However, the occasional backed toilet, or dead light bulb (etc.) is not as predictable.

You could be maybe a football field away from a Starbucks and still end up in one of the few bad pockets.

For that as a quick comfort level I like 3 months of rent saved, but I do a detailed calc looking at building a fund for predicted replacements of things like roof, furnace, any other item over $500.

Many do not predict another 07-08 collapse as that was the perfect storm of several causes.

David and others mentioned it has little to do with predicting the future total potential returns historically.

If you are doing standard stamps that is a lot harder to predict when they will arrive but you can send more mail for the same cost.

A specialist advised me to wait a bit because everyone is predicting a price drop. 

I won't predict where values will go in the next few years.

I agree that this is one of the strangest situations I have ever seen.I have tried to figure out what would motivate a bank to follow this predictable path not once but multiple times.Maybe it is just wishful thinking on the part of the lenders... as they all seem to still have their head in the sand regarding any sustainable recovery and home prices stablizing let alone increasing.

I do agree that, in order for a local market to have house values drop 35%, something devastating would have to occur, and usually that would be predictable.