June 28 (Reuters) - The United States cannot afford a "boom and bust cycle" in the housing market that would threaten financial stability, Boston Federal Reserve Bank President Eric Rosengren told the Financial Times in an interview published on Monday. "It"s very important for us to get back to our 2% inflation target but the goal is for that to be sustainable," Rosengren told the newspaper. "And for that to be sustainable, we can"t have a boom and bust cycle in something like real estate."