Robust Markowitz mean‐variance portfolio selection under ambiguous covariance matrix

This paper studies a robust continuous‐time Markowitz portfolio selection problem where the model uncertainty affects the covariance matrix of multiple risky assets. This problem is formulated into a min–max mean‐variance problem over a set of nondominated probability measures that is solved by a McKean–Vlasov dynamic programming approach, which allows us to characterize the solution in terms of a Bellman–Isaacs equation in the Wasserstein space of probability measures. We provide explicit solutions for the optimal robust portfolio strategies and illustrate our results in the case of uncertain volatilities and ambiguous correlation between two risky assets. We then derive the robust efficient frontier in closed form, and obtain a lower bound for the Sharpe ratio of any robust efficient portfolio strategy. Finally, we compare the performance of Sharpe ratios for a robust investor and for an investor with a misspecified model.     

Assessment of blockchain applications in travel and tourism industry

Quality & Quantity - Blockchain technology (BCT) is a network-based system, which is developed to create secure, smart and transparent distributed ledgers. Recently, BCT has been gaining more...     

Determinants of migration from ASEAN‐3 into Malaysia

Migration theory advances several reasons for migration, which can be categorised into two groups: push factors and pull factors. Push factors include the economic performance of the emigrating country, whereas the pull factors include performance in the destination country. The latter include gross domestic product, job creation, the unemployment rate, education level, and wage rate. This paper examines the determinants of immigration from the Association of Southeast Asian Nations (ASEAN)‐3, namely Indonesia, Thailand, and the Philippines, into Malaysia. The analysis is based on panel data of 1990–2008 using the Autoregressive Distributed Lag approach. The results show that the main determinants of this migration flow are the real wage ratio among the ASEAN‐3 and Malaysia, the unemployment rate in the source countries, and the real exchange rate ratio between the ASEAN‐3 and Malaysia.     

Islamic tourism: an empirical examination of travel motivation and satisfaction in Malaysia

The objectives of this study are to test the relationship between tourism motivations and tourist satisfaction, and to test how ‘Religion’ moderates the relationship. The variable ‘Religion’ is represented by the availability of Islamic norms and practices relevant to tourism at the destination. The results of the partial least square indicate that tourism motivations are significantly and positively related to tourist satisfaction. The results also showed that Religion significantly moderates the relationship between pull motivation and tourist satisfaction. However, the moderating effect of Religion on the relationship between push motivation and tourist satisfaction was not supported.     

Time series analysis of the nexus among corruption,political instability and judicial inefficiency in Pakistan

The purpose of this study is two folds: firstly, to analyze the direction of causality between corruption and political instability directly and secondly, to determine the causality between corruption and political instability indirectly through judicial inefficiency in Pakistan. The causality between corruption, political instability and judicial inefficiency is tested by applying Toda–Yamamoto Granger causality test. The results show that there is a lack of direct causal relationship between corruption and political instability. However, political instability and corruption cause each other indirectly through judicial inefficiency. The study highlights the critical role of judicial inefficiency leading to an important policy implication.