The **internal rate of return** is a very useful decision rule in deciding whether or not to **accept** a project or a firm but in some cases, we don’t even have an IRR. It’s **non-existent,** There is no IRR for the cash flows of a given project and in those cases, we have to use the net present value.

**a non-existent IRR**for a project but first I just want to quickly review the

**decision rule**for IRR and that is

**we’re only going to accept a project if the internal rate of return is greater than the cost of capital**and by that I mean the

**opportunity cost of capital**so if IRR is higher than the cost of capital we accept but

**this decision rule is only guaranteed to work if all of the negative cash flows of that project come before the positive cash flows.**

**break down.**

You start a construction company and you raise or you get this first project where you get

5milliondollars upfront is sort of a down payment and then you get the rest of the money for the project which is17millionat the end ofyear 5so there’s going to be afive-yearproject now for thefirst 4 yearsof the project you’re gonna be incurring expenses as you build this building or whatever it is you’re constructing so there’s going to be4milliondollars a year in expenses and yourcost of capitalwill be10%.

**five-year**project so we have

**zero**here then

**1st year, 2nd year, 3rd year,**

**year 4**and

**5.**The zero this is just the beginning of the project you’re gonna get

**5million**dollars now and then in the middle or I should say in between this initial cash flow that you get in

**year zero**and the end at

**year 5**where you get

**17 million**you’re going to have negative cash flows for

**four years**of

**4million**dollars. So you get

**5million**upfront and then

**4 years**in a row you get it for the next 4 years you get negative

**4 million**as you’re building the building and incurring expenses and at the end of

**year 5**you don’t incur any expenses you just get that final payment of

**17million**dollars so the cost of capital is

**10%**

**internal rate of return**for these cash flows, so I go and I plug it into Excel

I use the equals IRR function and however, you want to calculate it by hand you can do it we have another article about calculating IRR, and I got an error message in Excel because there is **no internal rate of return** for this project for this particular set of cash flows there is no IRR. So there’s nothing where the NPV would be **zero** there’s no rate of return. So basically we have to solve for NPV. We don’t even have an IRR to even compare against our cost of capital, so really IRR is meaningless here.

We’re just gonna discount all these cash flows and so forth so we’re gonna end up with a net present value of positive** $2,876,201.** So that means we are going to **accept** the project. So we used NPV because there is no IRR but just because we’re accepting this project and we had a positive NPV does not mean that if you have no IRR that you’re automatically gonna accept the project that it means that there’s a **positive NPV** it just as easily could have been that there was a **negative NPV.** So we could come up with a different set of cash that would end up with a negative NPV and still, no IRR so if there’s no IRR you don’t have any internal rate of return and it just doesn’t exist just forget about the internal rate of return altogether and go ahead and **calculate the NPV** and then here we’ve got a **positive NPV** so you **accept** the project. That’s your decision.