Its hard to track. I know with my short sales, I usually have a handful of backups so they usually dont go back on the market. When they do its usually because the lender came back with some terms and I’m looking for a specific kind of buyer to meet them.
As for the pendings my guess would be 20 to 30% go back on the market. But while some are going back on the market others are coming off the market.
Here’s one way of looking at it and bear in mind I’m making this up as I go. Most pendings that close do so in about 30 days. So thats about 3000 per month. I would guess that about 20 to 25% take longer so thats another 1,000 or so (5000 pendings X 20% = 1000???). That gets us to about 4000. So its probably a fairly reasonable assumption that 70 to 80% of pendings close. Of course many that fall out will re-sell to another buyer.
As for appraisal issues, while they exist I dont see them as a major portion of the fall outs. Most fall outs involve buyers changing their minds followed closely by financiang problems.