I've read that there's a year's supply of unsold new homes. Where does that number come from? Self-reporting by large builders/developers?
The numbers come jointly from the US Census Bureau & HUD.
Here is a link that might be useful: New Home Sales
Those are some verrrry interesting tables, albit gloomy ones. The increase in inventory is 28.8% year over year (Feb. 2008/Feb. 2009). Months on market are creeping up too -- no surpirse.
Also interesting, the authority's disclaimer that it takes FIVE MONTHS to extablish a trend in new home sales.