I think that the economy is finally taking a minor upturn, and since people on the whole are optimistic creatures, they're looking to replace what they may have lost in the worse times which are now hopefully behind us. Others are actually downsizing homes in an attempt to relieve themselves of huge debt loads from albatrosses of houses that they thought they "needed".
I don't really understand the question, but if the market is booming somewhere... That's not everywhere. Even if it is growing, the same sub prime loans are being used. Be prepared for another housing crash. It's just a matter of time.
Poor management and investing by banks, allowing people to buy over priced houses without enough income, and of course real estate agents pushing up the prices to get a better commision.Also a housing shortage can be a factor by which governments refuse to release extra land for the higher demand of property.