The only certainty for the world's central bankers is uncertainty

Washington

FROM the immediate possibility of Britain leaving the European Union to the longer-term consequences of ageing populations, the world's major central banks this week just weren't sure what to do next.

Officials from the US, Japan, the UK and Switzerland all opted to keep monetary policy unchanged this week as they await the June 23 Brexit vote and try to make better sense of the deep-seated forces shaping their economies.

"We are quite uncertain about where rates are heading in the longer term," Federal Reserve chair Janet Yellen told reporters on Wednesday, noting that an ageing society and lagging productivity growth s…