The ECB’s move will have other benefits, too, in particular if it helps pep up the moribund European economy. QE has prompted a swift fall in the value of the euro, which is good news for exporters. Some of them might decide that, thanks to rising foreign demand, now is the time to take out a loan to expand. Exports account for more than a quarter of the euro zone’s output, a higher proportion than in other parts of the rich world, so even a small increase will have a sizeable impact.