Several big banks on Wall Street reported strong earnings this week. JPMorgan, Goldman Sachs and Morgan Stanley beat expectations during a time much of their workforce was at home. Yet the same firms have been aggressive about getting staff back to the office. What gives?

Unlike some leaders in tech, the titans of finance haven’t exactly embraced remote work, said Robert Pozen, a senior lecturer at MIT who worked in investment banking. It’s partly because so much of the work is built on relationships, “and maintaining the relationship will be improved if you’re face-to-face,” Pozen said.

Banks have also relied heavily on in-person observation to train entry-level workers, Pozen added.

Not all banks have taken such a hard line on returning to the office, and the diverging work-from-home policies could become a factor in attracting talent, said Harvard business professor Tsedal Neeley.

“We’re already seeing this in many organizations where the competitive edge is to say: flexible work is available here,” Neeley said. That could be important for attracting workers from the tech sector, Neeley added, who are increasingly sought after in finance.