Appreciation in real estate about keeps pace with inflation (assuming large samples over diverse geographic areas), so the average real estate investor makes no money from real estate based on appreciation. 

Taking a step back, if you had a diverse portfolio, you would not be sitting on a portfolio of cash.

Here's an article about the 1982 - 1987 oil and gas bust in Houston:Oil Busts Houston To 'Loan Scar' State City Seeks Industrial Diversity For Climb Back Into The SaddleAugust 2, 1987|By John J.

We were able to set-up SD 401Ks, and are now shopping for five more houses which fit our profile (built in the 2000s, very good schools, areas with good and diverse economic opportunities which should appreciate nicely, good rent vs price return, not California).

socialism communism there just words thrown around and mean absolutely nothing, I ask anyone of you on here who have enough money go abroad for a while spend some time in another country and see that the way we describe our political terms are 180 from the way the rest of the world uses the same exact words.America is made up of so many people from such diverse backgrounds that to think were going to find someone who pleases us all is just ridiculous.

Like Brian stated above, there is so much diversity in the art of RE investing/Trading.

Hi colleaguesI've been discussing this subject with a few people, and I get diverse opinions, what are your thoughts:How rent values could be affected by depreciation?

But the Phoenix market seems to me to be way more diverse in terms of job base.

The metro area is huge and diverse, as is the SF Bay Area.  

Though sometimes I wonder if it would be better in the long term if the last of the big manufacturers would just die and let the city redefine itself with a more stable and diverse economy (is this blasphemous?)