In this paper we adapt the empirical similarity (ES) concept for the purpose of combining volatility forecasts originating from different models. Our ES approach is suitable for situations where a decision maker refrains from evaluating success probabilities of forecasting models but prefers to...

How to quantify estimation risk is important in portfolio selection. For this purpose we derive the flexible shrinkage estimator for the optimal portfolio weights, which allows dynamic adjustments of model structure. Our estimator is based on grouping the assets in order to capture...

This paper proposes a multivariate shrinkage estimator for the optimal portfolio weights. The estimated classical Markowitz weights are shrunk to the deterministic target portfolio weights. Assuming log asset returns to be i.i.d. Gaussian, explicit solutions are derived for the optimal shrinkage...