Ben Bernanke disappointed those who hoped his speech at the central bankers’ conference in Jackson Hole would signal a fresh round of quantitative easing. The US Federal Reserve chairman ruled nothing out, however. He acknowledged the recent run of gloomy economic news, and said the next meeting of the Fed’s policymaking committee would take an extra day to discuss the “merits and costs” of monetary stimulus. Meanwhile, he called on Congress to improve its fiscal policy and attend to issues that lie outside the Fed’s purview.

Mr Bernanke is right that the Fed cannot carry the whole burden of economic policy. The reason is not that there are no monetary policy tools left. As Mr Bernanke has often stressed, the Fed can apply more stimulus if need be, even with interest rates close to zero – most directly through asset purchases, but also by changing the maturity structure of its asset portfolio and in other ways.

But the chairman must contend with dissenting opinions on the federal open market committee. Some of his colleagues worry about rising inflation – with little reason. The Fed also faces criticism from some on Capitol Hill and beyond. The recent attack on Mr Bernanke by Rick Perry, the front-runner for the Republican presidential nomination, is the most notorious example, but far from the only one.