Former Fed Chair Alan Greenspan sees No Barriers to Prevent Negative Treasury Yields. Former Federal Reserve Chairman Alan Greenspan says he wouldn’t be surprised if U.S. bond yields turn negative. And if they do, it’s not that big of a deal. “There is international arbitrage going on in the bond market that is helping drive long-term Treasury yields lower,” Greenspan, who led the central bank from 1987 to 2006, said in a phone interview. “There is no barrier for U.S. Treasury yields going below zero. Zero has no meaning, beside being a certain level.” Joachim Fels, global economic adviser at Pacific Investment ... (full story)