Christopher J. Mayer, a professor of real estate at Columbia Business School, said the price increase happened because foreclosed homes, which were usually among the cheapest, were no longer widely available. In the Phoenix area alone, the number of distressed homes on the market fell by 81 percent in the year ended in April, and the number of foreclosures fell by 62 percent, the report showed.

One of Arizona's most prolific builders, Maracay Homes, bought 13 pieces of land for development over the past 30 months in Phoenix and Tucson, where homes have been rising at a fast clip. As of June 1, the company had sold as many homes — 242 — as it did in all of last year, its president, Andy Warren, said.

Over all, builders have on average a two-and-a-half-month supply of new homes in their subdivisions.