Case-Schiller Reports 10.9% Increase In March

[John Thedford]

I copied and pasted this from Naples Daily News:

Home builder stocks rose early Tuesday after the Standard & Poor's/Case-Shiller survey found that U.S. home prices rose 10.9 percent in March, the most since April 2006. A growing number of buyers are bidding on a tight supply of homes. The survey was released before the stock market opened.

Is this supply and demand driven, or is it goverment intervention?