Undocumented improvements to XIRR in EXCEL 2010
Apr
26
Written by:
Charles Flock
4/26/2010 5:22 PM
XIRR in EXCEL 2010 is greatly improved over 2007, but you won’t find it mentioned in the literature.
On April 15, 2010, Microsoft announced that Office 2010 had been released to manufacturing, with those Volume Licensing customers who have Software Assurance being able to download the software from April 27. Availability in retail stores in the US starts June.
I downloaded the beta today to start comparing it to the XLeratorDB functions. I also downloaded a document called Function Improvements in Microsoft Excel 2010, dated October 2009.
Of course, the first function that I looked at was the XIRR function, a function where we have documented many shortcomings. And it seems there is some good news; EXCEL 2010 is greatly improved. All of the problems that I reported with EXCEL 2007 have been resolved; the function no longer erroneously returns zero, no longer returns unreliable results and no longer produces a different value based on sort order.
But here’s the bad news: There is no mention of the improvements/changes to the XIRR function in the supporting documentation. So it seems that it is up to me to tell you that the XIRR function in previous versions of EXCEL and EXCEL 2010 may be different … but in a good way. It would have been interesting to hear from Microsoft what changes they made to the XIRR function. They certainly didn’t spare any verbiage about the plentiful changes to some of the statistical functions. I guess more people have been complaining about the statistical functions.