JUST a week after turbulence hit financial markets in China, hitting investor confidence around the world, today the International Monetary Fund released a downbeat note about global economic growth. The IMF pointed to a slowdown in growth across both advanced as well as emerging economies in the first half of 2015, and warned that financial turmoil, slow productivity growth and falling commodity prices will dampen prospects for the rest of the year. Still, the note appears to be sending out a more striking message to policymakers than investors, telling the Federal Reserve and the Bank of England, the two central banks closest to raising interest rates, to hold off any hikes for a little longer. The Bank of England’s rate-setters are due to gather on September 10th, and Janet Yellen will chair the Fed’s next meeting on September 16th. Both are currently considering raising rates for the first time since the financial crisis. But the IMF believes that “in most advanced economies substantial output gaps and below-target inflation suggest that the monetary stance must stay accommodative”. Or, in other words, rates need to stay lower for longer.

There is currently little evidence supporting the case for an immediate rate rise in the United States or Britain. In America, unemployment has fallen steadily since the crisis and growth has been above 3% on an annualised basis for three of the past five quarters. But neither wages nor inflation is putting the Fed under any pressure to act: the prospect of the American economy overheating any time soon appears to be remote. Unit labour costs barely increased in the second quarter, while the Fed’s preferred inflation gauge stood at 1.2% in July, compared with its target of 2%. Similar forces are at work in Britain, where a strong currency and cheap energy are holding inflation virtually at zero.

Central banks should also weigh up the potential effects of raising rates on the rest of the world economy. It is here, especially, that risks abound, particularly as it is neither part of the Fed nor the Bank's mandate. It is not simply China that is causing financial markets to spasm. Emerging-market bond yields have jumped since May, according to the IMF, while dollar-denominated debt is becoming more expensive to service thanks to currency depreciation. Tighter monetary policy in America and Britain would exacerbate these trends, dampening global economic growth further.

The market turbulence of recent weeks is unlikely to dissipate quickly. The IMF’s economists want the European Central Bank and Japan expand their ongoing quantitative-easing programmes, if inflation remains off-target for much longer. This raises the prospect of two of the world’s biggest central banks moving in one direction and another two moving in the exact opposite. The IMF, at least, is doubtful the global economy could take this in its stride. Gyrating stockmarkets suggest that investors may believe this too.