International portfolio selection and efficiency analysis

In the risk-return tradeoff, the traditional mean-variance analysis has been widely used for studies of international portfolio efficiency and diversification. Without prior knowledge about either the parametric structure of assets' return distributions or the form of investors' preference functions, the variance may no longer serve as a suitable risk proxy. This article examines international portfolio efficiency and diversification effects through mean-variance and various distribution-free (or less restrictive) risk-return measures. We show empirically that the mean-variance model is appropriate for large or well-diversified portfolios, but may provide biased results for single assets and less diversified portfolios. While stochastic dominance stands as theoretically the most appropriate method of international portfolio selection and efficiency analysis, the lack of optimal search algorithms reduces its practical usefulness. Very little gain is obtained by using the Gini-mean-difference risk measure as compared to the semivariance measure. The semivariance measure is a powerful and convenient discriminator of risky prospects, while stochastic dominance can serve as a benchmark to justify portfolio efficiency.     

Applying portfolio theory to global bank lending

Portfolio theory provides some insights into how a bank should manage its global exposures. Practical application of some of the principles of portfolio analysis is possible if comparable credit ratings are available and if the impact on each loan's rating of likely future events can be assessed. If further restrictive assumptions are made about which quality dimensions of the portfolio are more important (and how much more important), and if judgements can be quantified about what risk-return tradeoffs are acceptable, then it is possible to derive measures to guide exposure and pricing decisions. This article is related to the other papers in this special issue in that country and corporate risk assessment methodologies can provide important inputs into the portfolio analysis. This paper, however, attempts to go beyond the evaluation of risk at the level of individual companies, countries, or other loan customers, and to focus instead on the problem of managing the riskiness of the overall bank loan portfolio.     

Multi-factor Risk-return Relationships

This paper derives three multi-factor risk-return relationships each of which employs macro-economic variables in presenting the underlying factors that influence security returns. The first relationship holds if the underlying portfolio lies on the expected return-standard deviation efficient frontier, the second is valid when the underlying portfolio lies inside the efficient frontier and the third characterises security markets in which no arbitrage opportunities are present. An attempt is also made to appraise critically previous multi-factor risk-return relationships which rely on an expected return-standard deviation approach.     

Does reinforcement learning outperform deep learning and traditional portfolio optimization models in frontier and developed financial markets?

Advancements in machine learning have opened up a wide range of new possibilities for using advanced computer algorithms, such as reinforcement learning in portfolio risk management. However, very little evidence has been provided on the superior performance of reinforcement learning models over traditional optimization models following the mean-variance framework in different financial market settings. This study uses two experiments with data from the Vietnamese and U.S. securities markets to justify whether advanced machine learning models could outperform traditional portfolios' cumulative returns while optimizing the Sharpe ratio. The results suggest that reinforcement learning consistently outperforms the established methods and benchmarks in both experiments, even when using a very similar degree of diversification in portfolio construction and the same input data. This study confirms the ability of reinforcement learning to provide dynamic responses to market conditions and redefine the risk-return standard in the financial system.     

Sources of Systematic Risk in Futures and Spot Markets: A Study of Market Integration

This article explains the implications of asset market integration for the decision making process of market participants and tests the integration between futures and spot markets. Integration is investigated with respect to the hypothesis that the sources of systematic risk in futures and spot markets command identical risk premia. While the futures and the spot markets for currencies and equities are integrated, we present new evidence that the futures and commodity spot markets are segmented. Such results are of primary importance to investors who use asset pricing models to adjust the risk-return trade-off of their portfolio and evaluate portfolio performance.     

A SIMPLIFIED APPROACH TO SHORT-TERM INTERNATIONAL DIVERSIFICATION

Using Eurocurrency deposit interest rates, currency exchange rates, and inflation rates in a mean-variance portfolio analysis, the authors develop portfolios of interest-bearing deposits in London banks denominated in various currencies. These easily constructed multicurrency portfolios are shown to provide better risk-return positions than comparable single currency holdings.     

Portfolio Rebalancing and the Turn-of-the-Year Effect

This paper finds that, for the 1935–1986 period, the market's risk-return relation does not have a January seasonal. The findings differ from those of other studies due to the use of value-weighted, rather than equally weighted, portfolios. Inferences are sensitive to the weighting procedure because of the small-firm return patterns in January. In particular, even in those Januaries for which the market return is negative, small-firm returns are positive, and they are more positive the higher is beta. This is consistent with the portfolio rebalancing explanation of the turn-of-the-year effect.     

Dynamic Volatility Trading Strategies in the Currency Option Market

The conditional volatility of foreign exchange rates can be predicted using GARCH models or implied volatility extracted from currency options. This paper investigates whether these predictions are economically meaningful in trading strategies that are designed only to trade volatility risk. First, this article provides new evidence on the issue of information content of implied volatility and GARCH volatility in forecasting future variance. In an artificial world without transaction costs both delta-neutral and straddle trading stratgies lead to significant positive profits, regardless of which volatility prediction method is used. Specifically, the agent using the Implied Stochastic Volatility Regression method (ISVR) earns larger profits than the agent using the GARCH method. Second, it suggests that the currency options market is informationally efficient. After accounting for transaction costs, which are assumed to equal one percent of option prices, observed profits are not significantly differentfrom zero in most trading strategies. Finally, these strategies offered returns have higher Sharpe ratio and lower correlation with several major asset classes. Consequently, hedge funds and institutional investors who are seeking alternative “marketneutral” investment methods can use volatility trading to improvethe risk-return profile of their portfolio through diversification. This revised version was published online in November 2006 with corrections to the Cover Date.     

Portfolio frontiers with restrictions to tracking error volatility and value at risk

Asset managers are often given the task of restricting their activity by keeping both the value at risk (VaR) and the tracking error volatility (TEV) under control. However, these constraints may be impossible to satisfy simultaneously because VaR is independent of the benchmark portfolio. The management of these restrictions is likely to affect portfolio performance and produces a wide variety of scenarios in the risk-return space. The aim of this paper is to analyse various interactions between portfolio frontiers when risk managers impose joint restrictions upon TEV and VaR. Specifically, we provide analytical solutions for all the intersections and we propose simple numerical methods when such solutions are not available. Finally, we introduce a new portfolio frontier.     

The shrouded business of style drift in active mutual funds

This study investigates the motivation and performance consequence of intentional style drift in an exclusively in-house fund management industry in China. With style drift, fund investors are exposed to investment portfolio outside their risk-return preference but are generally unaware that their risk and return expectations are disrupted, and the functioning of the fund market undermined. Our study provides evidence for the first time about the incentive that motivates style drift behavior. We find that style drift increases a fund's subsequent net inflows, thus affirming the maximization of AUM-linked compensation as the motivation for fund manager's style drift behavior. We also find that larger funds have greater incentive to drift. We demonstrate that style drift behavior interferes with the picking of quality stocks to deliver fund performance for fund investors. Style drift as an unobserved risk behavior harms fund investor interest and undermines market integrity.     

CAPITAL BUDGETING DECISIONS WHEN CASH FLOWS AND PROJECT LIVES ARE STOCHASTIC AND DEPENDENT

The purpose of this study is twofold: (1) to develop an operational economic state and simulation capital budgeting procedure for allowing cash flows and project lives to be dependent and (2) to provide empirical evidence of the impact of stochastic project lives on mean-variance and mean-semivariance capital budgeting decisions. The required number of input estimates for the proposed model is small. For individual projects, incorrectly assuming deterministic project lives when project lives are stochastic often results in large overestimates of expected net present values and large underestimates of the variance of the net present value. Similar results occur for the mean-variance and mean-semivariance portfolio models. The primary managerial implication of this study is that the inclusion of stochastic project lives in capital budgeting decisions is critical to obtain appropriate risk-return estimates.     

Dynamic correlations and volatility effects in the Balkan equity markets

This paper investigates the presence of time-varying comovements, volatility implications and dynamic correlations in major Balkan and leading mature equity markets, in order to provide quantified responses to international asset allocation decisions. Since asset returns and correlation dynamics are critical inputs in asset pricing, portfolio management and risk hedging, emphasis is placed on the respective (constant and dynamic) equity market correlations produced by alternative multivariate GARCH forms, the Constant Conditional Correlation and the Asymmetric Dynamic Conditional Correlation models. The Balkan stock markets are seen to exhibit time-varying correlations as a peer group, although correlations with the mature markets remain relatively modest. In conjunction with sensitivity analysis on the asymmetric variance–covariance matrix, active portfolio diversification to the Balkan equity markets indicates to potentially improve investors’ risk-return trade-off.     

On the Inverse of the Covariance Matrix in Portfolio Analysis

The goal of this paper is the derivation and application of a direct characterization of the inverse of the covariance matrix central to portfolio analysis. Such a characterization, in terms of a few primitive constructs, provides the basis for new and illuminating expressions for key concepts as the optimal holding of a given risky asset and the slope of the risk-return efficiency frontier faced by the individual investor. The building blocks of the inverse turn out to be the regression coefficients and residual variance obtained by regressing the asset's excess return on the set of excess returns for all other risky assets.     

Discussion of “CEO discretionary power,unconstrained stock ownership,and stock trading: Theory and evidence”

Hong (2023) provides both an analytical model and empirical archival evidence to explain why CEOs hold vested own-firm shares when doing so comes at the cost of reduced CEO portfolio wealth diversification. I discuss Hong (2023) in terms of the intuition provided by its analytical model and the inferences one can draw from its empirical results. Moreover, I briefly discuss (the lack of) multi-methods research in accounting and consider how accounting scholars can add insight to the cross-disciplinary literature on executive power and contracting.     

Role of corporate governance in moderating the risk-return paradox: Cross country evidence

This paper investigates the possible nexus between the 'risk-return paradox' and corporate-governance of firms in a cross-country cross-cultural setup. We use corporate governance as well as accounting risk and return data for a large dataset of 45,322 firm-years from 27 countries and show that the firm-level risk-return association may be a non-linear one, contingent on the firm performance. Firms which are below the industry median in terms of operating performance, exhibit an inverse relation in line with Bowman's (1980) ‘paradox' while those above-median exhibit a positive risk-return association. Further, we establish empirically that such risk-return association could be due to the rent-seeking actions of managers and that strong corporate-governance in a firm substantially moderates and reverses these effects. Our results are robust and hold strong through a number of robustness tests.     

Macroeconomic influences on optimal asset allocation

We develop a tactical asset allocation strategy that incorporates the effects of macroeconomic variables. The joint distribution of financial asset returns and the macroeconomic variables is modelled using a VAR with a multivariate GARCH (M-GARCH) error structure. As a result, the portfolio frontier is time varying and subject to contagion from the macroeconomic variable. Optimal asset allocation requires that this be taken into account. We illustrate how to do this using three risky UK assets and inflation as a macroeconomic factor. Taking account of inflation generates portfolio frontiers that lie closer to the origin and offers investors superior risk-return combinations.     

Unfolded risk-return trade-offs and links to Macroeconomic Dynamics

A general partial risk-return relation is derived based on return decomposition to allowing for the effect of time-varying skewness and kurtosis on the risk-return trade-off. Empirically estimated for 12 international financial markets, the proposed risk-return trade-off is significantly positive even after controlling for time-varying higher moments. Moreover, the stochastic dominance test reveals that modeling time-varying skewness significantly lowers the level of the risk-return trade-off. More importantly, the empirical evidence shows that the risk-return trade-off is countercyclical in the U.S. markets, consistent with the theoretical habit-formation model of Campbell and Cochrane (1999), whereas the risk-return trade-offs in European and emerging markets appear to be procyclical over a 12-month horizon, but countercyclical for a shorter horizon of 3 months. Finally, common macroeconomic variables can significantly explain risk-return trade-off dynamics.     

FOREIGN-CURRENCY ACCOUNTING METHODS: REPORTING THE EXCHANGE RATE RISK EXPOSURE OF EQUITY

This study tests whether Australian firms' unregulated foreign-currency accounting policies indicated the extent to which equity claims against the firm were exposed to exchange rate risk. Evidence supports the hypothesis that the methods of accounting for foreign-currency gains and losses on long-term monetary-items were associated with the exposure. Methods of disposing of the gains and losses arising from translation of the accounts of overseas subsidiaries were also associated with the exposure, but not in the manner predicted. The results indicate that foreign-currency accounting policies were established in an interactive (portfolio) decision-making process, and that managers reported equity claim exposures relative to the returns to equity claims against other firms. Overall, the study provides evidence that at least some unregulated choices of foreign-currency accounting methods were made to minimise the agency costs associated with contracts between shareholders and management.     

International diversification and Microfinance

International commercial banks, institutional investors, and private investors have become increasingly interested in financing microfinance institutions (MFIs). This paper investigates whether adding microfinance funds to a portfolio of risky international assets yields diversification gains. By using mean-variance spanning tests with short-sale constraints, we find that investing in microfinance may be attractive for investors seeking a better risk-return profile. Specifically, the analysis suggests that investing in MFIs from Latin America, or microfinance and rural banks yields more efficient portfolios. In contrast, adding MFIs from Africa or microfinance NGOs to a portfolio of international assets is not beneficial for a mean-variance investor.     

Why do banks choose to finance with equity?

A majority of U.S. banks between 1973 and 2012 held equity capital significantly beyond the required minimum. We study the risk-return tradeoff in connection with a bank’s capital structure, and identify several new significant market factors that drive the level of equity capital in banks. During normal growth periods, bank leverage is negatively related to a level of competition and loan portfolio diversification, while high bank leverage is associated with low past liquidity. During recessions and expansions, the roles of those factors change following distortions in risk-return tradeoff. In distress, when banks approach regulatory capital requirements, market determinants of book leverage lose their significance; however, leverage does not decrease until a bank is within 1% of the minimal capital threshold.