Global Evidence of a Global Housing Bubble?

Reader MA is quite convinced that the entire world is experiencing a housing bubble. Here are two more items he sent, supporting his contention.

KOREA
Housing market experts are voicing their concern that a housing bubble is spreading throughout the entire nation.

... The local standard to judge bubbles is the "jeonse ratio," the ratio of the market housing prices to the prices for jeonse, or rentals with a huge lump-sum deposit, which is the most common form of housing here.

"The jeonse ratio is dropping is because the current real estate market is dominated by money games on imaginary demands," LG Economic Research Institute analyst Kim Sung-sik said, referring to people's tendency to snap up properties whose prices are expected to rise soon.

and this one from the Times Online:

In three years house prices have rocketed in South Africa by 95%, in China by 68%, in Australia by 56% and in America and Thailand by 29%. In Britain they rose 50%. The world has never seen a boom of such breadth and scale.

“Eighteen months ago you could have bought a studio in the Jumeirah Beach residence for £40,000,” said Paul Taylor of Dubai Select, a property marketing company. “Now you could sell it for £150,000.”

If the housing bubble is so widely recognized, and it is, indeed, a global phenomenon, why hasn't it burst, yet? One possible answer is that it is already slowly deflating.

Perhaps what MA (along with others) is concerned about, though, is that a small change in fundamentals could lead to a big change in prices. See the really nice piece Alex Tabarrok has written about housing prices at the Marginal Revolution.