The Case-Shiller 20-City Index saw another strong increase in July, this time rising 0.9 percent. The index rose 1.1 percent in June and has now increased at a 13.1 percent annual rate over the last three months; although it is still down by 4.1 percent over the last year. But unlike in June, when all 20 cities showed house price increases, 18 of the 20 cities had price increases in July, with only Phoenix and Las Vegas showing modest price declines (0.1 percent and 0.2 percent, respectively).

The strongest factor pushing up prices is the reversal of the sharp price declines in bottom-tier home prices in the period immediately following the end of the first-time buyers tax credit. Recent extraordinarily low interest rates will provide a boost to the market — though the scaling back of Fannie and Freddie’s higher mortgage limits will be a factor going in the other direction — but this upward bounce is surely coming to an end. The inventories of new and existing homes for sale remain above normal levels. In addition, there is a large amount of inventory not showing up on the market, which is best demonstrated by the near-record vacancy rate nationwide.

For more, read the newest Housing Market Monitor.