Realtors' Home Sales Numbers Exaggerated?

Calculated Risk did a little digging....

I've been discussing the National Association of Realtors (NAR) existing home sales data with several analysts. As an example, Keith Jurow has been sending me data from local areas, and also calculations based on data from Inside Mortgage Finance suggesting that the NAR existing home sales data is overstating sales. I've also looked at other sources, and I think the NAR started over estimating sales in 2006 or 2007 (perhaps by 5% or so in 2007), and the errors have increased since then (perhaps 10% or 15% or more in 2009 and 2010). I expect the NAR will revise down sales for these years in the not too distant future...

Not good news.