In recent years there have been long periods of price trends in [the housing] market, and researchers have repeatedly demonstrated inefficiencies. This suggests a market driven by positive feedback ["momentum"], resulting in price trending, high volatility, and inherent instability. And, contrary to what many have argued, it is not likely the best choice as a central driving force behind our economic welfare. We would do well to reduce our reliance on housing as an economic engine. For the same reasons, it probably does not make sense to view housing as an investment that dominates most household portfolios.
-from Liang, Shelly X. PhD, Research Fellow, in "Momentum Amplifies Swings in Housing," AIER Economic Bulletin, Vol. LII, April 2012.