Faculté des sciences

How to quantify the influence of correlations on investment diversification

Medo, Matúš ; Yeung, Chi Ho ; Zhang, Yi-Cheng

In: International Review of Financial Analysis, 2009, vol. 18, no. 1-2, p. 34-39

When assets are correlated, benefits of investment diversification are reduced. To measure the influence of correlations on investment performance, a new quantity—the effective portfolio size—is proposed and investigated in both artificial and real situations. We show that in most cases, the effective portfolio size is much smaller than the actual number of assets in the portfolio and that it... Plus

Ajouter à la liste personnelle
    Summary
    When assets are correlated, benefits of investment diversification are reduced. To measure the influence of correlations on investment performance, a new quantity—the effective portfolio size—is proposed and investigated in both artificial and real situations. We show that in most cases, the effective portfolio size is much smaller than the actual number of assets in the portfolio and that it lowers even further during financial crises.