Famed economist Gary Shilling is not one of them—you could call him notably bearish on housing.

In fact, he expects prices to drop another 20 percent from here and doesn't think we will see a bottom in the market for another several years.

The main reasons Shilling is so pessimistic: There is a huge supply of excess inventory not being accounted for, and prices still have not fallen to anywhere near long-term historical averages.

In his monthly INSIGHT client newsletter, Shilling outlined his bearish housing thesis and used several charts to illustrate why he thinks there is no bottom in sight for the U.S. housing market, and more pain is ahead for American homeowners.