质偏好与动态资产定价:纯交换经济情形

本文用Chan和Kogan、Bask和Cuoco等的方法考虑纯交换经济下的定价问题,我们引进了两个投资者:一个具有外在性消费习惯;一个不具有消费习惯。我们重点考察消费习惯对投资者的最优消费规则的影响以及对资产价格的确定。此外,我们还考虑了对数效用函数下,消费习惯以差的形式出现的情形下的消费规则和定价问题。我们发现当两个投资者中一个具有消费习惯而另一个不具有该习惯时,消费习惯同时改变两个投资者的最优消费规则、消费动态和财富动态。此时的动态资产定价受外在性消费习惯的影响,即时Sharpe比为常数,并等于同质量经济下的即时Sharpe比。同时,如果考虑对数效用函数下消费习惯以差的形式出现,则即时Sharpe比是时变的,反周期的。