Or, the replacement rate considered to be adequate can be computed in a more sophisticated way, netting out Social Security taxes, other taxes, or working expenses that will not be paid in retirement.
The current computation of replacement rate must be improved. 
mnli hypothesis: The current computation of replacement rate must be improved.  premise: Or, the replacement rate considered to be adequate can be computed in a more sophisticated way, netting out Social Security taxes, other taxes, or working expenses that will not be paid in retirement.