Next time you see a headline in which economists say the housing market's recovery is under way, put an asterisk next to it. That's because national averages mask profound local differences in the speed of that revival. David Crowe, chief economist at the National Association of Home Builders, highlighted those variations last month when he released a map forecasting states' housing production at the end of 2011 as a percentage of their average annual production from 2000 to 2003. Eighteen months from now, Crowe predicts, many Southern and Plains states will rebound to at least 89% of normal production. In contrast, the Great Lakes states plus California, Florida, Nevada, and Arizona will still be running at less than 70%.