Arguments about whether inflation or deflation poses the bigger risk to the global economy have become more tortured than a Franz Kafka novel over the last year.

Even those at the coalface of capital markets have confessed to being stumped. Michael Faissola, global head of rates at Deutsche Bank, said in late March: "I cannot think of any time in my career when the question of where inflation is going has been harder to answer, or where there has been a larger divergence of opinion."