Former Federal Reserve Chairman Alan Greenspan has said he expected U.S. house prices will begin to stabilize in the first half of next year. 'Home prices in the U.S. are likely to start to stabilize or touch bottom sometime in the first half of 2009,' Greenspan said in an interview with the daily The Wall Street Journal. However, he warned that even at bottom, 'prices could continue to drift lower through 2009 and beyond.' Greenspan also acknowledged that a government backstop for the shareholder-owned, government-sponsored enterprises, or GSEs, was unavoidable. 'There's no credible argument for bailing out Bear Stearns and not the GSEs,' he said, referring to the two troubled mortgage giants Fannie Mae and Freddie Mac.