The latest in the endless search for “new normal” in the workplace is the idea that the shutdowns that caused people to work from home will lead to a permanent shift away from the office. Gallup polls report that the percentage of people who say they have worked “remotely” roughly doubled from the beginning of the virus-related changes in March until April, up to 62%. The arguments that people will continue working from home even after the pandemic-related restrictions goes like this: It’s cheaper because we can cut down on office space. People also like it: In the Gallup survey, 59% said they would like to keep working this way. And it’s just as productive.

We have seen this movie before.

We have been working remotely for a long time now, starting in my memory in the 1970s when smog in the Los Angeles basin got so bad that driving to work was temporarily forestalled, and so at least some people worked from home. Then as air pollution controls got better, we all went back to the office.

In the 1990s, when big city real estate started to get very expensive, consulting and accounting companies realized that, with so many of their employees on the road most of the time, they were paying for those empty offices. The idea of hoteling was born, later called “hot-desks” in Europe, where those mobile employees just borrowed a desk when they were in the office. This practice does not appear to have grown much over the last 20 or so years.

Now we come to telecommuting, which is just a new term for remote work now that we have internet, which we’ve had for 30 years … . Gallup reported in 2017 that 43% of employees were working remotely at least some time. Taking off early on Friday to finish a report at home is no big deal. Flexi-time—where the employees in a workplace agree on a work schedule that covers the office, gets the work done and helps with their own schedules—works well. If we get more of that stuff after pandemic restrictions are lifted, that would be a good thing. Employees like it, and it seems to work OK.

Related: How to connect remote employees—and have fun

The reason we didn’t get more of this before is frankly because employers let local managers decide when and where employees can have this kind of flexibility, and a lot of them just don’t trust employees when they aren’t being watched. Will that change after the pandemic? I don’t think by much. We will be back in a bad job market where managers will push and employees will do anything to keep their jobs.  The fact that workers like it won’t matter much, and the managers who think you can’t trust employees will not have gone away.

But never going to an office, not having any interaction with co-workers other than by conference call or video links, is not the same thing as telecommuting. The U.S. Census finds a very small percentage of people had been working that way before the pandemic: maybe 5%.

What we know about even occasional work from home is, first, it works best for tasks that are self-contained. Second and related, it makes big demands on performance management so that employees know exactly what they are supposed to be doing, something we are not so good at now. Third, it doesn’t work well for tasks that require close supervision, interaction, cooperation or are team-based.  Fourth, the big advice for trying to manage remote teams—even where people are in offices, just different ones—is to get them together physically as often as you can. That pretty much rules out permanent work from home for most all jobs.

The big savings from working from home comes only if we actually get rid of the offices. There are entire categories of workers who cannot do their work from home even now—frontline workers, service workers, basically all low-wage work—and that is unlikely to change. Remember when we thought retail banking jobs would go away because it was possible to bank electronically? If you need to have a physical presence for frontline workers, there isn’t as much scope for getting rid of office real estate.

Are we really just as productive never coming into an office? If you have completely self-contained tasks, I’m sure the savings on commuting time and so forth might make some workers more productive. Other workers don’t have a great space at home in which to work, and they could be less productive. Most employers now are working at reduced capacity, so it is easy to think that we are being just as productive as before because there isn’t nearly as much to do.

See also: Remote work after COVID-19

HR folks should also keep this in mind: We do so many things in our workplaces to make employees productive: quiet and attractive offices, free coffee (!), physical manifestations of organizational culture, IT and administrative support, and so forth. Think how depressing it would be for those in charge if it turned out that you could take everything we are doing away, just send people home and it would work out better.

Here is what I can imagine happening: The CFO says, “OK, we have people who are working at home pretty well without a lot of supervision? Great. So, why do they need to be employees at all? Let’s make them contractors and save on benefits. Then they could keep working from home.” Not exactly what we were expecting but more likely.