[danielmarkbruce]

The IRR is equivalent. You can't eat(spend) IRR.

The NPV is not equivalent (unless you happen to have a cost of capital = 25%... like about 10 people). The cash on cash is not equivalent. Every person on planet earth will take the 15 year compounding (again except the 10 or so..).... hence they are not equivalent. When returns are high, investors are not indifferent to time horizon. Longer is better. To make it extremely clear - would you prefer IRR of 50% for 1 minute or 10 years?

The only statement which is precise enough is "the IRR is equivalent". Anyone can be pedantic, it rarely helps.

[danuker]

You are right. Only in a zero-interest-rate environment are they "equivalent" WRT NPV. If you can safely get high returns, then you have to discount them.

[danielmarkbruce]

They are equivalent NPV wise only when the cost of capital is 25%. Cost of capital is a fuzzy concept and different folks have different numbers based on all kinds of things (despite the precise numbers put in spreadsheets). From a practical perspective they will almost never be NPV equivalent.