A flexible work schedule of less than 40 hours a week used to be considered part-time.  Today, worker advocates in the District have another word for it: Unfair.

Legislation under consideration by the D.C. Council would require employers to provide schedules three weeks in advance and penalize them for changes that happen after that. It’s designed to reduce scheduling variability in the retail and restaurant industries, but our new analysis of the proposal, based on government data and interviews with 100 affected businesses, suggests caution is necessary before proceeding.

The proposed legislation for the District is based on a similar ordinance enacted last year in San Francisco. The District’s law would cover restaurants that are part of a chain with 20 or more locations nationwide and retail businesses with five more or locations across the country. In addition to the penalties for schedule changes, the bill would require these employers to offer additional work to part-timers before hiring more staff.

To determine the legislation’s impact, we first used two different Census Bureau data sets — the American Community Survey and the Current Population Survey — to create a profile of the affected part-time employees at the District’s restaurant and retail businesses. A few conclusions emerge: While nearly 70 percent of the District’s workforce has a four-year college degree or more, just one in five of these 11,500 part-timers has the same. Nearly 40 percent have a high school degree or less, and many of them (27 percent) are active students.

Given these characteristics, it’s perhaps unsurprising that just one in seven (14 percent) of these part-timers is estimated to be working that schedule involuntarily. (In our survey of D.C. employers, we found a similar result: 70 percent of surveyed employers indicated that the vast majority of their part-time staff was only seeking part-time work.)  These are important insights: If the workers in question are mostly working a part-time schedule because it fits their lifestyle needs, then legislation that adversely affects this flexibility would hurt the people it’s supposed to help.

Unfortunately, that’s exactly what our survey of affected businesses suggests will happen.

Businesses were most concerned about the provision that requires four hours of pay for any schedule change made with less than 24 hours notice. More than 70 percent of businesses indicated that it would be difficult to comply with this law; for full-service restaurants, that number reached 95 percent.  Majorities of employers were also concerned about a requirement to provide schedules three weeks in advance and to provide an hour of pay for shift changes made after that.

To adapt to the new costs and regulatory burdens imposed by the law, D.C. retailers and restaurants anticipated taking a few steps. Nearly three of four respondents said they’d offer less flexibility to make schedule changes. Half of surveyed employers indicated they would offer fewer part-time positions and change the hiring composition of full-time vs. part-time employees. These consequences may be intended by the law’s proponents, but it seems likely that employees who are voluntarily working part-time won’t appreciate them.

Perhaps because of the nature of the affected businesses, this bill promises to create unique hardships, even compared with other hotly debated policy proposals. We asked employers about the difficulty of complying with a series of the District’s employment current or proposed requirements, including an $11.50 minimum wage, a 16-week paid leave plan and paid sick leave. Thirty percent of employers indicated that this scheduling ordinance would be the most difficult to comply with — a greater percentage than any other proposal.

D.C. Council members should bear this in mind: In an attempt to create fairer schedules, they may create consequences that are deeply unfair for the city’s part-time workforce.

Yelowitz is an associate professor at the University of Kentucky. Corder is the President of Corcom and an adjunct professor at Carnegie Mellon University. Their research was supported by the Employment Policies Institute.