Get your tiny violin: Rich running out of mansions to buy [View all]
While housing inventory is falling throughout the country, it's falling especially fast in some of the country's richest ZIP codes. A study from Altos Research, the Mountain View, Calif., real estate research firm, found that inventory in the nation's 90 wealthiest ZIP codes fell 15 percent over the past year, slightly faster than the broader market.
In those areas, inventory is down more than 50 percent. In a swanky part of Carmel, Calif., inventory fell 76 percent in the last year. There were only four homes left on the market priced at $1 million or more as of the end of May, according to Altos.