Diversification and systemic risk

Portfolio diversification makes investors individually safer but creates connections between them through common asset holdings. Such connections create “endogenous covariances” between assets and investors, and enhance systemic risk by propagating shocks swiftly through the system. We provide a theoretical model in which shocks spread through constrained selling from N diversified portfolio investors in a network of asset holdings with home bias, and study the desirability of diversification by comparing the multivariate distribution of implied losses for every level of diversification. There may be a region on the parameter set for which the propagation effect dominates the individually safer one. We derive analytically the general element of the covariance between two assets i and j. We find agents may minimize their exposure to endogenous risk by spreading their wealth across more and more distant assets. The resulting network enhances systemic stability.     

Downside risk in Dow Jones Islamic equity indices: Precious metals and portfolio diversification before and after the COVID-19 bear market

Besides great turmoil in financial markets, the COVID-19 pandemic also disrupted the global supply chain, putting the precious metal market into great uncertainty. In this study, we revisit the diversifying role of precious metals – gold, silver, and platinum – for six Dow Jones Islamic (DJI) equity index portfolios using a battery of tests: dynamic conditional correlations (DCCs), four-moment modified value at risk (VaR) and conditional VaR, and global minimum-variance (GMV) portfolio approach. Our empirical results exhibit drastically increased DCCs between sample assets during the COVID period; however, pairing gold with any of the DJI equity indices (except for the Asia-Pacific region) decreases the downside risk of these portfolios. Other precious metals (silver and platinum) do not provide such benefits. Furthermore, we find that a higher allocation of wealth in DJI Japanese equities and gold is required to achieve a GMV portfolio in the post-COVID-19 era, implying higher transaction (hedging) costs to rebalance portfolios (weights) accordingly. Our out-of-sample tests examining the global financial crisis, European debt crisis, and extended sample (2000–2020) periods yield similar findings as gold glitters across all market conditions. Overall, our findings provide notable practical implications for both domestic and international investors.     

Commodity financialization and sector ETFs: Evidence from crude oil futures

We investigate the diversification benefits of energy assets in the setting of commodity financialization using data on crude oil futures and Sector ETFs (SPDRs). Correlations between commodities and financial assets increased during the post-Commodity Futures Modernization Act (CFMA)/commodity bull cycle period, resulting in lower benefits of diversification. However, we find that conditional correlations between crude oil futures and sector ETFs meaningfully increased only since the 2008–09 financial crisis. The results therefore suggest that the financial crisis, rather than CFMA regulation, explains changes in the diversification benefits of commodities. Moreover, we find that oil futures returns are less correlated with SPDRs than with the S&P index. Thus, energy futures, and crude oil in particular, offer the potential for diversification benefits in sector-style investing.     

Should investors include Bitcoin in their portfolios? A portfolio theory approach

Many papers in recent years have examined the benefits of adding alternative assets to traditional portfolios containing stocks and bonds. Bitcoin has emerged as a new alternative investment for investors which has attracted much attention from the media and investors alike. However relatively little is known about the investment benefits of Bitcoin and therefore this paper examines the benefit of including Bitcoin in a traditional benchmark portfolio of stocks and bonds. Specially, we employ data up to June 2018 and analyse the potential out-of-sample portfolio benefits resulting from including Bitcoin in a stock-bond portfolio for a range of eight popular asset allocation strategies. The out-of-sample analysis shows that, across all different asset allocation strategies and risk aversions, the benefits of Bitcoin are quite considerable with substantially higher risk-adjusted returns. Our results are robust to rolling estimation windows, the incorporation of transaction costs, the inclusion of a commodity portfolio, alternative indices, short-selling as well as two additional optimization techniques including higher moments with (and without) variance-based constraints (VBCs). Therefore, our results suggest that investors should include Bitcoin in their portfolio as it generates substantial higher risk-adjusted returns.     

Equity premium prediction and the state of the economy

We detect cyclical variation in the predictive information of economic fundamentals, which can be used to substantially improve and simplify out-of-sample equity premium prediction. Economic fundamentals based on stock-specific information (notably the dividend yield) deliver better predictions in expansions. Economic fundamentals based on aggregate information (notably the short rate) deliver better predictions in recessions. Accordingly, a simple forecast combination of one predictor that generates cyclical forecasts and one predictor that generates countercyclical forecasts can deliver statistically significant and economically valuable equity premium predictions in both expansions and recessions. A prominent two-predictor forecast combination that performs well is the dividend yield and the short rate. Strategies designed for ex-ante timing of the business cycle can provide additional economic gains in equity premium prediction.     

Lodging REITs and third-party operators: Do more operators enhance the performance of REITs?

Lodging REITs are required to hire unaffiliated third-party operators to manage their properties. It has been noted that some lodging REITs use only one operator, whereas others hire a number of different operations. However, why lodging REITs choose to hire one or more operators has not been verified yet. Accordingly, this study intended to examine whether hiring more operators (i.e., operator diversification) affects the performance of lodging REITs. The results of this study showed that diversifying third-party operators has a curvilinear relationship with firm performance. Furthermore, the curvilinear relationship can weaken when operator diversification is paired with geographic diversification, but the relationship does not change depending on segment or brand diversification. This study implies that it is critical to understand not only the appropriate number of operators but also how to combine diversification strategies to ensure the success of lodging REITs.     

协同创新网络成员多样性如何影响企业探索式创新——技术多元化的中介效应

运用协同创新和三螺旋等理论,划分协同创新网络成员多样性及其维度。以452家中国制造业高技术上市公司为样本,研究协同创新网络成员多样性与企业探索式创新的直接关系,并探讨技术多元化在两者间的中介作用。结果表明,协同创新网络成员主体多样性和区域多样性均显著正向影响探索式创新,技术多元化在主体多样性与探索式创新间发挥完全中介作用,在区域多样性与探索式创新之间则发挥部分中介效应。     

Time–frequency quantile dependence between Bitcoin and global equity markets

In this paper, we examine return dependence between Bitcoin and stock market returns using a novel quantile cross-spectral dependence approach. The results suggest a right-tail (high return) dependence between Bitcoin and the stock markets in the long term and that said dependence decreases significantly from yearly to monthly investment horizons. Furthermore, right-tail dependence between Bitcoin and the US stock market is the strongest compared with other stock markets. We also extract information on the time-varying and time–frequency structure of co-movements between Bitcoin and the stock markets using wavelet-coherence analysis, the results of which suggest that the co-movement between Bitcoin and the US stock market is positive, whereas, for other stock markets, it is negative at certain frequencies and time periods. Overall, the findings highlight additional risk-management capabilities of Bitcoin according to different stock markets.     

中国艺术品投资收益:离岸与在岸市场的特征和互动

文物艺术品既是一个国家的历史印记和文化瑰宝,也是情感资产和动产。本文基于2000-2017年全球艺术品核心市场——北京、香港、纽约和伦敦核心拍卖行中国书画的微观数据,使用特征价格法构建全球中国艺术品市场价格指数,展示全球中国艺术品拍卖市场发展的全貌,同时创新性地使用重复交易数据探讨离岸和在岸中国艺术品市场投资特征和互动关系。研究表明:北京和香港市场作为中国艺术品最大的在岸和离岸拍卖市场价格相互联动,走势基本一致;艺术品财务收益和精神回报是艺术品投资收藏和消费的主要原因,不同市场间财务收益和风险分散的差异是艺术品市场资产配置和资金流动的动力;纽约和伦敦市场中国艺术品投资收益率低于北京和香港,香港是全球中国艺术品投资收益率最高的地区,重复交易中的北京-香港交易策略占优,离岸香港市场得天独厚的环境优势使香港中国艺术品市场未来发展前景可期。     

中间品进口多样化、企业创新与工资水平

基于2000-2006年中国制造业企业数据库以及进出口海关数据库的匹配数据引入企业创新机制效应检验中间品进口多样化的工资溢出效应。研究表明中间品进口多样化、企业创新均能显著提高企业的工资水平。进一步考察企业的出口状态、所有制结构及企业所属地区差异后发现中间品进口多样化对出口企业、外资企业以及东部地区企业的工资影响更为显著。分位数回归结果进一步显示中间品进口多样化及企业创新对工资分布高分位企业的工资影响更为显著。基于中介效应模型的传导机制检验，认为中间品进口多样化通过节约成本、提升生产率及企业创新影响中国制造业企业工资水平的利润共享机制存在。在控制成本效应及生产率效应两种机制之后，企业创新成为中间品进口多样化作用于企业工资的新机制。