In a multipolar world the dollar's dominance won't last forever

Two big international gatherings took place last week. The one that was held in the Rocky Mountain resort of Jackson Hole was a demonstration of the grip the US has on the global economy. The one that was held in Johannesburg was evidence of the challenge posed to America from the leading emerging market countries. Let's start with Jackson Hole, where Jerome Powell took centre stage. What the head of America's central bank had to say about interest rates clearly mattered for the US, where the economy has so far emerged relatively unscathed from the severest tightening of policy in…