I recently spoke with a 50-ish successful executive at a large media company. She said she never wanted to go back to the office. She loved working from her second home in Miami — or the resort in Mexico she just returned from. She said she was just as productive, if not more, working this way. I asked if she thought the arrangement was equally good for junior staff.

This executive had built valuable contacts, culture and camaraderie by logging many hours in the office with her co-workers while rising through the ranks. There is a lot of grunt work early in a career, but time in the trenches with colleagues, ordering takeout when you work through dinner and going out for drinks afterward is what helps make it bearable. You form relationships that last the rest of your professional life.

The executive agreed that she benefited from spending days in the office when she was younger, and that senior staff had mentored her. I asked if she felt a need to repay that generosity by going back. She thought about it, and then argued that going to the office posed a health risk, so it’s different now.

Going back to work is emerging as a collective-action problem. Older, more established people don’t want to go back and don’t feel it’s necessary to do their jobs. But having them return to the office is important for workplace culture, long-term productivity and for passing skills and influence on to younger colleagues. If these older workers don’t return, there is less motivation for younger people to return, too. And right now not that many people are going back: Office occupancy rates are only at 40% in the U.S., and are even lower in cities like New York and San Francisco.

True, going to the office may feel like a waste of time. It involves putting on nicer clothes and commuting, sometimes for long distances.

Research by Stanford economist Nicholas Bloom and his co-authors estimate that working from home during the pandemic increased productivity as much as 5% (depending on the job), largely from avoiding a commute and having more quiet time. But he explained over email that there can be too much of a good thing: “I see the WFH impact on productivity a bit like going to the gym — great in moderation but problematic in excess.” He is concerned about the long-term impact on productivity from too much working from home. He says you need about three days in the office for many jobs to facilitate creativity, innovation and culture building.

So why not just go back two or three days a week?

Bloom’s survey suggests that’s what most people who can work remotely plan to do. He thinks a hybrid model may be optimal productivity-wise, since it balances saving commuting time with enough in-person time. And the return to the office will probably start that way.

But it may not be sustainable. Eventually, the working-from-home option may become equivalent to the idea that you don’t have to answer your email on the weekend. Technically it’s a choice, but not one you can really make if you want to advance. Showing up every day signals more dedication and offers the opportunity to volunteer for big assignments, or just chat over coffee and decide something important with the other people who showed up that day.