Ultra low interest rates are causing "huge problems" for Germany, the country's finance minister has said.
"We have an interest rate environment that is causing huge problems for us in Germany," Wolfgang Schaeuble said at a banking event in Berlin.
However, he added that he was not criticising the European Central Bank (ECB), which needed to defend its inflation target.
"A low interest rate leads to a misallocation of resources with all the risks and side-effects that you see when bubbles are forming," he said, adding that there was too much central bank money and debt in the world.
Mr Schaeuble also said that bond buying by the European Central Bank meant countries had less incentive to reform.
In a separate hearing, Mario Draghi, the president of the ECB, said its bond-buying programme would give countries more breathing space to enact reforms. he said the benefits of quantitative easing were already taking effect.