One of the case studies talks about an investor who liquidated his portfolio down to 40% LTV towards the end of the boom.Also important to note I think is that values can continue rising in the beginning of the slump, where things like rents, and GDP are coming down while active listings are rising.

And depending on the location, rents could rise and make the numbers on the spreadsheet look a little better.  

It also has some character - it is located in a national historic district in an area that had seen decline in the past but has been on the rise for years now with some properties converted to bed and breakfasts and other converted to commercial use such as law offices and doctor's offices.

here's an article that just came out today regarding LA rents and a study done by the university of southern california. rents expected to continue to rise for at least two more years.http://la.curbed.com/2016/4/12/11414618/los-angeles-rents

Interests rates are low but steadily rising.

Factor that in, along with a more than likely rising market.

This could be a situation where the rents aren't keeping up with rising property values, or perhaps you're not renting the house at current market value.

I'm currently looking to purchase my first property and I'm being squeezed out of Seattle with the rising housing costs.

Once the appreciated value of a property rises above a descent rent to value ratio investors know to sell.

BTW I bought a huge deal in Dallas in 2009, the thing didn't really bring much cash in ever but thank God for that fast rising Dallas market.