A note on diversification and the reduction of dispersion

The purpose of this paper is to note that the question of optimal diversification cannot be answered simply by determining the average variability of equally allocated investment. Empirical results are presented which show that it is possible to obtain the same level of average variation with far greater average portfolio returns and fewer securities in the portfolio by using an alternative allocation scheme.     

Possibility versus feasibility: International portfolio diversification under financial liberalization

Financial liberalization may have double-edged impacts on international portfolio diversification since it increases financial market integration and market correlation simultaneously. Financial market integration enhances the possibility of diversifying portfolios internationally, while financial market correlation reduces the feasibility of such a diversification benefit. Using a dataset of stock market across 35 countries over the period 2001–2021, this paper examines the “possibility versus feasibility” puzzle arising from international portfolio diversification under financial liberalization. The empirical results show that financial liberalization has a positive (negative or no) impact on diversification benefits in its early (medium or developed) stage respectively due to its dual effects. Moreover, market integration positively affects diversification benefits only in the early stage of financial liberalization, while market correlation consistently has a negative impact on diversification benefits. Furthermore, this paper proposes an integration-correlation-oriented (ICO) diversification strategy to address the “possibility versus feasibility” puzzle, enabling international investors to make appropriate decisions on international portfolio diversification under financial liberalization.     

Benefits of international diversification with investment constraints: An over-time perspective

This paper investigates the benefits and asset allocation of the optimal international diversification for the U.S.A. investor while considering various portfolio constraints. Although the global financial market is becoming more integrated, the findings suggest that adding lower and upper weighting bounds reduces, but does not completely eliminate, the potential economic value of international investment. The addition of investment constraints makes asset allocation more feasible and decreases the volatility in portfolio return. The time-variation in the optimal asset allocation implies that fund managers should rebalance international portfolios dynamically. The out-of-sample test suggests that the Markowitz model with constraints realizes trivial improvement in mean-variance efficiency but still demonstrates significant reduction in risk.     

International diversification with securitized real estate and the veiling glare from currency risk

This paper analyzes diversification benefits from international securitized real estate in a mixed-asset context. We apply regression-based mean-variance efficiency tests, conditional on currency-unhedged and fully hedged portfolios to account for systematic foreign exchange movements. From the perspective of a US investor, it is shown that, first, international diversification is superior to a US mixed-asset portfolio, second, adding international real estate to an already internationally diversified stock and bond portfolio results in a further significant improvement of the risk-return trade-off and, third, considering unhedged international assets could lead to biased asset allocation decisions not realizing the true diversification benefits from international assets.     

Does a Held-to-Maturity Strategy Impede Effective Portfolio Diversification for Islamic Bond (Sukuk) Portfolios? A Multi-Scale Continuous Wavelet Correlation Analysis

There is a critical gap in the literature in studying the portfolio diversification opportunities available to sukuk investors and evaluating these in light of held-to-maturity strategies usually adopted by these investors. This article has made an initial attempt to study the portfolio diversification strategies for sukuk portfolios across heterogeneous investment horizons. Our findings critically indicate that returns between local currency sukuk in different markets generally have low levels of correlations across different investor holding periods, thus enabling both short and long-run portfolio diversification benefits. However, in contrast, international currency sukuk issued in different markets exhibits high levels of correlations in the longer-term investor holding periods. Also, in the domestic market context, returns on different classes of domestic sukuk are found to exhibit strong correlations in the longer-holding periods. Our findings critically highlight the feasibility of held-to-maturity sukuk investment strategies from a portfolio diversification perspective.     

Which market integration measure?

This paper compares the dynamics of the financial integration process as described by different empirical approaches. To this end, a wide range of measures accounting for several dimensions of integration is employed. In addition, we evaluate the performance of each measure by relying on an established international finance result, i.e., increasing financial integration leads to declining international portfolio diversification benefits. Using monthly equity market data for three different country groups (i.e., developed markets, emerging markets, developed plus emerging markets) and a dynamic indicator of international portfolio diversification benefits, we find that (i) all measures give rise to a very similar long-run integration pattern; (ii) the standard correlation explains variations in diversification benefits as well or better than more sophisticated measures. These findings are robust to a battery of robustness checks.     

Portfolio Diversification Benefits at Different Investment Horizons During the Arab Uprisings: Turkish Perspectives Based on MGARCH–DCC and Wavelet Approaches

This study is an initial attempt at investigating the extent to which portfolio diversification benefits at different investment horizons are available to a Turkish investor from investment in MENA countries exposed to the Arab spring based on MGARCH-DCC and Wavelet techniques on daily data spanning from 2005 to 2015. The findings tend to suggest that the Turkish investors may not benefit from investment in Egypt for almost all investment horizons but may have moderate benefits from Lebanon up to the investment horizons of 32–64 days and longer. However, Turkish investors may benefit from Oman excepting the longer investment horizons. In the long run, all stock holding periods exceeding 32 days have minimal benefits for portfolio diversification.     

Efficient Option Replication in the Presence of Transactions Costs

In the presence of transaction costs, a risk-return trade-off exists between the quality and the cost of a replicating strategy. In that context, I show how to expand the set of all possible time-based strategies through the introduction of a multi-scale class of strategies, which consist in rebalancing different fractions of an option portfolio at different time frequencies. The method, based on time-scale diversification, is to dynamic replication what investment in diversified portfoliosis to static portfolio selection: in a dynamic context, one may enjoy the benefits of diversification by using different time scales in trading the same asset. This revised version was published online in November 2006 with corrections to the Cover Date.     

Equity Home‐Bias: A Suboptimal Choice for UK investors?

In spite of the popularity of international portfolio diversification theory, extant empirical literature shows that investors prefer domestic assets and as a result, many studies argue that investors' portfolios are largely suboptimal. This paper examines whether British investors need to diversify their portfolios internationally to gain performance benefits from international markets or can they obtain these benefits by mimicking the portfolios with domestically traded assets. The results confirm that it is possible to mimic the performance of foreign equity with domestic equity. Indeed, the pay‐offs from homemade portfolios outperform those from international portfolios regardless of the periodic variation in the overall performance of the UK market vis‐à‐vis foreign markets. The superiority of homemade portfolio is more prominent in recent years and is enhanced by the increased internationalisation of developed capital markets. Therefore, investors' home bias is not suboptimal.     

Farmland Investment Under Conditions of Certainty and Uncertainty

This study investigates the potential for farmland to improve mixed-asset portfolio efficiency. Three major conclusions are drawn from the research. First, in a world with certainty, farmland can be shown to statistically improve mixed-asset portfolio efficiency. Second, with the introduction of uncertainty into the portfolio allocation model, investors can justify small or no allocations of farmland in a mixed-asset portfolio, although it appears that even with uncertainty prudent investors should evaluate the asset class. Third, with respect to farmland investment and geographic diversification, the results question the ability of an optimized mean–variance portfolio to provide substantial improvement in comparison to a naïve portfolio. The marginal improvement in portfolio efficiency of an optimized farmland portfolio versus a naïve farmland portfolio is not statistically significant.     

International Portfolio Investment: Theory, Evidence, and Institutional Framework

At first sight, the idea of investing internationally seems exciting and full of promise because of the many benefits of international portfolio investment. By investing in foreign securities, investors can participate in the growth of other countries, hedge their consumption basket against exchange rate risk, realize diversification effects and take advantage of market segmentation on a global scale. Even though these advantages might appear attractive, the risks of and constraints for international portfolio investment must not be overlooked. In an international context, financial investments are not only subject to currency risk and political risk, but there are many institutional constraints and barriers, significant among them a host of tax issues. These constraints, while being reduced by technology and policy, support the case for internationally segmented securities markets, with concomitant benefits for those who manage to overcome the barriers in an effective manner.     

Do investors still benefit from culturally home-biased diversification? An empirical study of China, Hong Kong, and Taiwan

Due to the continual economic integration and the accumulation of wealth in China, Hong Kong, and Taiwan, understanding portfolio strategies and the benefits of diversification for these countries is an indispensible element in managing global assets. Using weekly industry-level data, we analyze culturally home-biased diversification strategies and find that local investors still benefit from regional investments. The time-varying benefits of diversification exist even as the economies of this region have become increasingly integrated. Our analysis suggests that stricter weighting bounds reduce the economic values of diversification but enhance the feasibility of the optimal portfolio allocations. The larger benefits gained by Chinese investors suggest that international diversification is more advantageous to investors in emerging economies than to those in richer, developed markets. The robustness tests generate similar findings when we evaluate the out-of-sample effectiveness and the benefits of diversification under various parameter estimation windows.     

Computing optimal rebalance frequency for log-optimal portfolios

Log-optimal investment portfolio is deemed to be impractical and cost-prohibitive due to inherent need for continuous rebalancing and significant overhead of trading cost. We study the question of how often a log-optimal portfolio should be rebalanced for any given finite investment horizon. We develop an analytical framework to compute the expected log of portfolio growth when a given discrete-time periodic rebalance frequency is used. For a certain class of portfolio assets, we compute the optimal rebalance frequency. We show that it is possible to improve investor log utility using this quasi-passive or hybrid rebalancing strategy. Simulation studies show that an investor shall gain significantly by rebalancing periodically in discrete time, overcoming the limitations of continuous rebalancing.     

An empirical examination of the benefits of international diversification

We examine the benefits of international portfolio diversification for U.K. investors between January 1985 and December 2000 using the approach of Wang [Wang, Z., 1998. Efficiency loss and constraints on portfolio holdings. Journal of Financial Economics 48, 359–375] and Li et al. [Li, K., Sarkar, A., Wang, Z., 2003. Diversification benefits of emerging markets subject to portfolio constraints. Journal of Empirical Finance 10, 57–80]. We find significant increases in the Sharpe [Sharpe, W.F., 1966. Mutual fund performance. Journal of Business 39, 119–138] and certainty equivalent return (CER) performance in moving from a domestic strategy to an international strategy that includes either global industry or country equity portfolios, even in the presence of short selling restrictions. We also find significant diversification benefits using U.K. unit trusts with international equity objectives. However, U.K. international unit trusts do not capture all the diversification benefits provided by either global industry or country equity portfolios.     

Maximizing an equity portfolio excess growth rate: a new form of smart beta strategy?

It has been claimed that, for dynamic investment strategies, the simple act of rebalancing a portfolio can be a source of additional performance, sometimes referred to as the volatility pumping effect or the diversification bonus because volatility and diversification turn out to be key drivers of the portfolio performance. Stochastic portfolio theory suggests that the portfolio excess growth rate, defined as the difference between the portfolio expected growth rate and the weighted-average expected growth rate of the assets in the portfolio, is an important component of this additional performance (see Fernholz [Stochastic Portfolio Theory, 2002 (Springer)]). In this context, one might wonder whether maximizing a portfolio excess growth rate would lead to an improvement in the portfolio performance or risk-adjusted performance. This paper provides a thorough empirical analysis of the maximization of an equity portfolio excess growth rate in a portfolio construction context for individual stocks. In out-of-sample empirical tests conducted on individual stocks from 4 different regions (US, UK, Eurozone and Japan), we find that portfolios that maximize the excess growth rate are characterized by a strong negative exposure to the low volatility factor and a higher than 1 exposure to the market factor, implying that such portfolios are attractive alternatives to competing smart portfolios in markets where the low volatility anomaly does not hold (e.g. in the UK, or in rising interest rate scenarios) or in bull market environments.     

International Asset Allocation With Regime Shifts

Correlations between international equity market returns tendto increase in highly volatile bear markets, which has led someto doubt the benefits of international diversification. Thisarticle solves the dynamic portfolio choice problem of a U.S.investor faced with a time-varying investment opportunity setmodeled using a regime-switching process which may be characterizedby correlations and volatilities that increase in bad times.International diversification is still valuable with regimechanges and currency hedging imparts further benefit. The costsof ignoring the regimes are small for all-equity portfoliosbut increase when a conditionally risk-free asset can be held.     

Optimal portfolio selection and compression in an incomplete market

We investigate an optimal investment problem with a general performance criterion which, in particular, includes discontinuous functions. Prices are modelled as diffusions and the market is incomplete. We find an explicit solution for the case of limited diversification of the portfolio, i.e. for the portfolio compression problem. By this we mean that any admissible strategy may include no more than m different stocks concurrently, where m may be less than the total number n of available stocks.     

International portfolio diversification benefits: Cross-country evidence from a local perspective

We investigate how the benefits of international portfolio diversification differ across countries from the perspective of a local investor. We find that the benefits of investing abroad are largest for investors in developing countries, including when controlling for currency effects. Most of the benefits are obtained from investing outside the region of the home country. These global diversification benefits remain large when controlling for short-sales constraints in developing stock markets. The gains from international portfolio diversification appear to be largest for countries with high country risk. In addition to this cross-sectional evidence, we also provide evidence that diversification benefits vary over time as country risk changes. We find that diversification benefits have decreased for most countries in our sample over the past two decades.     

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.     

Foreign Property Shocks and the Impact on Domestic Securitized Real Estate Markets: An Unobserved Components Approach

As the globalization of world financial markets continues unabated the issue of benefits arising from international diversification becomes increasingly important. Due to the fixed geographical nature of the underlying product, securitized property might be considered immune from the effects of globalization, and to this extent researchers have considered the issue of international property market interdependence using a variety of statistical procedures. In this paper the question of interdependence across securitized property markets is examined by combining the Inoue (1999) cointegration methodology with the structural time series procedure of Harvey (1989). In the event of commonality of movement across property markets, this approach permits the researcher to isolate and visualize common movement, an operation that may be helpful to a portfolio manager trying to understand cross market activity. The results indicate that there is some unifying force across international property markets and that this unifying force may stem from the United States. The results also suggest that, at least to some extent, shocks to securitized property markets produce a similar response to stock market shocks.