Equity Portfolio Diversification Research Articles

Gender difference in equity portfolio diversification

This study provides compelling evidence that individual investors consistently maintain under-diversified portfolios, with female investors exhibiting significantly lower levels of diversification than their male counterparts. Analyzing a comprehensive dataset of retail investor trades, this study provides the first detailed examination of gender differences in trading activity, performance, and portfolio diversification. Performance, and diversification are systematically related to investor characteristics such as portfolio size, income, education, language, age, and investment experience. The result that increasing diversification improves performance for all investors corresponds with the fact that female investors are found to diversify less at the same time as they show a slightly lower aggregated performance than male investors.

Impacts of cross‐border equity portfolio flow and central bank transparency on financial development: The role of economic freedom and international bonds

AbstractWe investigate the effects of international equity portfolio diversification and central bank independence on financial development using panel data from 49 countries from 2001 to 2016. We find that international equity portfolio diversification improves financial development. We correspondingly examine potential factors through which international equity portfolio diversification may impact financial development and find that central bank transparency provides an important channel for improving financial development. We further find that the relationship between international equity portfolio diversification and financial development is sensitive to economic freedom. Concerning sequencing, we find that foreign equity and debt flow are complementary to financial system development. Our results are robust to endogeneity using the exogenous shock of the 2008 financial crisis. This study offers new empirical evidence on the relationship between international capital and financial development.

The Indirect Diversification Benefits of Investing in Japanese Firms: An Alternative Perspective

AbstractThis paper examines the role of firm-level multinationality in equity portfolio diversification for Japanese firms from 1998 to 2015. We use a unique multinationality dataset for constituents of the Nikkei 225 based on two measures of sales and subsidiaries. We employ an extended version of the traditional Capital Asset Pricing Model (CAPM) to analyse the exposure of firm returns to various geographical regions. There is evidence that firms are not influenced by the geographic regions where they report operations. The results also indicate that there are benefits from investing in Japanese multinationals but these benefits do not increase with increasing multinationality. A new category of firms is identified that may be beneficial to investors—firms that are influenced by a geographical region where they do not report sales or subsidiaries. This finding has far reaching implications for portfolio management. Investors must do more than analyse the international location of firm operations. They must analyse the geographical influences on firm returns. Existing studies fail to distinguish between these two criteria, assuming them to be the same. We find evidence to the contrary.

How Many Stocks Are Sufficient for Equity Portfolio Diversification? A Review of the Literature

Using extensive and comprehensive databases to select a subset of research papers, we aim to critically analyze previous empirical studies to identify certain patterns in determining the optimal number of stocks in well-diversified portfolios in different markets, and to compare how the optimal number of stocks has changed over different periods and how it has been affected by market turmoil such as the Global Financial Crisis (GFC) and the current COVID-19 pandemic. The main methods used are bibliometric analysis and systematic literature review. Evaluating the number of assets which lead to optimal diversification is not an easy task as it is impacted by a huge number of different factors: the way systematic risk is measured, the investment universe (size, asset classes and features of the asset classes), the investor’s characteristics, the change over time of the asset features, the model adopted to measure diversification (i.e., equally weighted versus optimal allocation), the frequency of the data that is being used, together with the time horizon, conditions in the market that the study refers to, etc. Our paper provides additional support for the fact that (1) a generalized optimal number of stocks that constitute a well-diversified portfolio does not exist for whichever market, period or investor. Recent studies further suggest that (2) the size of a well-diversified portfolio is larger today than in the past, (3) this number is lower in emerging markets compared to developed financial markets, (4) the higher the stock correlations with the market, the lower the number of stocks required for a well-diversified portfolio for individual investors, and (5) machine learning methods could potentially improve the investment decision process. Our results could be helpful to private and institutional investors in constructing and managing their portfolios and provide a framework for future research.

Equity Portfolio Diversification: How Many Stocks Are Enough? Evidence From India

How many stocks are required to reduce unsystematic risk significantly is an important question for investors. While there is a large body of research on the subject in the United States, there is little formal work on this question in India. We show that a 15-20 stock portfolio, the traditional market rule-of-thumb for a diversified portfolio, is likely inadequate to minimize unsystematic risk. We show that an investor could target to reduce diversifiable risk by 90% with a 90% confidence with a portfolio of 40-50 stocks. We build a practical framework that serves as a baseline for investors to target a specific reduction in diversifiable unsystematic risk at a chosen confidence level.

Does the Euro–Mediterranean Partnership contribute to regional integration?

The paper investigates whether Southern Mediterranean and Middle Eastern markets under the Euro–Mediterranean Partnership (Egypt, Lebanon, Morocco, Malta, and Turkey) have become more financially integrated with the European stock market over time. The findings suggest that the Turkish equity market is moderately integrated with the European market, while the other economies exhibit weak financial integration with Europe, supporting the idea that the partnership appears to have no effect on enhancing inter-market linkages for these economies. Therefore, these markets would be good destinations for international investors seeking attractive investment opportunities to diversify their equity portfolios. Structural changes in the cross-market integration do exist, which may be considered as a guide for international equity portfolio diversification over different subperiods. In addition, there is evidence of an increasing trend in conditional correlations for Egypt and Turkey, to varying degrees, over time, notably during the post global financial crisis of 2007–2008, thus revealing herding behavior during this period. Overall, investors should be wary of the variation of equity market integration over time before engaging in an investment at the level of portfolio management and diversification. Policymakers must be aware of the remoteness of the current achievements of the Euro–Mediterranean Partnership from the targets set in terms of financial development and economic growth.

Suboptimal international equity portfolio diversification and stock market development

This paper examines whether the widely reported phenomena of home and foreign biases (i.e. suboptimal international equity portfolio diversification) hold any ramifications for the development of stock markets. The results, analysed using macro- and micro-level data, support the view that stock markets that are characterised by a higher degree of home bias are associated with lower levels of development. On the other hand, markets where foreign investors show a higher degree of allocation preference, relative to the prescribed benchmark (foreign bias), are found to be more developed. The results, which are robust to the use of shock based identification strategy, indicate that policy measures that promote optimal international equity portfolio diversification could be crucial in developing the depth and breadth of domestic stock markets.

The changing role of emerging and frontier markets in global portfolio diversification

Although the literature on the benefits of diversifying equity portfolios to emerging markets is abundant, the role of frontier markets in global equity portfolio diversification is clearly less ex...

Time-Varying Linkages of Economic Activities in China and the Stock Markets in ASEAN-5

This study attempts to investigate the evolution of dynamic linkages and volatility spillover between the five countries of the Association of Southeast Asian Nations (ASEAN-5) stock markets and China’s economic activities. By using the movements and structural breaks of the time-varying correlation and Granger causality test, a suitable destination for equity portfolio diversification can be determined among the studied markets. This study covers monthly data from January 1991 to March 2015. The DCC-MGARCH model shows that the studied countries are time-varying correlated, while the structural break observed by Bai and Perron test coincided with major economic shocks, policy changes and the establishment of regional trade policies. The VAR model Granger causality test observed no volatility spillover from Chinese economic activities to the ASEAN-5 stock markets, except for Malaysia and the Philippines. However, the ASEAN-5 stock markets’ volatility exerts a significant influence on China’s economy, except for Singapore’s stock market volatility. This study reveals that ASEAN-5 has gradually became the preferred destination for diversifying equity portfolios for investors in China.

Equity portfolio diversification with high frequency data

Investors wishing to achieve a particular level of diversification may be misled on how many stocks to hold in a portfolio by assessing the portfolio risk at different data frequencies. High frequency intradaily data provide better estimates of volatility, which translate to more accurate assessment of portfolio risk. Using 5-min, daily and weekly data on S&P500 constituents for the period from 2003 to 2011, we find that for an average investor wishing to diversify away 85% (90%) of the risk, equally weighted portfolios of 7 (10) stocks will suffice, irrespective of the data frequency used or the time period considered. However, to assure investors of a desired level of diversification 90% of the time (in contrast to on average), using low frequency data results in an exaggerated number of stocks in a portfolio when compared with the recommendation based on 5-min data. This difference is magnified during periods when financial markets are in distress, as much as doubling during the 2007–2009 financial crisis.

International Small Cap:Defininga Promising Asset Class

The benefits of international equity portfolio diversification have been well documented. Until recently, however, most investors worldwide have concentrated exclusively on large cap names from developed countries (Ferreira and Matos [2006]; Kang and Stulz [1997]). This focus on large, often multinational companies with strong brand recognition benefited investors as they began to reduce the home-country bias within their portfolios. Unfortunately, as often happens when a market, sector, or individual company becomes widely followed, the prospective benefits to be gained–risk reduction, greater return potential, or both–have declined. Macro global factors common to developed large cap companies now explain much of their performance, while increased analyst coverage and more transparent reporting have reduced information inefficiencies (Yan [2009]). All of this has led to more highly correlated performance and lessened the magnitude of the potential benefits that investors were seeking by diversifying their portfolios away from a single country or region.

Equity Portfolio Diversification: How Many Stocks are Enough? Evidence from Five Developed Markets

In this study of five developed markets we analyse the sizes of portfolios required for achieving most diversification benefits. Using daily data, we trace the year-to-year dynamic of these sizes between 1975 and 2011. We compute several widely-accepted measures of risk and use an extreme risk measure to account for black swan events. In addition to providing portfolio size recommendations for an average investor, we estimate confidence bands around central measures of risk and offer recommendations for attaining most diversification benefits 90 percent of the time instead of on average. We find that investors concerned with extreme risk can achieve diversification benefits with a relatively small number of stocks.

Regime shifts in mean-variance efficient frontiers: Some international evidence

This article examines how the presence of regimes in means, variances and correlations of asset returns translates into explicit dynamics of the Markowitz mean-variance frontier (MVF). In particular, the article shows both theoretically and through an application to international equity portfolio diversification that substantial differences exist between bull and bear regime-specific frontiers, both in statistical and in economic terms. Using Morgan Stanley Capital International investable indices for five countries/macro-regions, it is possible to characterize the MVFs and optimal portfolio strategies in bull periods, in bear periods and in periods in which high uncertainty exists on the nature of the current regime. A recursive back-testing exercise shows that between 1998 and 2010, adopting a switching mean-variance strategy may have yielded considerable risk-adjusted pay-offs, which were the largest in correspondence to the 2007–2009 financial crisis.

Regime Shifts in Mean-Variance Efficient Frontiers: Some International Evidence

Regime switching models have been assuming a central role in financial applications because of their well-known ability to capture the presence of rich non-linear patterns in the joint distribution of asset returns. This paper examines how the presence of regimes in means, variances, and correlations of asset returns translates into explicit dynamics of the Markowitz mean-variance frontier. In particular, the paper shows both theoretically and through an application to international equity portfolio diversification that substantial differences exist between bull and bear regime-specific frontiers, both in statistical and in economic terms. Using Morgan Stanley Capital International (MSCI) investable indices for five countries/macro-regions, it is possible to characterize the mean-variance frontiers and optimal portfolio strategies in bull periods, in bear periods, and in periods where high uncertainty exists on the nature of the current regime. A recursive back-testing exercise shows that between 1998 and 2010, adopting a switching mean-variance strategy may have yielded considerable risk-adjusted payoffs, which are the largest in correspondence to the 2007-2009 financial crisis.

International equity portfolio allocations and transaction costs

In spite of the critical role of transaction cost, there are not many papers that explicitly examine its influence on international equity portfolio allocation decisions. Using bilateral cross-country equity portfolio investment data and three direct measures of transaction costs for 36 countries, we provide evidence that markets where transaction costs are lower attract greater equity portfolio investments. The results imply that future research on international equity portfolio diversification cannot afford to ignore the role of transaction costs, and policy makers, especially in emerging markets, will have to reduce transaction costs to attract higher levels of foreign equity portfolio investments.

International Risk Sharing: Through Equity Diversification or Exchange Rate Hedging?

Well-known empirical puzzles in international macroeconomics concern the large divergence of equilibrium outcomes for consumption across countries from the predictions of models with full risk sharing. It is commonly believed that these risk-sharing puzzles are related to another empirical puzzle-the home-bias in equity puzzle. However, we show in a series of dynamic models that the full risk sharing equilibrium may not require much diversification of equity portfolios when there is price stickiness of the degree typically calibrated in macroeconomic models. This conclusion holds under a range of assumptions about home bias in preferences, price setting as PCP or LCP, and with or without nominal wage stickiness as long as there is some price rigidity.

International Risk Sharing: Through Equity Diversification or Exchange Rate Hedging?

Well-known empirical puzzles in international macroeconomics concern the large divergence of equilibrium outcomes for consumption across countries from the predictions of models with full risk sharing. It is commonly believed that these risk-sharing puzzles are related to another empirical puzzle-the home-bias in equity puzzle. However, we show in a series of dynamic models that the full risk sharing equilibrium may not require much diversification of equity portfolios when there is price stickiness of the degree typically calibrated in macroeconomic models. This conclusion holds under a range of assumptions about home bias in preferences, price setting as PCP or LCP, and with or without nominal wage stickiness as long as there is some price rigidity.

Equity portfolio diversification under time-varying predictability: Evidence from Ireland, the US, and the UK

We use multivariate regime switching vector autoregressive models to characterize the time-varying linkages among short-term interest rates (monetary policy) and stock returns in the Irish, the US and UK markets. We find that two regimes, characterized as bear and bull states, are required to characterize the dynamics of returns and short-term rates. This implies that we cannot reject the hypothesis that the regimes driving the markets in the small open economy are largely synchronous with those typical of the major markets. We compute time-varying Sharpe ratios and recursive mean-variance portfolio weights and document that a regime switching framework produces out-of-sample portfolio performance that outperforms simpler models that ignore regimes. The portfolio shares derived under regime switching dynamics implies a fairly low commitment to the Irish market.

Equity Portfolio Diversification Under Time-Varying Predictability and Comovements: Evidence from Ireland, the US, and the UK

We use multivariate regime switching vector autoregressive models to characterize the time-varying linkages among short-term interest rates (monetary policy) and stock returns in the Irish, the US and UK markets. We find that two regimes, characterized as bear and bull states, are required to characterize the dynamics of returns and short-term rates. This implies that we cannot reject the hypothesis that the regimes driving the markets in the small open economy are largely synchronous with those typical of the major markets. We compute time-varying Sharpe ratios and recursive mean-variance portfolio weights and document that a regime switching framework produces out-of-sample portfolio performance that outperforms simpler models that ignore regimes. Interestingly, the portfolio shares derived under regime switching dynamics implies a fairly low commitment to the Irish market, in spite of its brilliant unconditional risk-return trade-off.

The changing benefits of global equity investing: Developed and emerging markets, 1997–2007

Are there any long standing benefits in international equity investing? Did the acceleration of global financial integration bring clearly measurable benefits to international equity investors? Is there a convergence of equity market profitability around the world? These are the main questions of this paper. All of these questions got an affirmative answer, but, as it may be immediately suspected, many durable qualifiers and caveats apply. Section 1 reviews some key propositions of modern investment theory and some recent evidence on the benefits of international asset allocation on equity markets. It is argued that the desired benefits — as predicted by theory — can be and have been captured in terms of better risk/return trade-offs due to international diversification of equity portfolios. Manifest benefits aside, however, many dampening factors come into play when considering long term capacities of realising these benefits. Mainly the changing correlation structure of global markets and the increased currency risk, which still remained very difficult to hedge, were identified as permanent factors to limit the power of international diversification in pushing out the efficient frontier of the equity set. Section 2 presents comparative evidence on global equity markets’ performance and gives an account of the wide variations in the US dollar denominated returns of major markets, developed and emerging. There is some support to the view that a certain convergence can be depicted in the profitability levels of different markets. Exchange rate movements, however, accounted for almost one third of variations in profitability on average. As of April 2007, stock market valuations did favour emerging markets (and to some extent EU-27) when compared to Japan or the US.