Factor decomposition and diversification in European corporate bond markets

In this paper we present an analysis of diversification strategies on portfolios of European corporate bonds. From the perspective of a US-based investor we study whether mean–variance diversification strategies change as a result of the introduction of the European Economic and Monetary Union (EMU). Using a comprehensive and unique data set of European corporate bonds we show that country factors are more important than industry factors to describe the cross-section of European corporate bonds. In particular we find that in the Post-EMU period country factors remain important.     

Keeping up with the Joneses and optimal diversification

Peer-effects have been shown to affect behavior, and can generally lead to investments choices that are mean–variance inefficient. This paper analyzes optimal diversification with peer-effects. We show that if individuals have keeping-up with the Joneses preferences and they take their peer-group reference as the market portfolio, Markowitz’s mean–variance efficiency analysis and the CAPM equilibrium are intact. This holds for any keeping-up preferences, as well as heterogeneous combinations of such preferences. These results also extend to the Merton–Levy segmented-market model.     

Portfolio selection, diversification and fund-of-funds: a note

The present paper examines the performance and diversification properties of active Australian equity fund‐of‐funds (FoF). Simulation analysis is employed to examine portfolio performance as a function of the number of funds in the portfolio. The present paper finds that as the number of funds in an FoF portfolio increases, performance improves in a mean–variance setting; however, measures of skewness and kurtosis behave less favourably given an investor's preferences for the higher moments of the return distribution. The majority of diversification benefits are realized when a portfolio of approximately 6 active equity funds are included in the FoF portfolio.     

<Emphasis Type="Italic">K</Emphasis>-fold cross validation performance comparisons of six naive portfolio selection rules: how naive can you be and still have successful out-of-sample portfolio performance?

Recent research reports that optimal portfolio selection models often perform worse than equal-weight naive diversification in out-of-sample testing. This paper extends this line of inquiry by comparing the out-of-sample performance of the equal-weight naive strategy to the out-of-sample performance of five alternative naive strategies, each of which derives from a simple heuristic that does not require any optimization. Out-of-sample portfolio performance is assessed by mean, standard deviation, skewness, and Sharpe ratio; k-fold cross validation is used as the out-of-sample testing mechanism. The results indicate that the proposed naive heuristic rules exhibit strong out-of-sample performance, in most cases superior to the equal-weight naive strategy. These findings are consequential for at least two reasons: first, if these simple heuristic-based rules outperform the equal-weight naive strategy, then by transitivity they can outperform the mean–variance- and shortfall-optimal portfolio rules that have been shown in the literature to be inferior to the equal-weight naive rule, which further emphasizes the out-of-sample fragility of “optimal” methods; and second, among naive diversification strategies, some appear more robust in out-of-sample testing than others, hence the proposed methods may be useful when forming mixed portfolio selection models wherein a naive strategy is combined with an optimal strategy to improve performance.     

Cross‐region and cross‐sector asset allocation with regimes

Cross‐region and cross‐sector asset allocation decisions are one of the most fundamental issues in international equity portfolio management. Equity returns exhibit higher volatilities and correlations, and lower expected returns, in bear markets compared to bull markets. However, static mean–variance analysis fails to capture this salient feature of equity returns. We accommodate the nonlinearity of returns using a regime switching model across both regions and sectors. The regime‐dependent asset allocation potentially adds value to the traditional static mean–variance allocation. In addition, optimal allocation across sectors provide greater benefits compared to international diversification, which is characterized by higher returns, lower risks, lower correlations with the world market and a higher Sharpe ratio.     

Global commodities and African stocks: A ‘market of one?’

Owing to frequent fluctuations in global markets, diversifying across emerging markets is increasingly becoming a necessity. Despite this, a cloud of uncertainty surrounds the relative capacities of emerging markets to provide the required shields for international investors, especially during extreme market conditions. In this paper, we explore the relative potentials of African equities to provide opportunities for hedging and diversification for global commodity investors by using data of daily periodicity on close-to-close basis from January 3, 2003 to December 29, 2014. The findings indicate the presence of non-linear relationships between some African stocks and returns on global commodities. Thus, global commodity market investors react differently towards investment potentials in African stocks during tranquil and crisis periods. Additionally, from the mean–variance stand-point, we observe that including African equities in a diversified portfolio has the effect of lowering risk whiles simultaneously increasing expected returns. However, any such investment strategies may have to be informed by volatility persistence, as well as past and present market conditions.     

Are Smart Beta strategies suitable for hedge fund portfolios?

In the equity context different Smart Beta strategies (such as the equally weighted, global minimum variance, equal risk contribution and maximum diversified ratio) have been proposed as alternatives to the cap-weighted index. These new approaches have attracted the attention of equity managers as different empirical analyses demonstrate the superiority of these strategies with respect to cap-weighted and to strategies that consider only mean and variance. In this paper we focus our attention to hedge fund index portfolios and analyze if the results reported in the equity framework are still valid. We consider hedge fund index and equity portfolios, the approaches used for portfolio selection are the four ‘Smart Beta’ strategies, mean–variance and mean–variance–skewness. In the two latter approaches the Taylor approximation of a CARA expected utility function and the Polynomial Goal Programing (PGP) have been used. The obtained portfolios are analyzed in the in-sample as well as in the out-of-sample perspectives.     

The 2015 Maastricht-NUS-MIT International Real Estate Finance &; Economics Symposium: Editors’ Introduction to the Special Issue

We use an empirical model of commercial mortgage spreads to examine how tenant diversification impacts credit spreads for mortgages on retail properties. We find that mortgages on properties with a highly diversified tenant base have spreads that are up to 7.1 basis points higher than spreads on mortgages for single-tenant properties, but that mortgages on properties with moderate levels of tenant diversification have spreads that are up to 5.2 basis points lower than mortgages on single-tenant properties. The spread discount for mortgages on properties with moderate levels of tenant diversification disappears when the lease of the property’s largest tenant expires before the loan matures. Despite the spread discount that is given to properties with moderate levels of tenant diversification, we find that the likelihood with which a mortgage goes into default increases as tenant diversification increases.     

Price and volatility spillovers between exchange rates and stock indexes for the pre- and post-euro period

In this paper we explore the nature of the mean, volatility and causality transmission mechanism between stock and foreign exchange markets for the United States and some major European markets for the periods pre- and post-euro. The asymmetric volatility transmission is described by an extended Multivariate Exponential Generalized Autoregressive Conditionally Heteroskedastic (EGARCH) model. The results support the asymmetric and long-range persistence volatility spillover effect and show strong evidence of causality in the mean and variance between foreign exchange rate and stock price for both pre- and post-euro periods. However, the stock price has a more significant effect on foreign exchange rate for the two subsamples. These results are robust to the cross-correlation function test suggested by Cheung and Ng. The implication is particularly important for international portfolio managers when devising hedging and diversification strategies for their portfolios.     

Optimal Diversification: Reconciling Theory and Evidence

In this paper we show that the main empirical findings about firm diversification and performance are consistent with the maximization of shareholder value. In our model, diversification allows a firm to explore better productive opportunities while taking advantage of synergies. By explicitly linking the diversification strategies of the firm to differences in size and productivity, our model provides a natural laboratory to investigate several aspects of the relationship between diversification and performance. Specifically, we show that our model can rationalize the evidence on the diversification discount ( Lang and Stulz (1994) ) and the documented relation between diversification and productivity ( Schoar (2002) ).     

Dynamic asset–liability management in a Markov market with stochastic cash flows

This paper provides a general model to investigate an asset–liability management (ALM) problem in a Markov regime-switching market in a multi-period mean–variance (M–V) framework. Emphasis is placed on the stochastic cash flows in both wealth and liability dynamic processes, and the optimal investment and liquidity management strategies in achieving the M–V bi-objective of terminal surplus are evaluated. In this model, not only the asset returns and liability returns, but also the cash flows depend on the stochastic market states, which are assumed to follow a discrete-time Markov chain. Adopting the dynamic programming approach, the matrix theory and the Lagrange dual principle, we obtain closed-form expressions for the efficient investment strategy. Our proposed model is examined through empirical studies of a defined contribution pension fund. In-sample results show that, given the same risk level, an ALM investor (a) starting in a bear market can expect a higher return compared to beginning in a bull market and (b) has a lower expected return when there are major cash flow problems. The effects of the investment horizon and state-switching probability on the efficient frontier are also discussed. Out-of-sample analyses show the dynamic optimal liquidity management process. An ALM investor using our model can achieve his or her surplus objective in advance and with a minimum variance close to zero.     

Is gold good for portfolio diversification? A stochastic dominance analysis of the Paris stock exchange

This paper aims to assess the role of gold quoted in Paris in the diversification of French portfolios from 1949 to 2012 using the stochastic dominance (SD) approach. The principal advantage of this method is that there is no restriction on the distribution of the returns. Our results show that stock portfolios including gold stochastically dominate those without gold at the second and third orders. This implies that risk-averse investors would be better off by including gold in their stock portfolios to maximize their expected utilities. The study on sub-periods shows that this result holds especially in unstable or crisis times. However, these results do not hold for bond or risk-free portfolios, for which the portfolios without gold dominate those with gold. To check the robustness of our results, our SD analysis of a mixed portfolio (50% stocks, 30% bonds and 20% the risk-free asset) provides results similar to those for portfolios with stocks only, except from 1971 to 1983. Portfolios including gold quoted in London show results similar to those from Paris. The results of mean–variance performance measures confirm the findings of previous studies that gold is good for the diversification of stock portfolios but not for bond portfolios.     

Dynamic portfolio choice without cash

We consider the dynamic mean–variance portfolio choice without cash under a game theoretic framework. The mean–variance criterion is investigated in the situation where an investor allocates the wealth among risky assets while keeping no cash in a bank account. The problem is solved explicitly up to solutions of ordinary differential equations by applying the extended Hamilton–Jacobi–Bellman equation system. Given a constant risk aversion coefficient, the optimal allocation without a risk-free asset depends linearly on the current wealth, while that with a risk-free asset turns out to be independent of the current wealth. We also study the minimum-variance criterion, which can be viewed as an extension of the mean–variance model when the risk aversion coefficient tends to infinity. Calibration exercises demonstrate that for large investments, the mean–variance model without cash yields the highest certainty equivalent return for both short-term and long-term investments. Furthermore, the mean–variance portfolio choices with and without cash yield almost the same Sharpe ratio for an investment with large initial wealth.     

The effect of corporate diversification on credit risk: new evidence from European credit default swap spreads

This article investigates the impact of corporate diversification on credit risk. To our best knowledge, this is the first paper to use credit default swap (CDS) spreads instead of bond yield or revalued book values to test the risk‐reduction hypothesis. The analysis relies upon a sample of STOXX^® EUROPE 600 index members and covers the years 2010–2014. After controlling for various CDS‐ and firm‐specific variables, we find that diversification strategies do not significantly lower CDS premiums. Multilevel mediation analysis further shows that information asymmetries overcompensate the risk‐reducing effects resulting from corporate diversification.     

On the income diversification and bank market power nexus in the MENA countries: Evidence from a GMM panel-VAR approach

This paper investigates the dynamic causal relationship between revenue diversification and bank market power using a broad sample of commercial banks from 17 Middle Eastern and North African (MENA) countries over the period 1993–2014. To do so, we employ the panel vector autoregression (PVAR) approach in a generalized method of moments (GMM) framework. Moreover, we use the impulse response functions (IRFs) tool to better understand the reaction of bank market power aftershocks on revenue diversification and vice-versa. Finally, we supplement our analysis by the forecast error variance decompositions (FEVds) of our variables. Overall, the results show that the level of bank market power declines in response to positive revenue diversification shocks. Conversely, banks with a higher level of market power get more involved in non-traditional activities.     

Terrorist attacks and oil prices: Hypothesis and empirical evidence

Using a unique dataset that merges terrorism activity with oil prices, this paper develops and tests the hypothesis that terrorist attacks predict oil prices. We develop three insights. First, we show that terrorist attacks have a positive effect on oil prices, but it is attacks originating from oil producer countries that most influence oil prices. Second, we devise trading strategies based on terrorist attacks and show that attacks, by signaling buying and selling in the market, beat a buy-and-hold strategy. We also show that a mean–variance investor who utilizes our terrorism-based forecasting model makes economically meaningful profits. Our analysis also shows that the effect of terrorism on oil prices operates via both the oil production and oil investment channels.     

An Empirical Investigation of Eastern European Bond Markets

We examine the value of Eastern European emerging bond markets to global fixed income managers. In an environment where bonds from traditional developed markets are offering modest yields, emerging market bonds with attractive yields are becoming more popular with institutional managers. Furthermore, the returns on these bonds exhibit low correlations with traditional fixed income investments and thus offer opportunities for portfolio diversification. We develop a multifactor forecasting model and estimate its parameters using a dynamic Kalman filter procedure. The forecasts are then used to construct optimal mean–variance portfolios with and without emerging market bonds. We find that the portfolios that include emerging market bonds have significantly higher Sharpe ratios.     

The empirical relationship between risk and return: evidence from the UK stock market

Previous studies reach no consensus on the relationship between risk and return using data from one market. We argue that the world market factor should not be ignored in assessing the risk-return relationship in a partially integrated market. Applying a bivariate generalized autoregressive conditional heteroscedasticity in mean (GARCH-M) model to the weekly stock index returns from the UK and the world market, we document a significant positive relationship between stock returns and the variance of returns in the UK stock market after controlling for the covariance of the UK and the world market return. In contrast, conventional univariate GARCH-M models typically fail to detect this relationship. Nonnested hypothesis tests supplemented with other commonly used model selection criteria unambiguously demonstrate that our bivariate GARCH-M model is more likely to be the true model for UK stock market returns than univariate GARCH-M models. Our results have implications for empirical assessments of the risk-return relationship, expected return estimation, and international diversification.     

The economic value of range-based covariance between stock and bond returns with dynamic copulas

The covariance between stock and bond returns plays important roles in the setting up of asset allocation strategies and portfolio diversification. In the present study, we propose a multivariate range-based volatility model incorporating dynamic copulas into a range-based volatility model to describe the volatility and dependence structures of stock and bond returns. We then go on to assess the economic value of the covariance forecasts based on our proposed model under a mean-variance framework. The out-of-sample forecasting performance reveals that investors would be willing to pay between 39 and 2081 basis points per year to switch from a dynamic trading strategy under the return-based volatility model to a dynamic trading strategy under the range-based volatility model, with more risk-averse investors being willing to pay even higher switching fees. Furthermore, additional economic gains of between 33 and 1471 annualized basis points are achieved when taking the leverage effect into consideration.     

On the stability of portfolio selection models

One of the main issues in portfolio selection models consists in assessing the effect of the estimation errors of the parameters required by the models on the quality of the selected portfolios. Several studies have been devoted to this topic for the minimum variance and for several other minimum risk models. However, no sensitivity analysis seems to have been reported for the recent popular Risk Parity diversification approach, nor for other portfolio selection models requiring maximum gain–risk ratios.Based on artificial and real-world data, we provide here empirical evidence showing that the Risk Parity model is always the most stable one in all the cases analyzed with respect to the portfolio composition. Furthermore, the minimum risk models are typically more stable than the maximum gain–risk models, with the minimum variance model often being the preferable one. The Risk Parity model seems to be the most stable one also with respect to profitability when measured by the Sharpe ratio. However, the maximum gain–risk models, although quite sensitive to the input data, generally appear to attain better profitability results.