Optimal growth portfolios reconciling theory and practice

Modern portfolio theory dictates diversification among assets that are not perfectly correlated (that is, asset diversification). Professional investors, on the other hand, contend that one can simply diversify across time (that is, time diversification). The controversy of time diversification versus asset diversification is examined in this article by empirically analyzing the optimum investment strategies for a myopic utility function (the extreme case that supports across asset diversification) under varying degrees of relative risk aversion. While Merton and Samuelson (1974) and Samuelson (1990) show that with a myopic utility function the investment diversification strategy does not change with an increase in the investment horizon, the recommendation of professional investors is also found to hold since for a wide range of relative risk-aversion measures, the optimum portfolio is shown to consist almost entirely of equities.     

In search of safe haven assets during COVID-19 pandemic: An empirical analysis of different investor types

This study assesses the role of gold, crude oil and cryptocurrency as a safe haven for traditional, sustainable, and Islamic investors during the COVID-19 pandemic crisis. Using Wavelet coherence analysis and spillover index methodologies in bivariate and multivariate settings, this study examines the correlation of these assets for different investment horizons. The findings suggest that gold, oil and Bitcoin exhibited low coherency with each stock index across almost all considered investment horizons until the onset of the COVID-19. Conversely, with the outbreak of the pandemic, the return spillover is more intense across financial assets, and a significant pairwise return connectedness between each equity index and hedging asset is observed. Hence, gold, oil, and Bitcoin do not exhibit safe-haven characteristics. However, by decomposing the time-varying co-movements into different investment horizons, we find that total and pairwise connectedness among the assets are primarily driven by a higher-frequency band (up to 4 days). It indicates that investors have diversification opportunities with gold, oil, and Bitcoin at longer horizons. The results are robust over different types of equity investors (traditional, sustainable, and Islamic) and various investment horizons.     

Optimal holding period for assets that must be liquidated: A certainty equivalent wealth approach

Consumers often invest with a specific goal in mind and often know with some precision when the investment proceeds will be needed to achieve that goal. Because different investors have different attitudes toward risk and because different asset types exhibit different risk characteristics, there is often confusion as to the appropriate investment asset for a particular investor with a known investment horizon. It is also frequently, unclear as to whether investments should be switched to a less risky asset as time to liquidation becomes short. This paper addresses the issues of initial asset choice and the advisability of switching among assets when the investment goal date is known, employing the methodology of certainty equivalent wealth. In addition to suggesting optimal investment strategies for individuals based upon holding period and degree of risk aversion, it shows that switching investment assets produces suboptimal results.     

Risk diversification gains from metropolitan housing assets

The study analyzes the roles of metropolitan housing assets in risk diversification by assessing intertemporal hedging demands for multi‐asset portfolios, which include metropolitan houses, REITs, stocks, bonds, and riskless assets. Investors substitute housing assets in high‐population MSAs with those in low‐population cities, and they switch their holdings of housing assets to less risky bonds in the 2007–2008 housing bust. The findings from the multi‐period portfolio choice problem provide evidence for momentum reversal since forward‐looking investors substitute bottom metropolitan housing assets for top ones in the housing boom, and the GTTB index and the lagged REIT price return have negative impacts on various asset returns.     

The Role of Real Estate in an Institutional Investor's Portfolio Revisited

Many papers have recently pointed out that institutional investors allocate only a very small fraction of their portfolio to real estate, much smaller than theory would dictate. This raises the question, are institutional investors underinvested in real estate equities? Or do we simply have the wrong priors? This paper is an attempt to provide some new insights into this asset allocation paradox. The key conclusions of the paper are several: First, unlike other assets, it would appear that real estate, and real estate diversification, pays off at the very time when the benefits are most needed, that is, when consumption growth opportunities are low. Second, real estate returns are predictable. In fact, the amount of predictability in real estate returns appears to be about the same as in stock returns. Third, real estate performs well in an asset-liability framework. Fourth, the chance of experiencing a large loss on real estate over a long horizon is quite small. We also report here that private sector commercial real estate investments represent between 6 and 12 percent of investable wealth in the United States. Thus, it follows (if one believes the capital asset pricing model) that if institutional investors were to invest more in real estate (up to 12 percent of their assets), they should be able to eliminate nonmarket or unique risk. All of this leaves us a bit dumbfounded as to why institutional investors hold only between 2 and 3 percent of their assets in real estate.     

Long-term U.S. infrastructure returns and portfolio selection

Our understanding of the long-term return behavior and portfolio characteristics of public infrastructure investments is limited by a relatively short history of empirical data. We re-construct U.S. listed infrastructure index returns by mapping their monthly performance to received systematic and industry risk factors from 1927 through 2010. Our findings reveal that the infrastructure returns in recent years may understate the tail-risk that investors could experience over the long-term, however, this tail-risk is commensurate with holding a broad portfolio of U.S. stocks. For mean-variance and mean-CVaR investors, we report the benefits of holding public infrastructure assets in investment portfolios.     

Correlation risk

Investors hold portfolios of assets with different risk-reward profiles for diversification benefits. Conditional on the volatility of assets, diversification benefits can vary over time depending on the correlation structure among asset returns. The correlation of returns between assets has varied substantially over time. To insure against future “low diversification” states, investors might demand securities that offer higher payouts in these states. If this is the case, then investors would pay a premium for securities that perform well in regimes in which the correlation is high. We empirically test this hypothesis and find that correlation carries a significantly negative price of risk, after controlling for asset volatility and other risk factors.     

International capital market equilibrium with investment barriers

This paper outlines models of capital market equilibrium when there are explicit barriers to international investment in the form of a tax on holdings of assets in one country by residents of another country. There is a corresponding subsidy on short positions in foreign assets. Asset prices deviate from the predictions of the world capital asset pricing model. Investors do not hold a mixture of national market portfolios, but the mix of risky assets is the same for every investor in a country. Optimal portfolios tend to be heavy in domestic assets, and light in foreign assets. Tax free investors, however, tend to hold assets anywhere in the world that are taxed heavily. Estimates of the magnitude of the average tax (or the magnitude of effective barriers to international investment) can be made by comparing the average return on the minimum variance zero β portfolio, z, with the average across countries and time of the short-term interest rate. When barriers are ineffective, the expected return on portfolio z will be the average short-term interest rate, and the world capital asset pricing model will hold.     

DO INSTITUTIONAL INVESTORS IN THE UK ADOPT A DUAL STRATEGY FOR MANAGING FOREIGN EXCHANGE RISK?

In recent years, the gradual increase in international portfolio diversification within the UK institutional investment community has led to a growing need to manage foreign exchange (FX) risk. This paper reports on the findings of a postal questionnaire survey relating to FX risk management practices in UK institutional investment organisations. The findings demonstrate an increasing awareness of the FX risk management problem and indicate that UK investment institutions actively manage FX risk within their investment portfolios. The paper also focuses on the interesting question of whether UK institutional investors manage their own portfolio's FX risk, simultaneously concerning themselves with their investee companies’ FX risk management practices. Overall, the findings indicate that institutional investors adopt adual strategyfor managing FX risk; not only managing their own FX risk, but also requiring that their investee companies manage FX risk. There is also evidence to suggest that the institutional investors require their investee companies to disclose information relating to their FX risk management policies.     

上山下乡经历与家庭风险金融资产投资——基于断点回归的证据

本文使用中国家庭追踪调查(CFPS)2010年家庭和个人层面数据,考察了户主的上山下乡经历对于家庭风险金融资产投资决策的影响。结果表明,上山下乡经历显著提高了家庭对于股票及广义风险金融资产的投资概率和投资规模。机制分析表明,此经历主要通过提升家庭投资的风险偏好和投资能力来影响家庭的风险金融资产投资。分样本讨论结果表明,上山下乡经历对家庭风险金融投资产生的正向影响在高人力资本、高收入和高社会资本群体中更为显著。     

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.     

Conditions Ensuring the Decomposition of Asset Demand for All Risk-Averse Investors

Abstract

The paper explores how the demand for a risky asset can be decomposed into an investment effect and a hedging effect by all risk-averse investors. This question has been shown to be complex when considered outside of the mean-variance framework. Dependence among returns on the risky assets is restricted to quadrant dependence and it is found that the demand for one risky asset can be decomposed into an investment component based on the risk premium offered by the asset and a hedging component used against the fluctuations in the return on the other risky asset. The paper also discusses how the class of quadrant-dependent distributions is related to that of two-fund separating distributions. This contribution opens up the search for broader distributional hypotheses suitable to asset demand models. Examples are discussed.     

Systemic Liquidation Risk and the Diversity–Diversification Trade‐Off

This paper proposes a portfolio choice model in which investors are subject to liquidation risk and (endogenously) face higher costs in the event of joint liquidation (as was observed during the crisis of 2008 to 2009). The risk of joint liquidation creates an incentive for investors to choose heterogeneous portfolios and to rationally forgo diversification benefits. Joint liquidation risk is also reflected in asset prices, resulting in (1) assets with high idiosyncratic risk having low expected returns, and (2) assets that display high correlation with the portfolios of (liquidation‐prone) investors having high expected returns.     

Optimal Decentralized Investment Management

We study an institutional investment problem in which a centralized decision maker, the Chief Investment Officer (CIO), for example, employs multiple asset managers to implement investment strategies in separate asset classes. The CIO allocates capital to the managers who, in turn, allocate these funds to the assets in their asset class. This two-step investment process causes several misalignments of objectives between the CIO and his managers and can lead to large utility costs for the CIO. We focus on (1) loss of diversification, (2) unobservable managerial appetite for risk, and (3) different investment horizons. We derive an optimal unconditional linear performance benchmark and show that this benchmark can be used to better align incentives within the firm. We find that the CIO's uncertainty about the managers' risk appetites increases both the costs of decentralized investment management and the value of an optimally designed benchmark.     

The Effect of Serial Dependence on Multiperiod Holding Period Return Performance

The impact of the investment time horizon on risk‐return properties of asset returns depends on the presence of serial correlation and higher order serial dependencies. We present a methodology for decomposing multiperiod holding period return covariance into serial and cross‐sectional components using a recursive multiplicative model that captures the effects of serial and cross‐sectional dependencies and their joint effects without requiring a distributional form assumption. Applying this model to historical monthly return series for commonly held financial assets and portfolios of assets, we investigate the significance of the investment time horizon, the existence and relevance of time diversification, the inflation‐hedging effectiveness of different assets, and the appropriateness of applying traditional capital market theory in a multiperiod framework.     

新会计准则下银行资产分类会计选择的理论建模

2007年1月1日起实施的新会计准则对商业银行最重要的影响在于资产分类方面的新规定。新准则规定基于管理者持有该证券的动机和是否具有持有到期的能力对金融资产分类。资产分类的不同决定着市场价值变化对盈利水平和银行权益的影响。本文考虑新会计准则对银行资产分类的可能影响,设计了一个债券类产品和贷款,根据投资者效用和动机研究银行的资产分类决策,对银行考虑新会计准则对其影响时的资产分类决策建模。模型的解表明,风险中性的银行权衡流动性需求、权益稳定、资产收益几个方面决定其金融资产的分类,而银行收益和股东价值仍主要取决于银行的投资战略和对市场的预期,对资产分类规定的变化不会影响银行的实际收益,但短期银行会考虑其流动性需求和监管资本的稳定性,来决定银行的分类决策。     

机构投资对我国资本市场资产价格影响的实证研究

本文以1999年3月到2011年3月的沪深主板上市公司月收益率为样本,通过定义机构投资者的投资策略,对加入机构投资者影响后的CAPM扩展模型进行实证研究,发现扩展模型消除了经典CAPM中存在的异方差性,且不存在一阶自相关性;资产组合的收益率同市场组合收益率呈反比关系,与基准投资组合收益率呈正比关系;模型拟合度有了很大的改善。机构投资对我国资本市场资产价格产生了积极的影响。因此,我国资本市场应该大力发展机构投资者,机构投资者本身也应该朝着健康的方向发展。     

Does institutional ownership matter for international stock return comovement?

We study the link between international stock return comovements and institutional investment. We test whether the rise of institutional ownership has increased cross-country correlations and decreased cross-industry correlations. Using stock-level institutional holdings across 45 countries during the 2001–2010 period, we find that industry and global factors are relatively more important the country factors in explaining stock return variation among stocks with higher institutional ownership. Industry diversification strategies are more beneficial than country diversification strategies for stocks with high institutional ownership. We show that cross-border portfolio investment is a powerful force of international capital market integration and convergence of asset prices.     

The impact of idiosyncratic risk on corporate financialisation——Evidence from China

Using the quarterly data of non-financial companies listed on China's A-share market from 2007 to 2019, this paper examines the relationship between the idiosyncratic risk formed based on the secondary market exchanges and the corporate financialization from the perspective of a market feedback effect. The empirical results show that idiosyncratic risk has a significant impact on the allocation of financial assets of non-financial enterprises, which is one of the motivating factors for the financialization of non-financial enterprises. Compared with SOEs, large enterprises and non-manufacturing enterprises; private enterprises, small and medium-sized enterprises, and manufacturing enterprises will allocate more financial assets when idiosyncratic risk increases. Mechanism analysis shows that managers risk aversion and financing constraints increase the impact of idiosyncratic risk on financial asset allocation while strengthening the external monitoring mechanism of institutional investors has the opposite effect. The research findings of this paper help to understand whether secondary financial markets affect the financial investment decisions of real firms in transition economies, and also have implications for how to govern the “transition from real to virtual” of real enterprises in China.     

Static and dynamic connectedness between NFTs,Defi and other assets: Portfolio implication

The paper examines the return and volatility transmission between NFTs, Defi assets, and other assets (oil, gold, Bitcoin, and S&P 500) using the TVP-VAR framework. The results report weak static return and volatility spillovers between NFTs and Defi assets and selected markets, showing that these new digital assets are still relatively decoupled from traditional asset classes. Bitcoin, oil, and half of the NFTs and Defi assets are net transmitters of return and volatility spillovers, whereas rest of the markets are net recipients of spillovers. Our findings show that the dynamic return and volatility connectedness become higher during the initial phase of the COVID-19 pandemic and the cryptocurrency bubble of 2021. We also compute the static and dynamic optimal weights, hedge ratios, and hedging effectiveness for the portfolios of NFTs/other asset and Defi asset/other asset and show that investors and portfolio managers should consider adding NFTs and Defi assets in their portfolios of gold, oil, and stock markets to achieve diversification benefits.