Dive summary:

• The National Association of Home Builders/First American Improving Markets Index (IMI) was created to track the recovery from the recession, and this month it hit its highest point so far, with 291 out of 361 metro markets in the U.S. qualifying as "improving."
• The IMI looks at three criteria –  housing permits, employment and house prices – and scores an area getting better if all three stay on an upward path from their lows for six straight months, so areas can get on the listy, then fall off if one of those criteria trips them up, then qualify again later.
• In September, 242 metros that had been on the August list stayed, 49 markets chalked up their sixth months and joined, and five were dropped.

From the article:

“The dramatic increase in markets qualifying for the IMI in September was partly due to a recent improvement in the way that Freddie Mac measures home prices, which resulted in stronger gains than previously reported,” noted NAHB Chief Economist David Crowe. ...