Who’s the daddy? “IF THEY resented me they didn’t talk to me about it,” says a young German manager at a media firm in Frankfurt. Still, he says it was noticeable that when a subordinate 20 years older than him thanked him for buying lunch he had to swallow twice before adding the word “boss”. Older workers sometimes begrudge being managed by a callow colleague. Precocious youngsters, too, can feel awkward about bossing their elders around. But in Germany a shortage of skilled workers means that such situations are becoming ever more common. The country’s population is projected to shrink. Among rich-world countries, only in six nations including Japan and Greece are populations expected to decrease faster. As more Germans retire, fewer youngsters are entering the workforce to replace them. As a share of the working population the number of 15-to-24-year-olds has fallen by ten percentage points since the 1980s, says the German Federal Employment Agency. Firms competing to retain young talent are tempted to promote them earlier as a result. A paper by professors at the University of Cambridge and WHU, a...