Global bond burn from Brexit may now force fiscal response

By Mike Dolan LONDON (Reuters) - A slump in long-term interest rates since Britons voted to quit the European Union is the clearest financial market verdict on the global impact of 'Brexit' - yet another body blow to world growth that may now need a game-changing policy response. With many governments now able to borrow for next to nothing for decades into the future, economists this week called on them to stop leaning on exhausted central banks and use record cheap borrowing costs to kickstart