We’ve all had ’em, all dreaded ’em. Possibly the worst part of office life: the meeting.

But, turns out, maybe it’s okay to hate them, because they can be a huge waste of resources like time and money.

“Our best estimates — and these are pretty educated — are there are 11 million formal meetings every day in the United States. That tallies up to about four billion a year,” says Nancy Koehn, who teaches at the Harvard Business School. “Over half of the people surveyed say about half the meetings they attend are unproductive.”

“So maybe a little more than two billion meetings a year that most people regard a very poor use of their time — that seems like a real waste,” she adds.

And yet despite the loss of productivity, we continue to have meetings.

Koehn says it’s mostly out of routine and habit, and that email has contributed to more meetings because it makes it too easy to invite a whole list of people for a gathering, even if there’s not a good reason for it.

“Whether you could accomplish a goal some other way,” Koehn says, “We just hit send.”

She recommends that if meetings begin and end on time, and if you limit them to a short amount of time to get a stated goal completed, the overall meeting will be more productive.