Over the decades, a lot of really stupid management fads have come and gone, including:

Six Sigma, where employees wear different colored belts (like in karate) to show they've been trained in the methodology. Stack Ranking, where employees are encouraged to rat each other out in order to secure their own advancement and budget. Consensus Management, where all decisions must pass through multiple committees before being implemented.

It need hardly be said that these fads were and are (at best) a waste of time and (at worst) a set of expensive distractions. But open plan offices are worse. Much worse. Why? Because they decrease rather than increase employee collaboration.

As my colleague Jessica Stillman pointed out last week, a new study from Harvard showed that when employees move from a traditional office to an open plan office, it doesn't cause them to interact more socially or more frequently.

Instead, the opposite happens. They start using email and messaging with much greater frequency than before. In other words, even if collaboration were a great idea (it's a questionable notion), open plan offices are the worst possible way to make it happen.

Previous studies of open plan offices have shown that they make people less productive, but most of those studies gave lip service to the notion that open plan offices would increase collaboration, thereby offsetting the damage.

The Harvard study, by contrast, undercuts the entire premise that justifies the fad. And that leaves companies with only one justification for moving to an open plan office: less floor space, and therefore a lower rent.

But even that justification is idiotic because the financial cost of the loss in productivity will be much greater than the money saved in rent. Here's an article where I do the math for you. Even in high-rent districts, the savings have a negative ROI.

More important, though--if employees are going to be using email and messaging to communicate with co-workers, they might as well be working from home, which costs the company nothing.

In fact, work-from-home actually saves money because then employees can live in areas where housing is more affordable, which means you can pay them a smaller salary than if you force them to live in, say, a high-rent district like Santa Clara, California.

So there it is. Companies have spent billions of dollars to create these supposedly-collaborative workplaces and the net effect has been for those same companies to suffer billions of dollars in lost productivity.

What can you do about it? Well, if you're a business owner, just say no, or, if you've already drunk the Kool-Aid, admit you've been snookered. Re-implement work-from-home and convert your open plan office into a collection of private spaces.

What if you're just a worker-bee? Well, tread lightly. As a general rule, bosses don't react well when told they've made an expensive, dumb mistake. There are also some folk at your workplace whose careers are now tied to the "success" of the office redesign.

So, if you really want to try to change things, you'll need to deal with denial and cognitive dissonance. As Upton Sinclair might have said: "It is difficult to get people to understand something, when their salary depends on their not understanding it."