NPV

The NPV function computes the net present value of a series of cash flow values.

Return Value

DECIMAL

Syntax

NPV(cashflows, discount-rate, [time-dimension])

Arguments

cashflows: A numeric expression that is dimensioned by time-dimension and specifies the series of cash flow values.
discount-rate: A numeric expression that specifies the interest rate for each period to be used to discount the cash flow values. It can either be a single value or an array of values with one or more non-time dimensions. You should express the discount rate as a decimal quantity; for example, 8.25 percent as .0825.
time-dimension: A name that specifies the time dimension. When cashflows has a dimension of type DAY, WEEK, MONTH, QUARTER, or YEAR, NPV will automatically use that dimension, and you can omit the time-dimension argument.

Notes

The Dimensions of the Result

The result returned by the NPV function is dimensioned by all the dimensions of cashflows except its time dimension. When cashflows is dimensioned only by the time dimension, NPV returns a single value.

Cash Flow Occurrences

All cash flows are assumed to occur at the beginning of the time period with which they are associated.

Cash Flows Discounted

The cash flows are discounted back to the beginning of the earliest time period that appears in the current status of the time dimension.

Ignored Cash Flows

NPV ignores cash flows that corresponds to out-of-status dimension positions.

NASKIP Option Settings

NPV is affected by the NASKIP option. When NASKIP is set to YES (the default), NPV ignores NA cash flows and computes net present value using the cash flows that are available. When NASKIP is set to NO, NPV returns NA when any cash flow has a value of NA. When all the cash flows are NA, NPV returns NA for either setting of NASKIP.

NA Discount Rate

When the discount rate used to compute a result value is equal to NA, then that result value is NA.

Negative Discount Rates

NPV accepts any positive discount rate, and it also accepts a negative discount rate when the rate is greater than minus one (that is, rate > -1). When you supply a negative rate, you must precede it with a comma.

Cash Flow Timing

Different assumptions about the intra-period timing of the cash flows, or the base time point for the present value calculations, can be accommodated by multiplying the result of the NPV function by the following quantity: one plus the discount rate, raised to an appropriate positive or negative power.

Examples

Example 18-38 Computing the Net Present Value

The following statements create a dimension called project, add values to it, and create a variable called cflow, which is dimensioned by year and project.

DEFINE project DIMENSION TEXT
MAINTAIN project ADD 'a' 'b' 'c' 'd' 'e'
DEFINE cflow VARIABLE DECIMAL <project year>

When you assign the following values to CFLOW,

------------------------CFLOW----------------------
             -----------------------PROJECT---------------------
YEAR             a          b          c          d          e
------------ ---------- ---------- ---------- ---------- -------
Yr95           -200.00    -200.00    -300.00    -100.00  -200.00
Yr96            100.00     150.00     200.00      25.00    25.00
Yr97            100.00     400.00     200.00     100.00   200.00

then the following statement

REPORT NPV(cflow, .08, year)

uses a discount rate of 8 percent to create the following report of the net present value of the cflow data.

NPV(CFLOW,
PROJECT        .08, YEAR)
-------------- ----------
a                  -21.67
b                  281.82
c                   56.65
d                    8.88
e                   -5.38