A study of 1 million employees shows what happens when colleagues leave

There’s quitting time, and then there’s quitting time. At some point or another, you’ve probably felt the urge to hang up your hat, toss your phone into the Place de la Concorde, and put in official notice.

For every great employee who moves on from their job, there’s a team left behind that feels the departure. Maybe a teammate was great at their gig, able to balance books or keep projects moving at the speed of a plate spinner. Or maybe they held up a Herculean morale, becoming beloved as a work bestie, a master mentor, or a person who made everybody feel like they were part of something bigger. So what happens when the best employees exit? A new study examines those dynamics.

You might suspect that when great teammates leave, more will follow them. And it’s true: Exits by top performers do set off more departures from their company. But surprisingly, the level of impact (and turnover) depends on exactly how they exit.

To understand how these exits influence the people who remain, researchers from the University of British Columbia and the University of Minnesota looked at more than a million employees across 1,620 large retail stores, measuring comings and goings over 22 months. With access to employee performance records, the researchers identified high and low performers; they also tracked when employees were hired, where, in which position, when they left, and why.

The research measured departures with corresponding turnover rates, and found that the type of employee who left influenced whether others followed them. What separated them was their performance.

If you tend to surround yourself with coworkers who work as hard as you do, you might be more influenced by them than you think. That’s because the researchers also found a link among groups of similar performers: If someone who works and performs as well as you do departs, you’re more likely to head out the door.

The researchers call this a multiplier effect. When high performers leave, more high performers quit. And when low performers leave, well, the low performers still on the job tend to go, too.

Interestingly, the study found different effects on the team left behind depending on whether a top performer quit, was fired, or was laid off. “Each type of exit causes its own distinct level of disruption,” said Sima Sajjadiani, an author of the study, in a release. ​​

The dismissal. Dismissals of star teammates were the least likely to inspire more quits. But in a reversal, when a poor performer—like a toxic teammate or a colleague not pulling their weight—is dismissed, employees are more likely to stay on with their company. “When a bad apple is dismissed,” Sajjadiani said, “other workers feel better and stay longer.”

The voluntary notice. When a great employee quits, other great ones start thinking about moving on, too. “When high performers are leaving and I am a high performer as well, I might think, ‘There are other, potentially better opportunities. Maybe I should leave, too,’” Sajjadiani said.

The layoff effect. The highest rate of departures was correlated with layoffs of top employees. Watching top teammates lose their jobs, despite being excellent at them, disincentivizes other high performers, who might wonder if they’re next—and start looking at other options.