Ashona Osborne doesn’t mind staying late at work when it gets busy. The problem is she has to arrange for someone to pick up her 5-year-old son from school, so she needs to be able to make some calls.

Instead, like many low wage workers, Ms. Osborne, 23, of East Hills, isn’t allowed to use the phone when she is on the clock at the Arby’s restaurant where she works. That adds to the stress of her irregular schedule.

“They believe that, once you are on the clock, your personal life is on hold,” she said. Since she needs the job, she is willing to do whatever she can to help her employer.

It’s not just low wage workers dealing with unpredictability. Workers at all income levels have to cope with schedules that suddenly change.

But the impact of such schedule changes — which have become more common in some businesses trying to manage the payroll as efficiently as possible — is starting to gain attention from both academics and from government officials looking at making sure businesses follow rules meant to protect employees.

“It’s pretty widespread that work is not predictable or stable over a day,” said Lonnie Golden, a professor of economics and labor relations at Penn State University’s Abington campus.

Mr. Golden put out a report recently that found that when irregular, on call, split and rotating shifts are factored together, about 17 percent of employees have unstable work schedules. Those workers include 16 percent of the hourly workers, 12 percent of workers who are paid salaries and 36 percent of workers who are paid on other bases, such as contract and temporary.

The difference between hourly and salaried workers is that hourly workers are typically denied the ability to step away, handle the conflict and then get back to work, said Mr. Golden.

Mr. Golden’s report found that even though both salaried workers and hourly workers experience work-family conflict when they have to work extra hours, it is the hourly workers who experience additional stress.

He said workers who are paid salaries tend to have better supports and easier access to the means of rescheduling other aspects of their lives.

Having workers remain on call is one of the new ways that employers have found to cut labor costs. Now, low wage workers are told they will be on-call to staff busy periods — if retailers and fast-food establishments get busy — but are not paid if they’re not called.

The practice of placing workers on call is disruptive to both their lives and their budgets, said Tsedeye Gebreselassie, an attorney for the National Employment Law Project in New York City.

When workers are on call, they can’t predict or budget their income; they may have to pay for childcare that they may not need; and they may travel to work only to be sent home, she said.

“What good is $15 an hour if you don’t get enough hours?” she asked, referring to the other prong of the current national fight for low wage workers, that for a minimum wage of $15 an hour. The current federal minimum wage is $7.25 an hour.

“In large part, businesses know what their labor needs are,” Ms. Gebreselassie said.

New York is challenging such scheduling practices. Eric Schneiderman, the state attorney general, wrote letters to 13 companies earlier this month asking for information about their scheduling.

The letter stated that his office has “reason to believe” they are using scheduling software in which the employees have to check in by phone or text to find out whether they are needed that day. Placing employees on call without pay is illegal in New York. Pennsylvania does not have the same requirement.

Companies that received the letters include Gap Inc., which owns the Gap, Old Navy and Banana Republic retail chains; Target; Sears, which also owns Kmart; TJX Co., which has the T.J. Maxx, Marshalls and Homegoods stores; and Ann Inc., which operates Ann Taylor stores.

Unpredictable scheduling can also have other consequences for employees. 

Ms. Gebreselassie said workers have opportunity costs associated with being on call. They have to foresake a possible second job and college classes just to be able to get to work at a moment’s notice.

Ms. Osborne said her own schedule has been very hard to predict. Some weeks she has worked 35 to 40 hours.

But one recent week, she was scheduled to work 12 hours, while the next week her schedule had her on 5.5 hours.

Ann Belser: abelser@post-gazette.com or 412-263-1699.

First Published: April 26, 2015, 4:00 a.m.