Four years after the City of Philadelphia first mandated a $12-an-hour minimum wage for its contractors and subcontractors, Mayor Kenney is asking for more.

Councilman Mark Squilla plans to introduce a bill Thursday on the mayor's behalf to raise the minimum wage to $15 an hour incrementally over four years for its workers and city contractors and subcontractors. Kenney will formally announce the bill at a news conference Wednesday afternoon.

The city does not know how many workers employed by contractors and subcontractors would be affected by this law, but mayoral spokesman Mike Dunn said most of the city's spending on professional services contracts goes to social service agencies, so the change would most likely impact those workers: For example, after-school aides and custodians.

But the bill could also affect others, from the staffers at the city's animal-control contractor to, most visibly, wheelchair attendants, cabin cleaners, and baggage handlers at Philadelphia International Airport. They recently ratified a contract that would give them up to $13.60 an hour in two years.

"Poverty works its way into households in insidious, subtle ways — including when residents discover that their hard-earned dollar buys less," Kenney said in a statement, describing the law as a solution to the city's "pervasive poverty." He encouraged employers to follow the city's lead.

‘Municipal socialism’

It's a bill that's very of the moment, coming on the heels of the nationwide, SEIU-backed "Fight for $15," which focused on fast-food workers and had a local base.

This summer, Gov. Wolf raised the minimum wage for state workers and employees of state contractors to $12, with plans to increase to $15 by 2024.

It also fits into a pattern of worker-oriented laws passed by City Council in the last decade, including laws mandating paid sick leave, increasing penalties for wage theft, and barring employers from asking about wage history in an effort to close the gender wage gap, a law that was challenged in court by the Chamber of Commerce. This fall, Council is also set to discuss what's been branded as the "Fair Workweek" bill, which would regulate scheduling practices for retail and fast-food businesses.

On this front, Philadelphia is part of a national trend. Seattle, New York, San Francisco, and other cities are taking action to fight poverty with workplace laws in lieu of any federal movement. Seattle Councilwoman Kshama Sawant has called it "municipal socialism" and it usually comes paired with anger from the business community.

In Philadelphia, it's no different. Rob Wonderling, CEO of the Greater Philadelphia Chamber of Commerce, has decried what he calls Philadelphia's antibusiness legislation and said City Hall is increasingly trying to act as the human-resources department for local businesses. Yet it's still not clear if these laws are truly driving businesses out of the city.

Meanwhile, in Harrisburg, state lawmakers are considering a bill that would stop cities from creating their own workplace rules. State Rep. Seth Grove (R., York) has said these worker-oriented laws cause "multiple human-relations problems and compliance issues."

Why is the city raising the minimum wage for its contractors but not doing it citywide?

Philadelphia does not have the authority to raise the minimum wage citywide because of a state law, said a city spokesperson. (Though in 2014, amid a national push to raise the minimum wage in cities across the nation, advocates, with the backing of some in City Council, pushed the city to investigate the state law to see if it could raise a legal challenge on the issue.)

When a minimum-wage law works, and when it doesn’t

If you want to see an example of the impact of this kind of legislation — and also how it can fall short, the airport workers are a good place to start.

Over six years, those workers, represented by union 32BJ SEIU, doubled their hourly wages to $12 in large part because of the minimum-wage legislation. (Their employers are subcontractors of American Airlines, which contracts with the city-run Philadelphia Airport.) But the legislation was not a silver bullet. When the workers' employers did not comply with the law, 32BJ and the advocacy group POWER, one of the main advocates for the $12-an-hour minimum wage and the latest $15 bill, organized protests and lobbied city government to get American Airlines to compel its subcontractors to follow the law.

American Airlines said it couldn't comment on the bill until it was introduced.

The airport workers' story raises questions about enforcement of the law and what happens when you don't have a team of advocates fighting for your cause. Currently, the Mayor's Office of Labor enforces the $12-an-hour law. But there are challenges: Robust enforcement requires resources and staffing. The city did not immediately answer the question of whether a list of all its subcontractors exists. It will rely on city departments to provide the rates being paid to their contractors and subcontractors, Dunn said.

In an interview earlier this year, Councilwoman Helen Gym suggested that it might be time to create a new office charged with enforcing all the workplace laws on the books, instead of housing enforcement in a few different places.

Philadelphia Media Network is one of 21 news organizations producing Broke in Philly, a collaborative reporting project on solutions to poverty and the city's push toward economic justice. See all of our reporting at https://brokeinphilly.org