Studies on a general stock-bond integrated portfolio optimization model

The purpose of this paper is to extend a stock-bond integrated portfolio optimization model proposed by one of the authors in 1997 to the case where the universe covers risky (corporate) bonds in addition to stocks and risk-free (government) bonds. An integrated approach has been applied to Japanese market and was proved to generate a portfolio which usually outperforms standard asset allocation strategy. Inclusion of risky bonds is expected to lead to an even better portfolio. To properly handle risky bonds, we introduce a new scheme to quantify the risk associated risky bonds. We will demonstrate that the scheme proposed in this paper works very well, at least in the Japanese market.