Given the
number of uncertainties involved in trying to estimate a sustainable level
of retirement spending — how the markets will perform, how long you'll live, what your
actual expenses will be (although on that score, doing a retirement budget can help)-- you might also consider turning a portion
of your nest
egg into income assured to last no matter how long you live and regardless
of how the markets fare by investing in an immediate annuity or longevity annuity.