Fed's Brainard says caution warranted due to global risks

By Jason Lange and Lindsay Dunsmuir WASHINGTON (Reuters) - Federal Reserve Governor Lael Brainard on Friday warned that raising U.S. interest rates could hit global growth enough to knock the U.S. economy off its current growth path. This could leave the U.S. economy particularly vulnerable because the central bank's benchmark interest rate is already close to zero. "The ability to offset spillovers from adverse developments in foreign economies with conventional policy is constrained, suggestin