Knowledge that Transforms

We examine time-invariant and time-varying market integration across European stock markets. Financial integration increases during the sovereign debt crisis and is mainly driven by macroeconomic variables, market capitalization, political uncertainty, and technological developments. Higher market integration is associated with decreasing diversification benefits. During crises, investors select portfolios that are not only explained by firm characteristics.

We introduce a simple and intuitive approach of modeling and forecasting correlations for use in portfolio optimization. The model is composite in nature and consists of elements based on a bivariate realized volatility model. Importantly, our framework allows for volatility spill-overs between assets which provide an edge compared to competing models when forming portfolios. We apply the model to high-frequency data for commodity markets and demonstrate significant economic gains for an investor basing portfolio decisions on our modeling framework. This gain is significant in economic terms, even after imposing realistic constraints on short selling and portfolio turnover.