Portfolio selection under higher moments using fuzzy multi-objective linear programming

Since asset returns have been recognized as not normally distributed, the avenue of research regarding portfolio higher moments soon emerged. To account for uncertainty and vagueness of portfolio returns as well as of higher moment risks, we proposed a new portfolio selection model employing fuzzy sets in this paper. A fuzzy multi-objective linear programming (MOLP) for portfolio optimization is formulated using marginal impacts of assets on portfolio higher moments, which are modelled by trapezoidal fuzzy numbers. Through a consistent centroid-based ranking of fuzzy numbers, the fuzzy MOLP is transformed into an MOLP that is then solved by the maximin method. By taking portfolio higher moments into account, the approach enables investors to optimize not only the normal risk (variance) but also the asymmetric risk (skewness) and the risk of fat-tails (kurtosis). An illustrative example demonstrates the efficiency of the proposed methodology comparing to previous portfolio optimization models.

Selection of the right risk measures for portfolio allocation

 An optimisation framework is proposed to enable investors to select the right risk measures in portfolio selection. Verification is deployed by performing experiments in developed markets (e.g., the US stock market), emerging markets (e.g., the South Korean stock market) and global investments. A preselection procedure dealing with large datasets is also introduced to eliminate stocks that have low diversification potential before running the portfolio optimisation model. Portfolios are evaluated by four performance indices, i.e., the Sortino ratio, the Sharpe ratio, the Stutzer performance index, and the Omega measure. Experimental results demonstrate that high performance and also well-diversified portfolios are obtained if modified value-at-risk, variance, or semi-variance is concerned whereas emphasising only skewness, kurtosis or higher moments in general produces low performance and poorly diversified portfolios. In addition, the preselection applied to large datasets results in portfolios that have not only high performance but also high diversification degree.

Three essays on the intraday dynamics of the foreign exchange market

Containing three essays on the intraday dynamics of the foreign exchange market, the dissertation highlights the role of higher-moments in improving the forecasting ability of exchange rates models while contributing to the literature through the identification of new calendar anomalies in the currency market which has implications for regulators and investors.

What counts as higher education? Pursuing intellectually compelling ideas

A few months ago I was sitting in a graduation ceremony considering the nature of universities; what it means to do academic work and how this constitutes some higher form of education. Unlike some of my more astute colleagues who had remembered to bring their current reading (copies of Giroux or Gelemter nestled within their graduation programs) to while away the time between applauds for graduates and speeches, I was confined to my own thoughts on matters of importance for universities and their constituents. The ceremony provided critical moments for reflection--for me, centred around the politics of meaningmincluding: the presentation to a colleague of the Vice-Chancellor's award for teaching excellence; the conferring of an honorary doctorate on the guest speaker, Fiji's Prime Minister Major-General Rabuka, for his involvement in restructuring Fiji's system of governance; and the celebration of his visit by the Vice-Chancellor, himself a would-be reformer of systems as a member of the West Review of Australian higher education.

Determinants of stock returns: Factors or systematic co-moments? Crisis versus non-crisis periods

In this paper we evaluate the intertemporal pricing performance of stock return determinants over the periods surrounding, and outside of, financial crises. The analysis focuses on the variables of size, book-to-market ratio, momentum, liquidity, and higher-order systematic co-moments. The evidence reveals that over non-crisis periods the market beta plays an important role in determining the cross-section of stock returns. Size, value, momentum, and liquidity also exhibit associations with the cross-section of stock returns. However, over crisis periods most of the variables we examined lose their explanatory power, suggesting that their usefulness is limited for investment purposes when financial markets experience crises. There is some evidence of coskewness pricing surrounding market crashes. Practitioners may consider coskewness over crisis periods.