NEW YORK CITY-In the packed Grand Ballroom yesterday at the Waldorf Astoria Hotel, economist Nouriel Roubini delivered a lunchtime keynote speech at REIT Week 2011 that centered on the positives and negatives impacting the global economic recovery.

“The global economy is a glass that is half full and half empty,” Roubini, a professor of economics at New York University and the chairman and founder of Roubini Global Economics, told the crowd. The positives, he said, include a global economic recovery that is, in fact, becoming an expansion and a corporate sector that streamlined during the downturn. “There are many positive trends,” he said, “but there are also a number of downsides.”

Those downsides include sovereign risk that remains quite high globally, with large amounts of public debt. Also the Eurozone, though causing less concern this year than last, continues to be troublesome, particularly the smaller countries on the fringe of the union.

“If I were to ask myself what are the commonalities of these countries are , I would make the following observation: to different degrees, all of them have large deficits,” he said, adding that “many of the financial systems of these countries are damaged.”

As the government starts deleveraging and rolling back stimulus programs, Roubini said that he anticipates a similar deleveraging to occur in the housing sector. “One sector of the market that is already double-dipping is the housing market, residential real estate,” he said. Before all is said and done, Roubini--dubbed Dr. Doom for his spot-on prediction of the housing bust--told the audience that “almost 50% percent of houses are going to be in negative equity.”