If different investors have different tax rates, then the amount of tax paid on the cash inflow will vary among investors, as will the after-tax (borrowing) riskless interest rate. As a result, the present value of the future riskless after-tax cash inflow
may vary among investors if they have different tax rates and each of them calculates present value by discounting his or her after-tax riskless cash inflow using his or her after-tax riskless (borrowing) interest rate.