Property bottoming out in 2010?

Source: My Paper, 10/2/9, p.A8
Headline: Property bottoming out in 2010?

Quote1:
Mr Phil Anderson, who calls himself a renegade economist, ... confidently calls a property market bottom next year. ...

Comment1:
The conclusion is set out: Property bottom in 2010. What is the supporting argument?

Quote2:
Mr Anderson bases his prediction on an 18-year cycle which he says has manifested itself in the US since 1800.

Comment2:
The supporting argument is an 18-year cycle in the US. What is the supporting argument for the 18-year cycle?

Quote3:
Since then, there had been peaks in land sales or real estate speculation in 1818, 1836, 1854, 1888, 1908, 1926 and 1944. The peaks were followed by downturns or depressions, typically lasting four years. World War II disrupted the pattern. But the cycle resumed in 1955. The real estate market in the US again peaked in 1989 and bottomed in 1991. And 18 years later, in 2006-7, it hit another high. According to Mr Anderson, the market is now into the third year of downturn, so by next year it should bottom.

Comment3:
The supporting argument is inductive: a series of peaks at 18-year intervals, followed by four year downturns. An inductive argument says that if the past is X, the future will also be X. But look at the years. The intervals 1854-88 and 1888-1908 were not 18-year intervals. We have no information on the downturns.

Quote4:
The next boom, peaking around 2024, will be huge because hundreds of millions of Chinese will enter the market for the first time, he said.

Comment4:
The inductively observed pattern occurs in the US. No reason is given for extending it to China in 2024, nor is such an extension intuitively true.

Quote5:
Mr Anderson is confident the cycle will repeat itself as long as land is tradeable and in private hands.

Comment5:
"Land is tradeable and in private hands" leads intuitively to market ups and downs; but not to 18-year cycles. That needs additional argument.