By Dan Weil The S&P; 500 has slid 6% so far this year, and the 10-year Treasury yield has climbed 115 basis points. The fear of Federal Reserve interest-rate increases have helped send stock and bond prices down in recent months. The S&P 500 has slid 6% so far this year, and the 10-year Treasury yield has climbed 115 basis points. But for the Fed to get inflation under control, the carnage will have to get worse, William Dudley, former president of the New York Federal Reserve Bank, wrote in a column on Bloomberg. Consumer prices soared 7.9% in the 12 months through January. “To be effective, …