Portfolio Analysis Using Single Index,Multi-Index,and Constant Correlation Models: A Unified Treatment

In this study a simple common algorithm which is applicable to seven models is proposed for optimal portfolio selection disallowing short sales of risky securities. The models considered in the analysis consist of a single index model, four multi-index models, and two constant correlation models. Unlike the previous approach, the proposed algorithm does not require explicit ranking of securities. Therefore, it is particularly useful for two multi-index models with orthogonal indices which do not provide any ranking criterion. Also, because of its algorithmic efficiency as demonstrated in a simulation study on models with multiple groups, the approach here can enhance their usefulness in portfolio analysis.