in the late 1800s, an Italian economist named Vilfredo Pareto theorized that in most countries about 80% of the wealth and power was controlled by about 20% of the people. He calle this a "predictable imbalance,", which eventually became known as the 80:20 rule.

 http://management.about.com/cs/generalmanagement/a/Pareto081202.htm

There is more demand in good location from RE investment standpoint. But this demand is slashed by affordability, i.e. PRICE. That's why pple prefer REOs today. and million $ houses have been sitting on mkt for a long time.

富人毕竟少啊！ 可负担房屋，好买好卖, Bear in mind one has to do business w/ majority of people (80-90%) who are the poor. Size does matter.

 
The 80-20 Rule also tells us  only 20% of people’s work contributes to 80% of GDP.