When the market plunged, doomsaying economist and NYU Stern professor Nouriel “Dr. Doom” Roubini saw his fortunes rise. He wrote a best-selling book, made cameo appearances in several movies, and became a regular presence on television, on the lecture circuit, and at parties, where he is inevitably surrounded by the sort of ladies most economists only dream about. But even Roubini has been victimized by the housing-market crash he so famously predicted: Though he recently plunked down $5.5 million for a new penthouse, he can’t seem to sell his old pad in Tribeca, for which he was asking $1.79 million. (He paid $860,000 in 2002) and recently took off the market to rent. We wonder what he thinks the reason is: the double-dip, or the wall vaginas?