Zillow economist Stan Humphries brings the bad news, noting that after several months of increasing prices, December saw home prices in 29 of 143 markets either flatten or decline. (New York, for instance, was flat, breaking a six-month run of rising prices.) An additional 21 markets saw prices continue to increase, but at a slower rate than in previous months. Could the dreaded double dip be on its way? In a word, yes. Also, if you own property in Las Vegas, well, we’re sorry.