It is also important to mention prediction regarding prices of real estate (which also influence rent). For example, prices of real estate in Japan are still falling down - nearly 20 years of constant decline [1].

There were articles in 2007 [2], how Japan's real estate crash may finally end after 16 years, but oh well.. we know happen in 2008.

[1] http://blogs.reuters.com/felix-salmon/2010/01/12/house-price... [2] http://www.generationaldynamics.com/cgi-bin/D.PL?xct=gd.e070...