San Diego County Employees' Retirement Association will conduct an asset-liability study, said Dan V. McAllister, chairman. David Deutsch, CIO of the $5.1 billion system, will conduct the review. "His mission is to really do a thorough top-to-bottom look at the portfolio," said Mr. McAllister, who is also county treasurer-tax collector. "We're moving in the coming year to look very closely at cost." Mr. Deutsch will consider adding indexed investments to the plan for the first time, Mr. McAllister said.