Disadvantages of Stratified Sampling Approach to Equity Portfolio Mgmt costs, books, index, factors, between

jbaldyga

The books don't seem to elaborate to much on the disadvantages of this approach. From what I can gather its:

>Increased trading costs over full replication approach to align portfolio with characteristics of index
>Implicitely assumes that the covariances between risk factors are uncorrelated

Any other thougths?