Still, that so many young people are working from home is a reversal of long-standing habits, said Julia Pollak, a labor economist at ZipRecruiter, the online employment marketplace. “The norm for so long is that remote work in office jobs has been reserved for the oldest and most senior and most trusted,” she said. “It’s interesting how quickly young workers have embraced this.” When they work apart, younger employees lose chances to network, develop mentors and gain valuable experience by watching colleagues close-up, veteran managers say. In some cases, older millennials like Jonathan Singer, 37, a real estate lawyer in Portland, Ore., find themselves making the case for returning to the office to skeptical younger colleagues who have grown accustomed to working from home. “As a manager, it’s really hard to get cohesion and collegiality without being together on a regular basis, and it’s difficult to mentor without being in the same place,” Singer said. But persuading younger workers to see things his way has not been easy. “With the leverage that employees have, and the proof that they can work from home, it’s hard to put the toothpaste back in the tube,” he said. Fearful of losing one more junior employee in what has become a tight job market, Singer has allowed a young colleague to work from home one day a week with an understanding that they would revisit the issue in the future.