Unpredictable schedules are so disruptive to the lives of employees that even 30 days of high shift variability in a year increases the chances a worker will quit by 20%, according to a new study from Wharton experts.

Employers use just-in-time scheduling to cover peak demand and raise both productivity and profits, but they may want to reconsider such policies in light of the research, which points to schedule volatility as a major factor in employee turnover.

“Operationally, a just-in-time approach sounds like a good thing, but that’s assuming it’s not going to lead to costs elsewhere,” said Wharton professor of operations, information and decisions Hummy Song, co-author of the study.  “When you think of all the costs associated with high rates of turnover and quitting — the recruiting, the training, and the time it takes for new hires to ramp up their productivity — it’s quite substantial.”

It’s also a cost that most firms don’t appear to be taking seriously, the scholars said, based on their interviews with industry leaders and a wide review of the literature.

“We think companies are not internalizing the implications of schedule volatility on turnover,” said Alon Bergman, co-author and Wharton assistant professor of health care management. “When large corporations think about changing the benefit structure or the pay, they make calculations to think about how that could affect turnover. But nobody quantifies the impact that schedule volatility has on workers’ decisions to quit.”

The study, titled “’I Quit’: Schedule Volatility as a Driver of Employee Turnover,” was published in March in the journal Manufacturing & Service Operations Management. It was also co-authored by Guy David, who is a Wharton health care management professor and chair of the department.

In their paper, the professors examined data on salaried, full-time nurses in the home health care industry. But they believe their findings directly apply to other sectors with shift work or with salaried employees who conduct field visits, such as sales representatives. The research is especially meaningful on the heels of last year’s Great Resignation, when more than 4 million U.S. employees quit or changed jobs, and in the current tight labor market.

“We started this project before ‘Great Resignation’ was even a phrase. To our surprise, it was very interesting to see over the course of our work how widespread these issues of turnover became,” Song said. “Alon and I care about doing work that is practically relevant, and that’s one of the reasons we wanted to study this. As we got deeper into the pandemic and saw a lot of industries struggling, it brought the relevance to the forefront.”

“We think companies are not internalizing the implications of schedule volatility on turnover.”— Alon Bergman

The Need for Work-life Balance

For the study, the professors partnered with one of the five largest home health care agencies in the country that employs 2,100 full-time and 1,000 part-time registered nurses in 36 states. They analyzed more than three years’ worth of human resources records, time-stamped activity logs, and other data to determine voluntary quit rates among nurses who conduct home visits.

Schedule volatility results in high turnover because it’s detrimental to work-life balance. The professors said it can be challenging for managers to recognize the toll that volatility takes on employees when they are hyper-focused on meeting productivity and profit goals. Even for professions in which shift work is the norm, like home health care, too much instability is exhausting and leads to burnout.

“It’s the same narrative again and again. It’s not knowing when you are going to come home, not knowing if you’ll be able to drive your children to school. For many workers, understandably, this is beyond what they want to take on,” Bergman said. “We definitely think this an aspect of work that, if you alleviate, you’ll be able to remove some of this tension.”

Song said unpredictable shift work is particularly burdensome to women, who traditionally bear more of the responsibility at home. For many women in this study, they may also be working two jobs to make ends meet.

“We still live in a world where more moms do school pickup,” she said. “When your day at your home health job becomes unexpectedly longer because of extra visits, that makes it harder to pick up your kids or make it on time to another job.”

“We started this project before ‘Great Resignation’ was even a phrase. To our surprise, it was very interesting to see over the course of our work how widespread these issues of turnover became.”— Hummy Song

Three Alternate Approaches to Creating Staff Schedules

The professors offered three alternative policies for home health care firms to retain nurses through reduced schedule volatility, and they said the policies can be translated to fit other sectors. Leaving supply and demand fixed, they ran simulations to calculate the net change for each policy:

1. Spread each nurse’s visits evenly across their work week.

In health care, emergency visits will always arise, but a more even distribution will minimize the disruption for nurses. The professors called this method “inter-temporal smoothing through redistribution,” and it reduced schedule volatility for full-time workers by 34%.

2. Spread the day’s visits evenly across all the nurses who are working that day.

For example, instead of assigning eight visits to Nurse A and two to Nurse B, they both get five. This is called “cross-sectional smoothing through redistribution,” and it reduced schedule volatility for full-time workers by 20%.

3. Transfer excess visits to part-time nurses whenever possible.

This is called “cross-sectional smoothing through offloading,” and it reduced schedule volatility for full-time workers by 11%.

“We find that each of these policies is able to meaningfully reduce schedule volatility and reduce the rates of voluntary turnover, i.e., quitting,” Song said. “It suggests that using different ways of scheduling as a lever seems to be promising.”

The professors acknowledged that there will be operational constraints on what companies can do, but the idea is to include employee well-being in the larger goals.

“We’ve looked at labor force data across industries, and we find a strong correlation between low schedule predictability and turnover,” Bergman said, citing hospitality and retail as having the highest rates of both volatility and turnover. “This notion is not limited to home health care. These are the same types of complaints you hear across industries, and that links back to burnout.”