How is the present value of periodic payments calculated in the calculation of attorney fees?

In addition, the Present Value approach invites the attorney to "beef up" the value of the periodic payments by including certain noncash benefits to the client such as the taxes the client will save over a lifetime by receiving periodic payments instead of investing a lump sum payment and the management costs the client saves by not having to hire someone to manage a lump-sum investment. (Computation of Attorney Fees, supra, at pp. 589-590; and see Schneider v. Kaiser Foundation Hospitals (1989) 215 Cal.App.3d 1311, 1319 & fn. 6, 264 Cal.Rptr. 227 [rejecting inclusion of such noncash benefits in calculation of present value of periodic payments].)